$JNPR
JUNIPER NETWORKS INC Stock $jnpr

$jnpr Overview Financials Valuation SEC Filings Company Website

2009 Q4 Form 10-K Financial Statement

#000144530511000332 Filed on February 25, 2011

Income Statement

Concept	2009 Q4	2009 Q3	2009 Q2
Revenue	$941.5M	$823.9M	$786.4M
YoY Change
Cost Of Revenue	$310.3M	$280.6M	$280.0M
YoY Change
Gross Profit	$631.2M	$543.3M	$506.4M
YoY Change
Gross Profit Margin	67.04%	65.94%	64.39%
Selling, General & Admin	$252.5M	$223.3M	$215.8M
YoY Change
% of Gross Profit	40.0%	41.1%	42.61%
Research & Development	$187.2M	$185.2M	$183.9M
YoY Change
% of Gross Profit	29.66%	34.09%	36.32%
Depreciation & Amortization
YoY Change
% of Gross Profit
Operating Expenses	$625.4M	$415.3M	$410.7M
YoY Change
Operating Profit	$5.800M	$128.0M	$95.70M
YoY Change
Interest Expense
YoY Change
% of Operating Profit
Other Income/Expense, Net		$100.0K
YoY Change
Pretax Income	$3.900M	$129.7M	$97.00M
YoY Change
Income Tax	-$17.20M	$45.90M	$82.20M
% Of Pretax Income	-441.03%	35.39%	84.74%
Net Earnings	$22.90M	$83.80M	$14.80M
YoY Change
Net Earnings / Revenue	2.43%	10.17%	1.88%
Basic Earnings Per Share	$0.04	$0.16	$0.03
Diluted Earnings Per Share	$0.04	$0.16	$0.03
COMMON SHARES
Basic Shares Outstanding		523.9M shares	523.1M shares
Diluted Shares Outstanding		538.1M shares

Balance Sheet

Concept	2009 Q4	2009 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$1.605B	$1.619B
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables	$458.7M
Other Receivables
Total Short-Term Assets	$2.879B
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$455.7M
YoY Change
Goodwill	$3.659B
YoY Change	0.0%
Intangibles	$13.83M
YoY Change
Long-Term Investments		$1.700M
YoY Change
Other Assets	$35.43M
YoY Change
Total Long-Term Assets	$4.711B
YoY Change
TOTAL ASSETS
Total Short-Term Assets	$2.879B
Total Long-Term Assets	$4.711B
Total Assets	$7.590B
YoY Change
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$242.6M
YoY Change
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$1.376B
YoY Change
LONG-TERM LIABILITIES
Long-Term Debt
YoY Change
Other Long-Term Liabilities	$37.53M
YoY Change
Total Long-Term Liabilities	$37.53M
YoY Change
TOTAL LIABILITIES
Total Short-Term Liabilities	$1.376B
Total Long-Term Liabilities	$37.53M
Total Liabilities	$1.413B
YoY Change
SHAREHOLDERS EQUITY
Retained Earnings	-$3.237B
YoY Change
Common Stock	$9.060B
YoY Change
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$5.822B
YoY Change
Total Liabilities & Shareholders Equity	$7.590B
YoY Change

Cashflow Statement

Concept	2009 Q4	2009 Q3	2009 Q2
OPERATING ACTIVITIES
Net Income	$22.90M	$83.80M	$14.80M
YoY Change
Depreciation, Depletion And Amortization
YoY Change
Cash From Operating Activities
YoY Change
INVESTING ACTIVITIES
Capital Expenditures
YoY Change
Acquisitions
YoY Change
Other Investing Activities
YoY Change
Cash From Investing Activities
YoY Change
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities
YoY Change
NET CHANGE
Cash From Operating Activities
Cash From Investing Activities
Cash From Financing Activities
Net Change In Cash
YoY Change
FREE CASH FLOW
Cash From Operating Activities
Capital Expenditures
Free Cash Flow
YoY Change

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2010Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	466400000	USD
CY2009Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	560400000	USD
CY2010	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	971000	USD
CY2009	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-1771000	USD
CY2008	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2009Q4	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-1800000	USD
CY2009Q3	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2009Q1	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2009Q2	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2010Q3	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-200000	USD
CY2010Q2	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-200000	USD
CY2010Q4	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-100000	USD
CY2010Q1	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	1500000	USD
CY2009Q4	us-gaap	Deferred Revenue Current DeferredRevenueCurrent	571652000	USD
CY2010Q4	us-gaap	Deferred Revenue Current DeferredRevenueCurrent	660264000	USD
CY2009	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	43672000	USD
CY2008	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	49554000	USD
CY2010	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	25193000	USD
CY2010	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2010
CY2008	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax	0	USD
CY2010	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax	0	USD
CY2009	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTax	0	USD
CY2010Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	121803000	USD
CY2009Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	13834000	USD
CY2010Q4	jnpr	Accrued Estimate Carrying Charges Or Obsolete Materials Charges AccruedEstimateCarryingChargesOrObsoleteMaterialsCharges	22700000	USD
CY2008	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	43508000	USD
CY2010	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	4230000	USD
CY2009	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	10416000	USD
CY2009Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3500000	USD
CY2009Q4	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1200000	USD
CY2009Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1300000	USD
CY2009Q1	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	4400000	USD
CY2010Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1200000	USD
CY2010Q4	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	900000	USD
CY2010Q1	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1100000	USD
CY2010Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	900000	USD
CY2008	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Other Share Increase Decrease During Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOtherShareIncreaseDecreaseDuringPeriodWeightedAverageExercisePrice	22.03
CY2010	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Other Share Increase Decrease During Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOtherShareIncreaseDecreaseDuringPeriodWeightedAverageExercisePrice	22.03
CY2009	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Other Share Increase Decrease During Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOtherShareIncreaseDecreaseDuringPeriodWeightedAverageExercisePrice	21.57
CY2008	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	2910960000	USD
CY2009	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	2567992000	USD
CY2010	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	3258651000	USD
CY2009Q3	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	634100000	USD
CY2009Q2	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	607000000	USD
CY2009Q4	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	739100000	USD
CY2009Q1	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	587800000	USD
CY2010Q1	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	721200000	USD
CY2010Q3	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	801200000	USD
CY2010Q2	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	774100000	USD
CY2010Q4	us-gaap	Sales Revenue Goods Net SalesRevenueGoodsNet	962200000	USD
CY2009	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	73500000	USD
CY2008	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	1300000	USD
CY2010	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2010	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	57500000	USD
CY2009	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-42700000	USD
CY2008	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	21400000	USD
CY2010	jnpr	Nonemployee Director Rsu Annual Grant Value NonemployeeDirectorRsuAnnualGrantValue	125000	USD
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice	21.79
CY2010Q4	us-gaap	Assets Current AssetsCurrent	3214370000	USD
CY2009Q4	us-gaap	Assets Current AssetsCurrent	2878959000	USD
CY2010Q4	us-gaap	Business Acquisition Purchase Price Allocation Goodwill Amount BusinessAcquisitionPurchasePriceAllocationGoodwillAmount	269200000	USD
CY2010	us-gaap	Finite Lived Intangible Assets Future Amortization Expense FiniteLivedIntangibleAssetsFutureAmortizationExpense	113900000	USD
CY2010Q4	us-gaap	Minority Interest MinorityInterest	600000	USD
CY2009Q4	us-gaap	Minority Interest MinorityInterest	2629000	USD
CY2009Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	922551000	USD
CY2010Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1065408000	USD
CY2010Q4	us-gaap	Business Acquisition Purchase Price Allocation Goodwill Expected Tax Deductible Amount BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount	0	USD
CY2010Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	296300000	USD
CY2006Q3	us-gaap	Loss Contingency New Claims Filed Number LossContingencyNewClaimsFiledNumber	2	pure
CY2010Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	59087000	USD
CY2009Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	37531000	USD
CY2008	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	474007000	USD
CY2009	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	1461532000	USD
CY2010	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	1577758000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableIntrinsicValue	516100000	USD
CY2010	jnpr	Number Of Issuers Against Which Class Action Has Been Filed NumberOfIssuersAgainstWhichClassActionHasBeenFiled	300	pure
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	800000	shares
CY2009	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	5200000	shares
CY2008	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	900000	shares
CY2008	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-4400000	USD
CY2010	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	14000000	USD
CY2009	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	55700000	USD
CY2009	jnpr	Effective Income Tax Rate Reconciliation Temporary Differences EffectiveIncomeTaxRateReconciliationTemporaryDifferences	72800000	USD
CY2008	jnpr	Effective Income Tax Rate Reconciliation Temporary Differences EffectiveIncomeTaxRateReconciliationTemporaryDifferences	0	USD
CY2010	jnpr	Effective Income Tax Rate Reconciliation Temporary Differences EffectiveIncomeTaxRateReconciliationTemporaryDifferences	10200000	USD
CY2009	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	741708000	USD
CY2008	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	731151000	USD
CY2010	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	917855000	USD
CY2009Q4	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	187200000	USD
CY2009Q1	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	185400000	USD
CY2009Q2	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	183900000	USD
CY2009Q3	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	185200000	USD
CY2010Q4	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	254900000	USD
CY2010Q2	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	224800000	USD
CY2010Q1	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	207000000	USD
CY2010Q3	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	231200000	USD
CY2010	us-gaap	Use Of Estimates UseOfEstimates	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Use of Estimates</font><font style="font-family:Arial;font-size:10pt;"> </font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"> </font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">The preparation of the financial statements and related disclosures in conformity with U.S. GAAP requires the Company to make judgments, assumptions, and estimates that affect the amounts reported in the consolidated financial statements and the accompanying notes. The Company bases its estimates and assumptions on current facts, historical experience, and various other factors that it believes are reasonable under the circumstances, to determine the carrying values of assets and liabilities that are not readily apparent from other sources. To the extent there are material differences between our estimates and the actual results, our future consolidated results of operation may be affected.</font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"> </font></div></div>
CY2010	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2010	jnpr	Gross Unrealized Gains Due Between One And Five Years GrossUnrealizedGainsDueBetweenOneAndFiveYears	2200000	USD
CY2009	jnpr	Gross Unrealized Gains Due Between One And Five Years GrossUnrealizedGainsDueBetweenOneAndFiveYears	2000000	USD
CY2009Q4	jnpr	Prepaid Expenses And Other Current Assets PrepaidExpensesAndOtherCurrentAssets	48744000	USD
CY2010Q4	jnpr	Prepaid Expenses And Other Current Assets PrepaidExpensesAndOtherCurrentAssets	169812000	USD
CY2010	jnpr	Stock Repurchased And Retired During Period Under Repurchase Plans Value StockRepurchasedAndRetiredDuringPeriodUnderRepurchasePlansValue	-563500000	USD
CY2009	jnpr	Stock Repurchased And Retired During Period Under Repurchase Plans Value StockRepurchasedAndRetiredDuringPeriodUnderRepurchasePlansValue	-453500000	USD
CY2010Q4	jnpr	Outstanding Stock Options And Restricted Stock Units Covering Shares Of Common Stock OutstandingStockOptionsAndRestrictedStockUnitsCoveringSharesOfCommonStock	2100000	shares
CY2008	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	-288000	USD
CY2009	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	0	USD
CY2010	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	0	USD
CY2008	us-gaap	Increase Decrease In Other Accrued Liabilities IncreaseDecreaseInOtherAccruedLiabilities	-6702000	USD
CY2009	us-gaap	Increase Decrease In Other Accrued Liabilities IncreaseDecreaseInOtherAccruedLiabilities	30457000	USD
CY2010	us-gaap	Increase Decrease In Other Accrued Liabilities IncreaseDecreaseInOtherAccruedLiabilities	3681000	USD
CY2010	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-72421000	USD
CY2008	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-422393000	USD
CY2009	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-262158000	USD
CY2009	us-gaap	Restructuring Reserve Settled With Cash RestructuringReserveSettledWithCash	8300000	USD
CY2010	us-gaap	Restructuring Reserve Settled With Cash RestructuringReserveSettledWithCash	8000000	USD
CY2009	jnpr	Common Stock Repurchased Under Stock Repurchase Program Average Purchase Price CommonStockRepurchasedUnderStockRepurchaseProgramAveragePurchasePrice	21.91
CY2010	jnpr	Common Stock Repurchased Under Stock Repurchase Program Average Purchase Price CommonStockRepurchasedUnderStockRepurchaseProgramAveragePurchasePrice	28.67
CY2009Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	35425000	USD
CY2010Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	55466000	USD
CY2010	jnpr	Common Stock For Each Share Subject To Rsus And Psas CommonStockForEachShareSubjectToRsusAndPsas	2.1	pure
CY2009Q4	us-gaap	Litigation Reserve Current LitigationReserveCurrent	169330000	USD
CY2010Q4	us-gaap	Litigation Reserve Current LitigationReserveCurrent	0	USD
CY2010	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2010Q4	jnpr	Indemnity Related Escrow Amount IndemnityRelatedEscrowAmount	65000000	USD
CY2010	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2010	jnpr	Contractual Period ContractualPeriod	one to three years
CY2008	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	-400000	USD
CY2009	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	-12800000	USD
CY2010	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	-1600000	USD
CY2010Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Outstanding Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions	49400000	shares
CY2010	jnpr	Warranty Period Software WarrantyPeriodSoftware	90	pure
CY2009Q4	us-gaap	Standard Product Warranty Accrual Current StandardProductWarrantyAccrualCurrent	38199000	USD
CY2010Q4	us-gaap	Standard Product Warranty Accrual Current StandardProductWarrantyAccrualCurrent	35931000	USD
CY2010Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	10110000	USD
CY2009Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	9116000	USD
CY2010	us-gaap	Future Amortization Expense Year One FutureAmortizationExpenseYearOne	23300000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	66300000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	86100000	USD
CY2010	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Option Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisesInPeriodWeightedAverageExercisePrice	18.99
CY2009	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Option Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisesInPeriodWeightedAverageExercisePrice	14.59
CY2008	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Option Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisesInPeriodWeightedAverageExercisePrice	14.49
CY2010	jnpr	Restricted Stock Units And Performance Share Awards Weighted Average Remaining Contractual Term RestrictedStockUnitsAndPerformanceShareAwardsWeightedAverageRemainingContractualTerm	1.7	pure
CY2010	us-gaap	Employee Service Share Based Compensation Unrecognized Compensation Costs On Nonvested Awards Weighted Average Period Of Recognition EmployeeServiceShareBasedCompensationUnrecognizedCompensationCostsOnNonvestedAwardsWeightedAveragePeriodOfRecognition	2.3	pure
CY2009	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2008	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2010	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	374765000	USD
CY2009Q2	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	179400000	USD
CY2008	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-2700000	USD
CY2009	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-5900000	USD
CY2010	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-7500000	USD
CY2010Q4	us-gaap	Business Acquisition Cost Of Acquired Entity Other Noncash Consideration BusinessAcquisitionCostOfAcquiredEntityOtherNoncashConsideration	6100000	USD
CY2010Q2	us-gaap	Business Acquisition Cost Of Acquired Entity Other Noncash Consideration BusinessAcquisitionCostOfAcquiredEntityOtherNoncashConsideration	10700000	USD
CY2010	us-gaap	Property Plant And Equipment Useful Life Minimum PropertyPlantAndEquipmentUsefulLifeMinimum	1.5	pure
CY2010Q4	us-gaap	Acquired Finite Lived Intangible Asset Amount AcquiredFiniteLivedIntangibleAssetAmount	108600000	USD
CY2009Q4	us-gaap	Acquired Finite Lived Intangible Asset Amount AcquiredFiniteLivedIntangibleAssetAmount	0	USD
CY2010	jnpr	Thereafter Thereafter	8800000	USD
CY2009	us-gaap	Operating Expenses OperatingExpenses	1872508000	USD
CY2010	us-gaap	Operating Expenses OperatingExpenses	1974163000	USD
CY2008	us-gaap	Operating Expenses OperatingExpenses	1740509000	USD
CY2009Q1	us-gaap	Operating Expenses OperatingExpenses	421100000	USD
CY2009Q4	us-gaap	Operating Expenses OperatingExpenses	625400000	USD
CY2009Q3	us-gaap	Operating Expenses OperatingExpenses	415300000	USD
CY2009Q2	us-gaap	Operating Expenses OperatingExpenses	410700000	USD
CY2010Q2	us-gaap	Operating Expenses OperatingExpenses	474900000	USD
CY2010Q3	us-gaap	Operating Expenses OperatingExpenses	482300000	USD
CY2010Q4	us-gaap	Operating Expenses OperatingExpenses	565200000	USD
CY2010Q1	us-gaap	Operating Expenses OperatingExpenses	451700000	USD
CY2010Q4	jnpr	Amount Of Restricted Investments Measured At Fair Value Included In Balance Of Government Securities AmountOfRestrictedInvestmentsMeasuredAtFairValueIncludedInBalanceOfGovernmentSecurities	600000	USD
CY2010	us-gaap	Restructuring Reserve Period Expense RestructuringReservePeriodExpense	10805000	USD
CY2009	us-gaap	Restructuring Reserve Period Expense RestructuringReservePeriodExpense	19463000	USD
CY2008	us-gaap	Restructuring Reserve Period Expense RestructuringReservePeriodExpense	0	USD
CY2010Q4	us-gaap	Trading Securities Fair Value Disclosure TradingSecuritiesFairValueDisclosure	8100000	USD
CY2009Q4	us-gaap	Trading Securities Fair Value Disclosure TradingSecuritiesFairValueDisclosure	4700000	USD
CY2010Q4	jnpr	Restricted Stock Units And Performance Share Awards Aggregate Intrinsic Value RestrictedStockUnitsAndPerformanceShareAwardsAggregateIntrinsicValue	522900000	USD
CY2009	us-gaap	Product Warranty Accrual Warranties Issued ProductWarrantyAccrualWarrantiesIssued	46900000	USD
CY2010	us-gaap	Product Warranty Accrual Warranties Issued ProductWarrantyAccrualWarrantiesIssued	49900000	USD
CY2008	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	661416000	USD
CY2009	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	747920000	USD
CY2010	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	834615000	USD
CY2009Q1	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	176300000	USD
CY2009Q3	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	189800000	USD
CY2009Q4	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	202400000	USD
CY2010Q4	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	227800000	USD
CY2010Q2	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	204200000	USD
CY2010Q1	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	191400000	USD
CY2010Q3	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	211200000	USD
CY2010Q4	jnpr	Liabilitiy For Uncertain Tax Position LiabilitiyForUncertainTaxPosition	103900000	USD
CY2008	jnpr	Effectivetaxratereonciliationrearchcredits Effectivetaxratereonciliationrearchcredits	12100000	USD
CY2009	jnpr	Effectivetaxratereonciliationrearchcredits Effectivetaxratereonciliationrearchcredits	14400000	USD
CY2010	jnpr	Effectivetaxratereonciliationrearchcredits Effectivetaxratereonciliationrearchcredits	18600000	USD
CY2010	dei	Amendment Flag AmendmentFlag	false
CY2010Q4	jnpr	Principal Contractual Obligations Total PrincipalContractualObligationsTotal	693900000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Net Current DeferredTaxAssetsNetCurrent	161535000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Net Current DeferredTaxAssetsNetCurrent	196318000	USD
CY2010Q4	jnpr	Fair Value Liabilities Measured On Nonrecurring Basis Liabilities FairValueLiabilitiesMeasuredOnNonrecurringBasisLiabilities	0	USD
CY2009Q4	jnpr	Fair Value Liabilities Measured On Nonrecurring Basis Liabilities FairValueLiabilitiesMeasuredOnNonrecurringBasisLiabilities	0	USD
CY2010	jnpr	Gross Unrealized Losses No Contractual Maturity GrossUnrealizedLossesNoContractualMaturity	0	USD
CY2009	jnpr	Gross Unrealized Losses No Contractual Maturity GrossUnrealizedLossesNoContractualMaturity	0	USD
CY2010Q4	jnpr	Amount Of Restricted Investments Measured At Fair Value Included In Balance Of Corporate Debt Securities AmountOfRestrictedInvestmentsMeasuredAtFairValueIncludedInBalanceOfCorporateDebtSecurities	2700000	USD
CY2010Q4	us-gaap	Business Acquisition Purchase Price Allocation Assets Acquired Liabilities Assumed Net BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet	8800000	USD
CY2009	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	-1000000	USD
CY2010	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	-73800000	USD
CY2008	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2009	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-2757000	USD
CY2010	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-317000	USD
CY2008	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	2547000	USD
CY2009	jnpr	Effectiveincometaxratereconciliationfederalrate Effectiveincometaxratereconciliationfederalrate	-109200000	USD
CY2010	jnpr	Effectiveincometaxratereconciliationfederalrate Effectiveincometaxratereconciliationfederalrate	-272400000	USD
CY2008	jnpr	Effectiveincometaxratereconciliationfederalrate Effectiveincometaxratereconciliationfederalrate	-255100000	USD
CY2009	us-gaap	Other Comprehensive Income Loss Net Of Tax Period Increase Decrease OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease	2812000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Net Of Tax Period Increase Decrease OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease	182000	USD
CY2008	us-gaap	Other Comprehensive Income Loss Net Of Tax Period Increase Decrease OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease	-16396000	USD
CY2010	jnpr	Gross Unrealized Gains Due Within One Year GrossUnrealizedGainsDueWithinOneYear	900000	USD
CY2009	jnpr	Gross Unrealized Gains Due Within One Year GrossUnrealizedGainsDueWithinOneYear	1000000	USD
CY2008	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	604700000	USD
CY2010	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	565473000	USD
CY2009	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	453888000	USD
CY2010Q4	us-gaap	Deferred Compensation Liability Current DeferredCompensationLiabilityCurrent	8100000	USD
CY2009Q4	us-gaap	Deferred Compensation Liability Current DeferredCompensationLiabilityCurrent	4700000	USD
CY2010	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2008	us-gaap	Depreciation And Amortization DepreciationAndAmortization	123469000	USD
CY2010	us-gaap	Depreciation And Amortization DepreciationAndAmortization	146757000	USD
CY2009	us-gaap	Depreciation And Amortization DepreciationAndAmortization	132974000	USD
CY2010	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	4188000	USD
CY2008	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	2458000	USD
CY2009	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	6205000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Net Noncurrent DeferredTaxAssetsNetNoncurrent	10555000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Net Noncurrent DeferredTaxAssetsNetNoncurrent	0	USD
CY2008	us-gaap	Stock Issued During Period Shares Conversion Of Convertible Securities StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	19822000	shares
CY2010	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2009	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2009	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	796097000	USD
CY2010	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	812335000	USD
CY2008	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	875179000	USD
CY2010Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.00001	USD
CY2009Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.00001	USD
CY2010Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	292270000	USD
CY2009Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	242591000	USD
CY2010Q4	jnpr	Indefinitely Invested Undistributed Earnings IndefinitelyInvestedUndistributedEarnings	1200000000	USD
CY2010	jnpr	Possible Decrease In Gross Unrecognized Tax Benefits Within Next Twelve Months PossibleDecreaseInGrossUnrecognizedTaxBenefitsWithinNextTwelveMonths	-8100000	USD
CY2009	jnpr	Investment In Privately Held Companies InvestmentInPrivatelyHeldCompanies	7200000	USD
CY2008	jnpr	Investment In Privately Held Companies InvestmentInPrivatelyHeldCompanies	4600000	USD
CY2010	jnpr	Investment In Privately Held Companies InvestmentInPrivatelyHeldCompanies	13300000	USD
CY2009Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-3236525000	USD
CY2010Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-3108337000	USD
CY2010	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.18
CY2008	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.96
CY2009	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.22
CY2009Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.16
CY2009Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.03
CY2009Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.01
CY2009Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.04
CY2010Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.36
CY2010Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.26
CY2010Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.25
CY2010Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.31
CY2009Q4	us-gaap	Stockholders Equity StockholdersEquity	5822136000	USD
CY2010Q4	us-gaap	Stockholders Equity StockholdersEquity	6608200000	USD
CY2010	jnpr	Number Of Days Elapsed Since Receipt Of Last Award NumberOfDaysElapsedSinceReceiptOfLastAward	365	pure
CY2010Q4	jnpr	Vested And Expected To Vest Restricted Stock Units And Performance Share Awards Number Of Shares VestedAndExpectedToVestRestrictedStockUnitsAndPerformanceShareAwardsNumberOfShares	12100000	shares
CY2010	jnpr	Shares Repuchased And Retired Related To Net Issuances SharesRepuchasedAndRetiredRelatedToNetIssuances	1900000	USD
CY2008	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	164604000	USD
CY2010	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	185291000	USD
CY2009	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	153101000	USD
CY2009	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	19613000	USD
CY2008	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	22963000	USD
CY2010	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-3487000	USD
CY2010Q4	jnpr	Accumulated Impairment Losses AccumulatedImpairmentLosses	1280000000	USD
CY2008Q4	jnpr	Accumulated Impairment Losses AccumulatedImpairmentLosses	1280000000	USD
CY2009Q4	jnpr	Accumulated Impairment Losses AccumulatedImpairmentLosses	1280000000	USD
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue	713900000	USD
CY2010Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	35000000	USD
CY2010	us-gaap	Future Amortization Expense Year Two FutureAmortizationExpenseYearTwo	22500000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Remaining Contractual Term ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm	4.1	pure
CY2010Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Exercisable Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions	32100000	shares
CY2009Q4	us-gaap	Goodwill Goodwill	3658602000	USD
CY2010Q4	us-gaap	Goodwill Goodwill	3927807000	USD
CY2008Q4	us-gaap	Goodwill Goodwill	3658600000	USD
CY2008	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	217142000	USD
CY2009	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	196833000	USD
CY2010	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	158781000	USD
CY2009Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	82200000	USD
CY2009Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	85900000	USD
CY2009Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-17200000	USD
CY2009Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	45900000	USD
CY2010Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-2900000	USD
CY2010Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	61400000	USD
CY2010Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	41500000	USD
CY2010Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	58700000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	112800000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	122200000	USD
CY2010	jnpr	Deferred Incometax Expense Benefit Net DeferredIncometaxExpenseBenefitNet	64035000	USD
CY2008	jnpr	Deferred Incometax Expense Benefit Net DeferredIncometaxExpenseBenefitNet	14314000	USD
CY2009	jnpr	Deferred Incometax Expense Benefit Net DeferredIncometaxExpenseBenefitNet	9436000	USD
CY2010	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Upper Range Limit ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit	115.48
CY2010	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2008	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	108133000	USD
CY2010	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	177825000	USD
CY2009	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	139659000	USD
CY2010	jnpr	Weighted Average Period Of Unrecognized Compensation Cost Related To Unvested Restricted Stock Units In Years WeightedAveragePeriodOfUnrecognizedCompensationCostRelatedToUnvestedRestrictedStockUnitsInYears	2.3	pure
CY2009	us-gaap	Gain Loss On Investments GainLossOnInvestments	-5562000	USD
CY2008	us-gaap	Gain Loss On Investments GainLossOnInvestments	-14832000	USD
CY2010	us-gaap	Gain Loss On Investments GainLossOnInvestments	8653000	USD
CY2009Q4	us-gaap	Gain Loss On Investments GainLossOnInvestments	-2200000	USD
CY2009Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	-1600000	USD
CY2009Q1	us-gaap	Gain Loss On Investments GainLossOnInvestments	-1700000	USD
CY2009Q3	us-gaap	Gain Loss On Investments GainLossOnInvestments	0	USD
CY2010Q1	us-gaap	Gain Loss On Investments GainLossOnInvestments	0	USD
CY2010Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	3200000	USD
CY2010Q3	us-gaap	Gain Loss On Investments GainLossOnInvestments	0	USD
CY2010Q4	us-gaap	Gain Loss On Investments GainLossOnInvestments	5400000	USD
CY2010Q4	jnpr	Closing Stock Price At Plan Period End ClosingStockPriceAtPlanPeriodEnd	36.92
CY2010	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	269000000	USD
CY2010	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	48217000	USD
CY2008	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	19770000	USD
CY2009	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	-2422000	USD
CY2009	jnpr	Fair Value Transfers Of Assets And Liabilities Between Levels Of Fair Value Hierarchy FairValueTransfersOfAssetsAndLiabilitiesBetweenLevelsOfFairValueHierarchy	0	USD
CY2010	jnpr	Fair Value Transfers Of Assets And Liabilities Between Levels Of Fair Value Hierarchy FairValueTransfersOfAssetsAndLiabilitiesBetweenLevelsOfFairValueHierarchy	0	USD
CY2009	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	0	USD
CY2008	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	399208000	USD
CY2010	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	0	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	6200000	shares
CY2009	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	9900000	shares
CY2008	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	15700000	shares
CY2010Q4	jnpr	Maximum Additional Shares Expire Unexercised Under1996 And2000 Plan MaximumAdditionalSharesExpireUnexercisedUnder1996And2000Plan	75000000	shares
CY2010	jnpr	Share Based Payroll Tax Expense ShareBasedPayrollTaxExpense	6433000	USD
CY2009	jnpr	Share Based Payroll Tax Expense ShareBasedPayrollTaxExpense	832000	USD
CY2008	jnpr	Share Based Payroll Tax Expense ShareBasedPayrollTaxExpense	2763000	USD
CY2010	jnpr	Leasehold Improvement Depreciation Maximum Life LeaseholdImprovementDepreciationMaximumLife	10	pure
CY2010	us-gaap	Finite Lived Intangible Assets Useful Life Maximum FiniteLivedIntangibleAssetsUsefulLifeMaximum	19	pure
CY2010Q4	us-gaap	Short Term Investments ShortTermInvestments	474514000	USD
CY2009Q4	us-gaap	Short Term Investments ShortTermInvestments	570522000	USD
CY2010	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	36800000	USD
CY2008	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	171700000	USD
CY2009	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	188700000	USD
CY2008	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
CY2010	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
CY2009	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	44000000	shares
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	32100000	shares
CY2010	us-gaap	Share Based Compensation ShareBasedCompensation	177825000	USD
CY2009	us-gaap	Share Based Compensation ShareBasedCompensation	139659000	USD
CY2008	us-gaap	Share Based Compensation ShareBasedCompensation	108133000	USD
CY2010Q4	us-gaap	Employee Service Share Based Compensation Unrecognized Compensation Costs On Nonvested Awards EmployeeServiceShareBasedCompensationUnrecognizedCompensationCostsOnNonvestedAwards	109300000	USD
CY2010Q4	jnpr	Vested And Expected To Vest Restricted Stock Units And Performance Share Awards Weighted Average Grant Date Fair Value VestedAndExpectedToVestRestrictedStockUnitsAndPerformanceShareAwardsWeightedAverageGrantDateFairValue	25.70
CY2010	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	182000000	USD
CY2008	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	108100000	USD
CY2009	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	139700000	USD
CY2010Q4	us-gaap	Preferred Stock Value Outstanding PreferredStockValueOutstanding	0	USD
CY2009Q4	us-gaap	Preferred Stock Value Outstanding PreferredStockValueOutstanding	0	USD
CY2010	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	207164000	USD
CY2009	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-414361000	USD
CY2008	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	302974000	USD
CY2010	jnpr	Common Stock Average Purchase Price CommonStockAveragePurchasePrice	25.75
CY2010	jnpr	Number Of Days Due From Receivable NumberOfDaysDueFromReceivable	30	pure
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	21.90
CY2008Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	21.24
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	20.84
CY2007Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	20.36
CY2010	jnpr	Effectivetaxratereconciliationforeignratedifferential Effectivetaxratereconciliationforeignratedifferential	71500000	USD
CY2008	jnpr	Effectivetaxratereconciliationforeignratedifferential Effectivetaxratereconciliationforeignratedifferential	51200000	USD
CY2009	jnpr	Effectivetaxratereconciliationforeignratedifferential Effectivetaxratereconciliationforeignratedifferential	33800000	USD
CY2010	jnpr	Reclassification Time Of Other Comprehensive Income Loss Into Income ReclassificationTimeOfOtherComprehensiveIncomeLossIntoIncome	within the next 12 months
CY2010	us-gaap	Business Combination Pro Forma Information Disclosure Impracticable BusinessCombinationProFormaInformationDisclosureImpracticable	0
CY2010	us-gaap	Guarantees Indemnifications And Warranties Policies GuaranteesIndemnificationsAndWarrantiesPolicies	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Warranty Costs</font><font style="font-family:Arial;font-size:10pt;"> </font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"> </font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">The Company generally offers a </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">one</font><font style="font-family:inherit;font-size:10pt;">-year warranty on all of its hardware products and a </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">90</font><font style="font-family:inherit;font-size:10pt;">-day warranty on the media that contains the software embedded in the products. Warranty costs are accrued as part of the Company's cost of sales based on associated material costs, labor costs for customer support, and overhead at the time revenue is recognized. Material costs are estimated primarily based upon the historical costs to repair or replace product returns within the warranty period. Customer support labor and overhead costs are estimated primarily based upon historical trends in the cost to support customer cases within the warranty period. </font></div></div>
CY2009	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease	5569000	USD
CY2010	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease	499000	USD
CY2008	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease	-19043000	USD
CY2010	us-gaap	Future Amortization Expense Year Three FutureAmortizationExpenseYearThree	22300000	USD
CY2010	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	522444000	shares
CY2009	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	523603000	shares
CY2008	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	530337000	shares
CY2010	us-gaap	Product Warranty Accrual Preexisting Increase Decrease ProductWarrantyAccrualPreexistingIncreaseDecrease	-3000000	USD
CY2009	us-gaap	Product Warranty Accrual Preexisting Increase Decrease ProductWarrantyAccrualPreexistingIncreaseDecrease	-5600000	USD
CY2009	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Grant In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantInPeriodWeightedAverageExercisePrice	17.86
CY2010	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Grant In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantInPeriodWeightedAverageExercisePrice	29.15
CY2008	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Grant In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantInPeriodWeightedAverageExercisePrice	23.08
CY2009	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	759131000	USD
CY2010	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	857072000	USD
CY2008	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	812013000	USD
CY2009Q2	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	176600000	USD
CY2009Q3	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	183400000	USD
CY2009Q4	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	211300000	USD
CY2009Q1	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	187900000	USD
CY2010Q1	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	192400000	USD
CY2010Q3	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	204700000	USD
CY2010Q2	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	202300000	USD
CY2010Q4	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	257700000	USD
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	18000000	shares
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	30700000	shares
CY2010Q4	us-gaap	Business Acquisition Cost Of Acquired Entity Equity Interests Issued And Issuable BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable	2400000	USD
CY2010	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	200000	USD
CY2009	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments		USD
CY2010	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	619555000	USD
CY2009	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	118040000	USD
CY2008	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	495253000	USD
CY2010	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	563526000	USD
CY2009	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	453888000	USD
CY2008	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	604700000	USD
CY2008	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	48749000	USD
CY2009	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	6928000	USD
CY2010	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	1917000	USD
CY2009Q2	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	2900000	USD
CY2009Q4	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	300000	USD
CY2009Q3	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	1700000	USD
CY2009Q1	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	2000000	USD
CY2010Q1	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	1400000	USD
CY2010Q4	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	-600000	USD
CY2010Q3	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	200000	USD
CY2010Q2	jnpr	Interest And Other Income Net InterestAndOtherIncomeNet	800000	USD
CY2008Q4	jnpr	Gross Goodwill GrossGoodwill	4938600000	USD
CY2009Q4	jnpr	Gross Goodwill GrossGoodwill	4938600000	USD
CY2010Q4	jnpr	Gross Goodwill GrossGoodwill	5207800000	USD
CY2010Q2	dei	Entity Public Float EntityPublicFloat	8678000000	USD
CY2009	us-gaap	Payments To Acquire Interest In Joint Venture PaymentsToAcquireInterestInJointVenture	6600000	USD
CY2008	jnpr	Customers Accounting For Ten Percent Or More Of Companys Net Revenues CustomersAccountingForTenPercentOrMoreOfCompanysNetRevenues	0	pure
CY2010Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	493881000	USD
CY2009Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	455651000	USD
CY2009Q4	us-gaap	Long Term Investments LongTermInvestments	483505000	USD
CY2010Q4	us-gaap	Long Term Investments LongTermInvestments	535178000	USD
CY2010Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	465500000	USD
CY2009Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	559400000	USD
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	25.94
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	21.76
CY2007Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	22.40
CY2008Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	24.59
CY2008	jnpr	Exercise Of Warrants In Connection With Acquisitions Shares ExerciseOfWarrantsInConnectionWithAcquisitionsShares	8000	shares
CY2010Q4	us-gaap	Restricted Cash And Investments Noncurrent RestrictedCashAndInvestmentsNoncurrent	119346000	USD
CY2009Q4	us-gaap	Restricted Cash And Investments Noncurrent RestrictedCashAndInvestmentsNoncurrent	53732000	USD
CY2009Q4	jnpr	Percent Of Property And Equipment Held In Us PercentOfPropertyAndEquipmentHeldInUs	0.81	pure
CY2010Q4	jnpr	Percent Of Property And Equipment Held In Us PercentOfPropertyAndEquipmentHeldInUs	0.8	pure
CY2010Q4	jnpr	Purchased Intangible Assets Accumulated Amortization PurchasedIntangibleAssetsAccumulatedAmortization	443600000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals	264500000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals	227600000	USD
CY2010Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	525378000	shares
CY2009Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	519341000	shares
CY2009Q4	us-gaap	Notional Amount Of Foreign Currency Derivative Instruments Not Designated As Hedging Instruments NotionalAmountOfForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments	54700000	USD
CY2010Q4	us-gaap	Notional Amount Of Foreign Currency Derivative Instruments Not Designated As Hedging Instruments NotionalAmountOfForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments	74400000	USD
CY2010	us-gaap	Available For Sale Securities Gross Unrealized Loss AvailableForSaleSecuritiesGrossUnrealizedLoss	500000	USD
CY2009	us-gaap	Available For Sale Securities Gross Unrealized Loss AvailableForSaleSecuritiesGrossUnrealizedLoss	700000	USD
CY2008	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	0	USD
CY2010	us-gaap	Future Amortization Expense Year Four FutureAmortizationExpenseYearFour	20400000	USD
CY2008	jnpr	Average Price Of Common Stock Per Share AveragePriceOfCommonStockPerShare	22.57
CY2010	jnpr	Average Price Of Common Stock Per Share AveragePriceOfCommonStockPerShare	21.20
CY2009	jnpr	Average Price Of Common Stock Per Share AveragePriceOfCommonStockPerShare	12.16
CY2009	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	0	USD
CY2010	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	0	USD
CY2010Q4	us-gaap	Equity Method Investment Ownership Percentage EquityMethodInvestmentOwnershipPercentage	0.60	pure
CY2010Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2009Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2010Q4	jnpr	Program Licensing And Technical Support ProgramLicensingAndTechnicalSupport	9200000	USD
CY2010	jnpr	Rsu Vest Schedule Director RsuVestScheduleDirector	1	pure
CY2008	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	551433000	shares
CY2010	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	538790000	shares
CY2009	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	534015000	shares
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	20.91
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	20.96
CY2010	jnpr	Maturity Period Of Non Designated Hedges Derivatives MaturityPeriodOfNonDesignatedHedgesDerivatives	approximately two months
CY2008	us-gaap	Incremental Common Shares Attributable To Conversion Of Debt Securities IncrementalCommonSharesAttributableToConversionOfDebtSecurities	8829000	shares
CY2010	us-gaap	Incremental Common Shares Attributable To Conversion Of Debt Securities IncrementalCommonSharesAttributableToConversionOfDebtSecurities	0	shares
CY2009	us-gaap	Incremental Common Shares Attributable To Conversion Of Debt Securities IncrementalCommonSharesAttributableToConversionOfDebtSecurities	0	shares
CY2010Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	443600000	USD
CY2009Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	435100000	USD
CY2010	jnpr	Effectivetaxreconciliationotheradjustments Effectivetaxreconciliationotheradjustments	-300000	USD
CY2008	jnpr	Effectivetaxreconciliationotheradjustments Effectivetaxreconciliationotheradjustments	-6400000	USD
CY2009	jnpr	Effectivetaxreconciliationotheradjustments Effectivetaxreconciliationotheradjustments	-2500000	USD
CY2008	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	147999000	USD
CY2009	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	139969000	USD
CY2010	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	155700000	USD
CY2010Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	8467851000	USD
CY2009Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	7590263000	USD
CY2010	us-gaap	Finite Lived Intangible Assets Useful Life Minimum FiniteLivedIntangibleAssetsUsefulLifeMinimum	2	pure
CY2010	jnpr	Available For Sale Investments And Publicly Traded Securities Unrealized Loss AvailableForSaleInvestmentsAndPubliclyTradedSecuritiesUnrealizedLoss	500000	USD
CY2009	jnpr	Available For Sale Investments And Publicly Traded Securities Unrealized Loss AvailableForSaleInvestmentsAndPubliclyTradedSecuritiesUnrealizedLoss	700000	USD
CY2010Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	231600000	USD
CY2010Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	189000000	USD
CY2010Q4	us-gaap	Acquired Indefinite Lived Intangible Asset Amount AcquiredIndefiniteLivedIntangibleAssetAmount	7900000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	418400000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	416500000	USD
CY2009Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	183600000	USD
CY2010Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	116400000	USD
CY2008Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	113500000	USD
CY2007Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	94700000	USD
CY2009	jnpr	Cash Payment From Acquisition Of Publicly Traded Company CashPaymentFromAcquisitionOfPubliclyTradedCompany	1000000	USD
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	744500000	USD
CY2008	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	172453000	USD
CY2009	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	148373000	USD
CY2010	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	155288000	USD
CY2008	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	2900000	USD
CY2009	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	14800000	USD
CY2010	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	-4600000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Remaining Contractual Term ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm	4.1	pure
CY2009Q4	us-gaap	Standard Product Warranty Accrual StandardProductWarrantyAccrual	38200000	USD
CY2008Q4	us-gaap	Standard Product Warranty Accrual StandardProductWarrantyAccrual	40100000	USD
CY2010Q4	us-gaap	Standard Product Warranty Accrual StandardProductWarrantyAccrual	35900000	USD
CY2010	us-gaap	Proceeds From Sale And Collection Of Receivables ProceedsFromSaleAndCollectionOfReceivables	595700000	USD
CY2009	us-gaap	Proceeds From Sale And Collection Of Receivables ProceedsFromSaleAndCollectionOfReceivables	426300000	USD
CY2010Q4	us-gaap	Business Acquisition Cost Of Acquired Entity Cash Paid BusinessAcquisitionCostOfAcquiredEntityCashPaid	392100000	USD
CY2010Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	100000	USD
CY2009Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	300000	USD
CY2009Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	458652000	USD
CY2010Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	596622000	USD
CY2008	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	728891000	USD
CY2010	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	778154000	USD
CY2009	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	312061000	USD
CY2009Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	3900000	USD
CY2009Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	97000000	USD
CY2009Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	81500000	USD
CY2010Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	195700000	USD
CY2010Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	161700000	USD
CY2009	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	43500000	USD
CY2009Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	129700000	USD
CY2009	jnpr	Repurchase Of Common Stock From Employees For Net Issuance Of Shares RepurchaseOfCommonStockFromEmployeesForNetIssuanceOfShares	0	shares
CY2010	jnpr	Derivative Instrument Ineffectiveness Is Immaterial DerivativeInstrumentIneffectivenessIsImmaterial	immaterial
CY2008	jnpr	Derivative Instrument Ineffectiveness Is Immaterial DerivativeInstrumentIneffectivenessIsImmaterial	immaterial
CY2009	jnpr	Derivative Instrument Ineffectiveness Is Immaterial DerivativeInstrumentIneffectivenessIsImmaterial	immaterial
CY2010Q4	jnpr	Other Contractual Obligations OtherContractualObligations	95100000	USD
CY2009	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	20715000	shares
CY2010	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	19654000	shares
CY2008	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	25088000	shares
CY2008	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	39300000	USD
CY2010	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	44200000	USD
CY2010Q4	us-gaap	Notional Amount Of Foreign Currency Cash Flow Hedge Derivatives NotionalAmountOfForeignCurrencyCashFlowHedgeDerivatives	110400000	USD
CY2009Q4	us-gaap	Notional Amount Of Foreign Currency Cash Flow Hedge Derivatives NotionalAmountOfForeignCurrencyCashFlowHedgeDerivatives	59400000	USD
CY2010	dei	Entity Central Index Key EntityCentralIndexKey	0001043604
CY2010Q4	us-gaap	Common Stock Value Outstanding CommonStockValueOutstanding	5000	USD
CY2009Q4	us-gaap	Common Stock Value Outstanding CommonStockValueOutstanding	5000	USD
CY2009Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	170245000	USD
CY2010Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	103823000	USD
CY2010	jnpr	Sale Of Receivable SaleOfReceivable	637500000	USD
CY2009	jnpr	Sale Of Receivable SaleOfReceivable	449800000	USD
CY2009Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	322800000	USD
CY2010Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	221800000	USD
CY2009Q4	us-gaap	Deferred Revenue Noncurrent DeferredRevenueNoncurrent	181937000	USD
CY2010Q4	us-gaap	Deferred Revenue Noncurrent DeferredRevenueNoncurrent	224165000	USD
CY2008	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Compensation Cost ShareBasedCompensationArrangementByShareBasedPaymentAwardCompensationCost	108100000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Compensation Cost ShareBasedCompensationArrangementByShareBasedPaymentAwardCompensationCost	182000000	USD
CY2009	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Compensation Cost ShareBasedCompensationArrangementByShareBasedPaymentAwardCompensationCost	139700000	USD
CY2009Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	6200000	USD
CY2010Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	14100000	USD
CY2010	jnpr	Foreign Currency Translation Gains Losses ForeignCurrencyTranslationGainsLosses	0	USD
CY2009	jnpr	Foreign Currency Translation Gains Losses ForeignCurrencyTranslationGainsLosses	0	USD
CY2008	jnpr	Foreign Currency Translation Gains Losses ForeignCurrencyTranslationGainsLosses	0	USD
CY2010Q4	jnpr	Restricted Stock Outstanding Subject To Repurchase From Acquisitions RestrictedStockOutstandingSubjectToRepurchaseFromAcquisitions	0	shares
CY2009Q4	jnpr	Restricted Stock Outstanding Subject To Repurchase From Acquisitions RestrictedStockOutstandingSubjectToRepurchaseFromAcquisitions	0	shares
CY2008Q4	jnpr	Restricted Stock Outstanding Subject To Repurchase From Acquisitions RestrictedStockOutstandingSubjectToRepurchaseFromAcquisitions	0	shares
CY2008	jnpr	Increasedecreaseinaccrued Warranty IncreasedecreaseinaccruedWarranty	2640000	USD
CY2009	jnpr	Increasedecreaseinaccrued Warranty IncreasedecreaseinaccruedWarranty	-1891000	USD
CY2010	jnpr	Increasedecreaseinaccrued Warranty IncreasedecreaseinaccruedWarranty	-2268000	USD
CY2009	jnpr	Interest Income And Expense Net InterestIncomeAndExpenseNet	5828000	USD
CY2008	jnpr	Interest Income And Expense Net InterestIncomeAndExpenseNet	49649000	USD
CY2010	jnpr	Interest Income And Expense Net InterestIncomeAndExpenseNet	1833000	USD
CY2010Q4	jnpr	Available For Sale Investments And Trading Securities Fair Value AvailableForSaleInvestmentsAndTradingSecuritiesFairValue	1009700000	USD
CY2009Q4	jnpr	Available For Sale Investments And Trading Securities Fair Value AvailableForSaleInvestmentsAndTradingSecuritiesFairValue	1054000000	USD
CY2009	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-1800000	USD
CY2010	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	1000000	USD
CY2008	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	0	USD
CY2009	us-gaap	Restructuring Charges RestructuringCharges	19463000	USD
CY2008	us-gaap	Restructuring Charges RestructuringCharges	0	USD
CY2010	us-gaap	Restructuring Charges RestructuringCharges	10805000	USD
CY2009Q2	us-gaap	Restructuring Charges RestructuringCharges	7500000	USD
CY2009Q3	us-gaap	Restructuring Charges RestructuringCharges	4500000	USD
CY2009Q1	us-gaap	Restructuring Charges RestructuringCharges	4200000	USD
CY2009Q4	us-gaap	Restructuring Charges RestructuringCharges	3200000	USD
CY2010Q4	us-gaap	Restructuring Charges RestructuringCharges	2300000	USD
CY2010Q3	us-gaap	Restructuring Charges RestructuringCharges	200000	USD
CY2010Q2	us-gaap	Restructuring Charges RestructuringCharges	200000	USD
CY2010Q1	us-gaap	Restructuring Charges RestructuringCharges	8100000	USD
CY2010Q4	jnpr	Estimated Incremental Tax Liability Excluding Interest And Penalties Related To Nopa EstimatedIncrementalTaxLiabilityExcludingInterestAndPenaltiesRelatedToNopa	807000000	USD
CY2009Q1	jnpr	Number Of Shares Available For Future Issuance1999 Espp Plan NumberOfSharesAvailableForFutureIssuance1999EsppPlan	0	shares
CY2010Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	201765000	USD
CY2009Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	142526000	USD
CY2010	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	84000	USD
CY2009	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	1100000	USD
CY2008	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-900000	USD
CY2010	us-gaap	Operating Leases Rent Expense Minimum Rentals OperatingLeasesRentExpenseMinimumRentals	55900000	USD
CY2009	us-gaap	Operating Leases Rent Expense Minimum Rentals OperatingLeasesRentExpenseMinimumRentals	56600000	USD
CY2008	us-gaap	Operating Leases Rent Expense Minimum Rentals OperatingLeasesRentExpenseMinimumRentals	58000000	USD
CY2010	us-gaap	Available For Sale Securities Gross Unrealized Gains AvailableForSaleSecuritiesGrossUnrealizedGains	-3100000	USD
CY2009	us-gaap	Available For Sale Securities Gross Unrealized Gains AvailableForSaleSecuritiesGrossUnrealizedGains	-3000000	USD
CY2010	us-gaap	Trading Securities Unrealized Holding Loss TradingSecuritiesUnrealizedHoldingLoss	0	USD
CY2009	us-gaap	Trading Securities Unrealized Holding Loss TradingSecuritiesUnrealizedHoldingLoss	0	USD
CY2010	jnpr	Available For Sale Investments And Trading Securities Unrealized Gain AvailableForSaleInvestmentsAndTradingSecuritiesUnrealizedGain	-3100000	USD
CY2009	jnpr	Available For Sale Investments And Trading Securities Unrealized Gain AvailableForSaleInvestmentsAndTradingSecuritiesUnrealizedGain	-3000000	USD
CY2010	jnpr	Gross Unrealized Gains No Contractual Maturity GrossUnrealizedGainsNoContractualMaturity	0	USD
CY2009	jnpr	Gross Unrealized Gains No Contractual Maturity GrossUnrealizedGainsNoContractualMaturity	0	USD
CY2010Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.00001	USD
CY2009Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.00001	USD
CY2009Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	37800000	USD
CY2010Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	58500000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	531200000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	538700000	USD
CY2010	jnpr	Total Management Operating Income TotalManagementOperatingIncome	981739000	USD
CY2009	jnpr	Total Management Operating Income TotalManagementOperatingIncome	668408000	USD
CY2008	jnpr	Total Management Operating Income TotalManagementOperatingIncome	863854000	USD
CY2010Q4	jnpr	Five Year Data Center Hosting Agreement Amount FiveYearDataCenterHostingAgreementAmount	13200000	USD
CY2010	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	1974000	shares
CY2009	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	3221000	shares
CY2008	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	1590000	shares
CY2008	us-gaap	Interest Paid Net InterestPaidNet	5224000	USD
CY2009	us-gaap	Interest Paid Net InterestPaidNet	5417000	USD
CY2010	us-gaap	Interest Paid Net InterestPaidNet	8799000	USD
CY2010	us-gaap	Future Amortization Expense Year Five FutureAmortizationExpenseYearFive	16600000	USD
CY2009	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	4400000	USD
CY2010	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	-3000000	USD
CY2010	jnpr	Gross Unrealized Losses Due Within One Year GrossUnrealizedLossesDueWithinOneYear	0	USD
CY2009	jnpr	Gross Unrealized Losses Due Within One Year GrossUnrealizedLossesDueWithinOneYear	0	USD
CY2008	us-gaap	Gross Profit GrossProfit	2435483000	USD
CY2010	us-gaap	Gross Profit GrossProfit	2741747000	USD
CY2009	us-gaap	Gross Profit GrossProfit	2183203000	USD
CY2009Q2	us-gaap	Gross Profit GrossProfit	506400000	USD
CY2009Q3	us-gaap	Gross Profit GrossProfit	543300000	USD
CY2009Q4	us-gaap	Gross Profit GrossProfit	631200000	USD
CY2009Q1	us-gaap	Gross Profit GrossProfit	502300000	USD
CY2010Q2	us-gaap	Gross Profit GrossProfit	659900000	USD
CY2010Q1	us-gaap	Gross Profit GrossProfit	612000000	USD
CY2010Q3	us-gaap	Gross Profit GrossProfit	677800000	USD
CY2008	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	363700000	USD
CY2010	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	370600000	USD
CY2009Q4	us-gaap	Deferred Revenue DeferredRevenue	753589000	USD
CY2010	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	78071000	USD
CY2008	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	1761000	USD
CY2009	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	16079000	USD
CY2010Q4	us-gaap	Gross Profit GrossProfit	792000000	USD
CY2010	jnpr	Fair Market Value On Date Of Grant For Rsus And Psas Issued At Discount Maximum Percentage FairMarketValueOnDateOfGrantForRsusAndPsasIssuedAtDiscountMaximumPercentage	1	pure
CY2009	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	398435000	USD
CY2010	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1086514000	USD
CY2008	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	369114000	USD
CY2008Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	6700000	shares
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	9100000	shares
CY2007Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	6300000	shares
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	14200000	shares
CY2010Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1251000	USD
CY2009Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1433000	USD
CY2010	jnpr	Gross Unrealized Losses Due Between One And Five Year GrossUnrealizedLossesDueBetweenOneAndFiveYear	-500000	USD
CY2009	jnpr	Gross Unrealized Losses Due Between One And Five Year GrossUnrealizedLossesDueBetweenOneAndFiveYear	-700000	USD
CY2010	jnpr	Warranty Period Hardware WarrantyPeriodHardware	1	pure
CY2010	jnpr	Stock Repurchased And Retired Related To Net Issuances Shares StockRepurchasedAndRetiredRelatedToNetIssuancesShares	75000	shares
CY2010Q4	jnpr	Unrealized Losses On Restricted Investments UnrealizedLossesOnRestrictedInvestments	0	USD
CY2009Q4	jnpr	Unrealized Losses On Restricted Investments UnrealizedLossesOnRestrictedInvestments	0	USD
CY2010	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations During Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsDuringPeriodWeightedAverageExercisePrice	61.48
CY2008	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations During Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsDuringPeriodWeightedAverageExercisePrice	28.75
CY2009	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations During Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsDuringPeriodWeightedAverageExercisePrice	34.91
CY2010	dei	Entity Registrant Name EntityRegistrantName	JUNIPER NETWORKS INC
CY2010	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	129292000	USD
CY2009	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	8520000	USD
CY2008	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	539000	USD
CY2009	jnpr	Reclassified Sales And Marketing Expense ReclassifiedSalesAndMarketingExpense	25100000	USD
CY2008	jnpr	Reclassified Sales And Marketing Expense ReclassifiedSalesAndMarketingExpense	29100000	USD
CY2009	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	50100000	USD
CY2010Q4	us-gaap	Deferred Revenue DeferredRevenue	884429000	USD
CY2010Q4	jnpr	Vesting Period For Restricted Shares VestingPeriodForRestrictedShares	2	pure
CY2009Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	466900000	USD
CY2010Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	571527000	USD
CY2009	us-gaap	Impairment Of Intangible Assets Finitelived ImpairmentOfIntangibleAssetsFinitelived	0	USD
CY2010	us-gaap	Impairment Of Intangible Assets Finitelived ImpairmentOfIntangibleAssetsFinitelived	0	USD
CY2010Q4	us-gaap	Business Acquisition Cost Of Acquired Entity Purchase Price BusinessAcquisitionCostOfAcquiredEntityPurchasePrice	394500000	USD
CY2010	jnpr	Maximum Rsu And Psa Vesting Period Based On Continued Employment MaximumRsuAndPsaVestingPeriodBasedOnContinuedEmployment	4	pure
CY2010	us-gaap	Payments For Legal Settlements PaymentsForLegalSettlements	169330000	USD
CY2009	us-gaap	Payments For Legal Settlements PaymentsForLegalSettlements	-169330000	USD
CY2008	us-gaap	Payments For Legal Settlements PaymentsForLegalSettlements	0	USD
CY2010	us-gaap	Property Plant And Equipment Useful Life Maximum PropertyPlantAndEquipmentUsefulLifeMaximum	5	pure
CY2009	jnpr	Amortization Of Purchased Intangible Assets AmortizationOfPurchasedIntangibleAssets	15428000	USD
CY2010	jnpr	Amortization Of Purchased Intangible Assets AmortizationOfPurchasedIntangibleAssets	8618000	USD
CY2008	jnpr	Amortization Of Purchased Intangible Assets AmortizationOfPurchasedIntangibleAssets	48984000	USD
CY2009Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	10000000	shares
CY2010Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	10000000	shares
CY2010	dei	Document Type DocumentType	10-K
CY2010	us-gaap	Other Tax Expense Benefit OtherTaxExpenseBenefit	58000000	USD
CY2009	us-gaap	Other Tax Expense Benefit OtherTaxExpenseBenefit	1000000	USD
CY2008	us-gaap	Other Tax Expense Benefit OtherTaxExpenseBenefit	31200000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	75600000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	68300000	USD
CY2010Q4	jnpr	Available For Sale Investments And Trading Securities Amortized Cost AvailableForSaleInvestmentsAndTradingSecuritiesAmortizedCost	1007100000	USD
CY2009Q4	jnpr	Available For Sale Investments And Trading Securities Amortized Cost AvailableForSaleInvestmentsAndTradingSecuritiesAmortizedCost	1051700000	USD
CY2008	jnpr	Effectiveincometaxratereconciliationstateandlocalrate Effectiveincometaxratereconciliationstateandlocalrate	-16600000	USD
CY2010	jnpr	Effectiveincometaxratereconciliationstateandlocalrate Effectiveincometaxratereconciliationstateandlocalrate	-6200000	USD
CY2009	jnpr	Effectiveincometaxratereconciliationstateandlocalrate Effectiveincometaxratereconciliationstateandlocalrate	1600000	USD
CY2010Q4	us-gaap	Business Combination Consideration Transferred BusinessCombinationConsiderationTransferred	394500000	USD
CY2010Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	113903000	USD
CY2009Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	13834000	USD
CY2009Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	148300000	USD
CY2010Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	175100000	USD
CY2009Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1604723000	USD
CY2010Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1811887000	USD
CY2008Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2019084000	USD
CY2007Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1716110000	USD
CY2009	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	28682000	USD
CY2008	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	50211000	USD
CY2010	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	129199000	USD
CY2010	jnpr	Contractual Support Period ContractualSupportPeriod	one year or less
CY2010Q4	us-gaap	Liabilities Current LiabilitiesCurrent	1471976000	USD
CY2009Q4	us-gaap	Liabilities Current LiabilitiesCurrent	1375785000	USD
CY2010Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	448903000	USD
CY2009Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	448934000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	16400000	shares
CY2010Q4	jnpr	Total Investments In Unrealized Loss Position TotalInvestmentsInUnrealizedLossPosition	73	pure
CY2009Q4	jnpr	Total Investments In Unrealized Loss Position TotalInvestmentsInUnrealizedLossPosition	52	pure
CY2010	jnpr	Number Of Years Monthly Vesting Occurs For Director Option Grants NumberOfYearsMonthlyVestingOccursForDirectorOptionGrants	3	pure
CY2010	jnpr	Employee Contribution Matched In Percent EmployeeContributionMatchedInPercent	0.25	pure
CY2008	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	119450000	USD
CY2009	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	164207000	USD
CY2010	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	451039000	USD
CY2010	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	1624400000	USD
CY2009	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	683800000	USD
CY2008	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	499400000	USD
CY2009	jnpr	Restricted Cash Distribution For Settlement Of Acquisition RestrictedCashDistributionForSettlementOfAcquisition	1000000	USD
CY2010	jnpr	Restricted Cash Distribution For Settlement Of Acquisition RestrictedCashDistributionForSettlementOfAcquisition	196500000	USD
CY2010Q4	us-gaap	Available For Sale Securities Fair Value Disclosure AvailableForSaleSecuritiesFairValueDisclosure	1001600000	USD
CY2009Q4	us-gaap	Available For Sale Securities Fair Value Disclosure AvailableForSaleSecuritiesFairValueDisclosure	1049300000	USD
CY2009Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	519341000	shares
CY2010Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	525378000	shares
CY2008Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	526752000	shares
CY2007Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	522815000	shares
CY2010	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	64000000	USD
CY2008	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	14300000	USD
CY2009	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	7100000	USD
CY2010	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-8400000	USD
CY2009	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	123800000	USD
CY2008	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	96600000	USD
CY2008	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	495253000	USD
CY2010	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	618555000	USD
CY2009	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	119840000	USD
CY2010	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Exercisable Options Weighted Average Exercise Price ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice	20.96
CY2008	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	0	USD
CY2010	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	0	USD
CY2009	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	0	USD
CY2010Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	26800000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	25800000	USD
CY2009Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2010Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2010Q4	jnpr	Receivables From Sale Of Receivables ReceivablesFromSaleOfReceivables	127400000	USD
CY2009Q4	jnpr	Receivables From Sale Of Receivables ReceivablesFromSaleOfReceivables	89800000	USD
CY2008	us-gaap	Operating Income Loss OperatingIncomeLoss	694974000	USD
CY2009	us-gaap	Operating Income Loss OperatingIncomeLoss	310695000	USD
CY2010	us-gaap	Operating Income Loss OperatingIncomeLoss	767584000	USD
CY2009Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	482200000	USD
CY2009Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	81200000	USD
CY2009Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	5800000	USD
CY2009Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	95700000	USD
CY2009Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	128000000	USD
CY2010Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	160300000	USD
CY2010Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	226800000	USD
CY2010Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	195500000	USD
CY2010Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	185000000	USD
CY2010	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	6342000	USD
CY2009	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
CY2008	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
CY2010Q3	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	1500000	USD
CY2010Q4	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	4300000	USD
CY2010Q1	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
CY2010Q2	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	500000	USD
CY2008	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	17900000	USD
CY2009	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	12700000	USD
CY2010	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	13900000	USD
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber	47000000	shares
CY2009	us-gaap	Advertising Expense AdvertisingExpense	11400000	USD
CY2008	us-gaap	Advertising Expense AdvertisingExpense	5000000	USD
CY2010	us-gaap	Advertising Expense AdvertisingExpense	17100000	USD
CY2010	us-gaap	Standard Product Warranty Accrual Payments StandardProductWarrantyAccrualPayments	49200000	USD
CY2009	us-gaap	Standard Product Warranty Accrual Payments StandardProductWarrantyAccrualPayments	43200000	USD
CY2010	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	9400000	USD
CY2009	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	71300000	USD
CY2010	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Remaining Contractual Term ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm	4.1	pure
CY2010Q4	us-gaap	Notional Amount Of Foreign Currency Derivatives NotionalAmountOfForeignCurrencyDerivatives	184800000	USD
CY2009Q4	us-gaap	Notional Amount Of Foreign Currency Derivatives NotionalAmountOfForeignCurrencyDerivatives	114100000	USD
CY2010Q4	jnpr	Amount Of Restricted Investments Measured At Fair Value Included In Balance Of Money Market Funds AmountOfRestrictedInvestmentsMeasuredAtFairValueIncludedInBalanceOfMoneyMarketFunds	114300000	USD
CY2009	jnpr	Restricted Stock From Acquisitions Repurchased During Year RestrictedStockFromAcquisitionsRepurchasedDuringYear	0	shares
CY2008	jnpr	Restricted Stock From Acquisitions Repurchased During Year RestrictedStockFromAcquisitionsRepurchasedDuringYear	0	shares
CY2010	jnpr	Restricted Stock From Acquisitions Repurchased During Year RestrictedStockFromAcquisitionsRepurchasedDuringYear	0	shares
CY2010	us-gaap	Share Based Goods And Nonemployee Services Transaction Quantity Of Securities Issued ShareBasedGoodsAndNonemployeeServicesTransactionQuantityOfSecuritiesIssued	50000	shares
CY2010Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	533500000	USD
CY2010	jnpr	Share Based Compensation Arrangement By Share Based Payment Awards Options Assumed In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardsOptionsAssumedInPeriodWeightedAverageExercisePrice	31.65
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Other Share Increase Decrease ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherShareIncreaseDecrease	-2300000	shares
CY2009	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Other Share Increase Decrease ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherShareIncreaseDecrease	-2300000	shares
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	2200000	shares
CY2009Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	9060089000	USD
CY2010Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	9717783000	USD
CY2009	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses	700000	USD
CY2010	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses	-500000	USD
CY2009	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	11276000	USD
CY2010	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	12424000	USD
CY2008	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	8094000	USD
CY2008	us-gaap	Net Income Loss NetIncomeLoss	511749000	USD
CY2009	us-gaap	Net Income Loss NetIncomeLoss	116999000	USD
CY2010	us-gaap	Net Income Loss NetIncomeLoss	618402000	USD
CY2009Q4	us-gaap	Net Income Loss NetIncomeLoss	22900000	USD
CY2009Q1	us-gaap	Net Income Loss NetIncomeLoss	-4400000	USD
CY2008	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Other Share Increase Decrease ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherShareIncreaseDecrease	-2400000	shares
CY2009Q2	us-gaap	Net Income Loss NetIncomeLoss	14800000	USD
CY2009Q3	us-gaap	Net Income Loss NetIncomeLoss	83800000	USD
CY2010Q3	us-gaap	Net Income Loss NetIncomeLoss	134500000	USD
CY2010Q2	us-gaap	Net Income Loss NetIncomeLoss	130500000	USD
CY2010Q4	us-gaap	Net Income Loss NetIncomeLoss	190200000	USD
CY2010Q1	us-gaap	Net Income Loss NetIncomeLoss	163100000	USD
CY2010	jnpr	Maturities Of Cash Flow Hedge Derivatives MaturitiesOfCashFlowHedgeDerivatives	less than one year
CY2009	us-gaap	Restructuring Reserve Accrual Adjustment RestructuringReserveAccrualAdjustment	-1800000	USD
CY2010	us-gaap	Restructuring Reserve Accrual Adjustment RestructuringReserveAccrualAdjustment	-4300000	USD
CY2010Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	25000000	USD
CY2009Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	34936000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	260300000	USD
CY2009	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	83600000	USD
CY2008	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	66700000	USD
CY2010	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-532750000	USD
CY2008	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-149812000	USD
CY2009	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-948300000	USD
CY2010Q4	us-gaap	Indefinite Lived Intangible Assets IndefiniteLivedIntangibleAssets	0	USD
CY2010	us-gaap	Payments To Minority Shareholders PaymentsToMinorityShareholders	3000000	USD
CY2009	us-gaap	Payments To Minority Shareholders PaymentsToMinorityShareholders	-4400000	USD
CY2008	us-gaap	Payments To Minority Shareholders PaymentsToMinorityShareholders	0	USD
CY2010Q4	jnpr	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	448903000	USD
CY2010	us-gaap	Cost Of Revenue CostOfRevenue	1351519000	USD
CY2009	us-gaap	Cost Of Revenue CostOfRevenue	1132709000	USD
CY2008	us-gaap	Cost Of Revenue CostOfRevenue	1136893000	USD
CY2009Q1	us-gaap	Cost Of Revenue CostOfRevenue	261800000	USD
CY2009Q4	us-gaap	Cost Of Revenue CostOfRevenue	310300000	USD
CY2009Q2	us-gaap	Cost Of Revenue CostOfRevenue	280000000	USD
CY2009Q3	us-gaap	Cost Of Revenue CostOfRevenue	280600000	USD
CY2010Q2	us-gaap	Cost Of Revenue CostOfRevenue	318400000	USD
CY2010Q3	us-gaap	Cost Of Revenue CostOfRevenue	334600000	USD
CY2010Q1	us-gaap	Cost Of Revenue CostOfRevenue	300600000	USD
CY2010Q4	us-gaap	Cost Of Revenue CostOfRevenue	398000000	USD
CY2009	us-gaap	Cost Of Services CostOfServices	290987000	USD
CY2010	us-gaap	Cost Of Services CostOfServices	350654000	USD
CY2008	us-gaap	Cost Of Services CostOfServices	269298000	USD
CY2009Q1	us-gaap	Cost Of Services CostOfServices	68800000	USD
CY2009Q4	us-gaap	Cost Of Services CostOfServices	75500000	USD
CY2009Q2	us-gaap	Cost Of Services CostOfServices	72400000	USD
CY2009Q3	us-gaap	Cost Of Services CostOfServices	74300000	USD
CY2010Q1	us-gaap	Cost Of Services CostOfServices	78200000	USD
CY2010Q4	us-gaap	Cost Of Services CostOfServices	98300000	USD
CY2010Q2	us-gaap	Cost Of Services CostOfServices	86600000	USD
CY2010Q3	us-gaap	Cost Of Services CostOfServices	87600000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	2300000	shares
CY2008	jnpr	Cash Payment From Acquisition By Third Party CashPaymentFromAcquisitionByThirdParty	2100000	USD
CY2009	jnpr	Cash Payment From Acquisition By Third Party CashPaymentFromAcquisitionByThirdParty	300000	USD
CY2010	us-gaap	Other Noncash Expense OtherNoncashExpense	0	USD
CY2008	us-gaap	Other Noncash Expense OtherNoncashExpense	613000	USD
CY2009	us-gaap	Other Noncash Expense OtherNoncashExpense	0	USD
CY2007Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	66900000	shares
CY2008Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	73600000	shares
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	49400000	shares
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	67400000	shares
CY2010	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2008	us-gaap	Excess Tax Benefit From Share Based Compensation Financing Activities ExcessTaxBenefitFromShareBasedCompensationFinancingActivities	40182000	USD
CY2009	us-gaap	Excess Tax Benefit From Share Based Compensation Financing Activities ExcessTaxBenefitFromShareBasedCompensationFinancingActivities	3510000	USD
CY2010	us-gaap	Excess Tax Benefit From Share Based Compensation Financing Activities ExcessTaxBenefitFromShareBasedCompensationFinancingActivities	48500000	USD
CY2009Q4	jnpr	Cash Received From Financing Provider That Has Not Been Recognized As Revenue CashReceivedFromFinancingProviderThatHasNotBeenRecognizedAsRevenue	52600000	USD
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CY2010Q4	us-gaap	Recorded Unconditional Purchase Obligation RecordedUnconditionalPurchaseObligation	198600000	USD
CY2010	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	-5700000	USD
CY2008	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	0	USD
CY2009	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	-2300000	USD
CY2010	jnpr	Stock Repurchased And Retired During Period Under Repurchase Plans Shares StockRepurchasedAndRetiredDuringPeriodUnderRepurchasePlansShares	19700000	shares
CY2009	jnpr	Stock Repurchased And Retired During Period Under Repurchase Plans Shares StockRepurchasedAndRetiredDuringPeriodUnderRepurchasePlansShares	20700000	shares
CY2010	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	409395000	USD
CY2009	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	126284000	USD
CY2008	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	82608000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Other DeferredTaxAssetsTaxCreditCarryforwardsOther	66000000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Other DeferredTaxAssetsTaxCreditCarryforwardsOther	68200000	USD
CY2010	jnpr	Six Month Average Daily Closing Price SixMonthAverageDailyClosingPrice	6	pure
CY2010	jnpr	Stock Repurchased And Retired During Period Net Of Issuances Shares StockRepurchasedAndRetiredDuringPeriodNetOfIssuancesShares	100000	shares
CY2010	jnpr	Shares Repurchased And Retired Related To Net Issuances SharesRepurchasedAndRetiredRelatedToNetIssuances	1947000	USD
CY2010	jnpr	Investment In Publicly Held Company InvestmentInPubliclyHeldCompany	0	USD
CY2010Q4	jnpr	Acquired Finite And Indefinite Lived Intangible Assets Amount AcquiredFiniteAndIndefiniteLivedIntangibleAssetsAmount	116500000	USD
CY2009Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	211500000	USD
CY2010Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	280800000	USD
CY2009Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	176551000	USD
CY2010Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	256746000	USD
CY2009	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	21400000	USD
CY2008	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	35800000	USD
CY2010	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	1000000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Remaining Contractual Term ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm	3.5	pure
CY2010	jnpr	Additional Authorized Share Reserve Approved By Shareholders AdditionalAuthorizedShareReserveApprovedByShareholders	30000000	shares
CY2010Q4	jnpr	Trading Securities Amortized Cost TradingSecuritiesAmortizedCost	8100000	USD
CY2009Q4	jnpr	Trading Securities Amortized Cost TradingSecuritiesAmortizedCost	4700000	USD
CY2010	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	537916000	USD
CY2009	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	285379000	USD
CY2008	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	130237000	USD
CY2010	us-gaap	Trading Securities Unrealized Holding Gain TradingSecuritiesUnrealizedHoldingGain	0	USD
CY2009	us-gaap	Trading Securities Unrealized Holding Gain TradingSecuritiesUnrealizedHoldingGain	0	USD
CY2009	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	262000000	USD
CY2010	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	407600000	USD
CY2008	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	365200000	USD
CY2009Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	322800000	USD
CY2010Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	256800000	USD
CY2010Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	535200000	USD
CY2009Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	483500000	USD
CY2010	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	127894000	USD
CY2009	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	163326000	USD
CY2008	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	76994000	USD
CY2010Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	8100000	USD
CY2009Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	10100000	USD
CY2009	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriod	-8600000	shares
CY2008	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriod	-5700000	shares
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriod	-21600000	shares
CY2010	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses	0	USD
CY2010	us-gaap	Commitments And Contingencies2009 CommitmentsAndContingencies2009
CY2009	us-gaap	Commitments And Contingencies2009 CommitmentsAndContingencies2009
CY2008	us-gaap	Litigation Settlement Expense LitigationSettlementExpense	9000000	USD
CY2009	us-gaap	Litigation Settlement Expense LitigationSettlementExpense	182331000	USD
CY2010	us-gaap	Litigation Settlement Expense LitigationSettlementExpense	0	USD
CY2009Q3	us-gaap	Litigation Settlement Expense LitigationSettlementExpense	1000000	USD
CY2009Q2	us-gaap	Litigation Settlement Expense LitigationSettlementExpense	0	USD
CY2009Q1	us-gaap	Litigation Settlement Expense LitigationSettlementExpense	0	USD
CY2009Q4	us-gaap	Litigation Settlement Expense LitigationSettlementExpense	181300000	USD
CY2009	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	3510000	USD
CY2008	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	40182000	USD
CY2010	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	48500000	USD
CY2010Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	18900000	USD
CY2009Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	23500000	USD
CY2008Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	8700000	USD
CY2008	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedInPeriodTotalFairValue	70300000	USD
CY2010	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedInPeriodTotalFairValue	83200000	USD
CY2009	jnpr	Share Based Compensation Arrangement By Share Based Payment Award Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedInPeriodTotalFairValue	88900000	USD
CY2009	jnpr	Increase In Restricted Cash IncreaseInRestrictedCash	11300000	USD
CY2010	jnpr	Increase In Restricted Cash IncreaseInRestrictedCash	261900000	USD
CY2010	jnpr	Increase In Revenue Due To Products Booked And Shipped IncreaseInRevenueDueToProductsBookedAndShipped	183000000	USD
CY2009Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	25100000	USD
CY2010Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	47100000	USD
CY2009	us-gaap	Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures	1432000	shares
CY2010	us-gaap	Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures	2224000	shares
CY2008	us-gaap	Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures	1904000	shares
CY2010	jnpr	Value Shares Assumed In Connection With Business Acquisition ValueSharesAssumedInConnectionWithBusinessAcquisition	2355000	USD
CY2011Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	534922000	shares
CY2010	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	16356000	shares
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CY2009	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	10412000	shares
CY2009	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	8651000	shares
CY2010	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	21568000	shares
CY2008	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	5701000	shares
CY2010Q4	jnpr	Unrecognized Compensation Cost Related To Unvested Restricted Stock Units UnrecognizedCompensationCostRelatedToUnvestedRestrictedStockUnits	151200000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	135700000	USD
CY2009Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	206900000	USD
CY2010Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	7900000	USD
CY2010Q4	jnpr	Unrealized Gains On Restricted Investments UnrealizedGainsOnRestrictedInvestments	0	USD
CY2010Q1	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	43100000	USD
CY2010Q4	us-gaap	Assets Assets	8467851000	USD
CY2009Q4	us-gaap	Assets Assets	7590263000	USD
CY2010	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	0	USD
CY2009	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	0	USD
CY2008	us-gaap	Marketable Securities Realized Gain Loss MarketableSecuritiesRealizedGainLoss	0	USD
CY2010Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	8100000	USD
CY2009Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	10100000	USD
CY2010	jnpr	Minimum Rsu And Psa Vesting Period Based On Continued Employment MinimumRsuAndPsaVestingPeriodBasedOnContinuedEmployment	3	pure
CY2009Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Foreign DeferredTaxAssetsTaxCreditCarryforwardsForeign	34100000	USD
CY2010Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Foreign DeferredTaxAssetsTaxCreditCarryforwardsForeign	40300000	USD
CY2009Q4	us-gaap	Restructuring Reserve RestructuringReserve	9400000	USD
CY2008Q4	us-gaap	Restructuring Reserve RestructuringReserve	0	USD
CY2010Q4	us-gaap	Restructuring Reserve RestructuringReserve	7900000	USD
CY2010	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	177859000	USD
CY2008	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	144837000	USD
CY2009	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	159459000	USD
CY2009Q4	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	41200000	USD
CY2009Q3	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	39900000	USD
CY2009Q2	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	39200000	USD
CY2009Q1	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	39200000	USD
CY2010Q3	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	43800000	USD
CY2010Q2	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	45900000	USD
CY2010Q4	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	45100000	USD
CY2010	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	14000000	shares
CY2009	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	38900000	shares
CY2009	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	11900000	USD
CY2010	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	13200000	USD
CY2008	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	10700000	USD
CY2010	jnpr	Vested And Expected To Vest Restricted Stock Units And Performance Share Awards Weighted Average Remaining Contractual Term VestedAndExpectedToVestRestrictedStockUnitsAndPerformanceShareAwardsWeightedAverageRemainingContractualTerm	1.6	pure
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Other Increases Decreases In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOtherIncreasesDecreasesInPeriod	500000	shares
CY2010	jnpr	Effectivetaxratereconciliationnondeductiblesharebasedexpense Effectivetaxratereconciliationnondeductiblesharebasedexpense	40200000	USD
CY2009	jnpr	Effectivetaxratereconciliationnondeductiblesharebasedexpense Effectivetaxratereconciliationnondeductiblesharebasedexpense	-62100000	USD
CY2008	jnpr	Effectivetaxratereconciliationnondeductiblesharebasedexpense Effectivetaxratereconciliationnondeductiblesharebasedexpense	-2400000	USD
CY2010	jnpr	One Time Recognized Tax Benefit OneTimeRecognizedTaxBenefit	73400000	USD
CY2010	dei	Document Period End Date DocumentPeriodEndDate	2010-12-31
CY2010	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	2754000	USD
CY2008	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	0	USD
CY2009	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	0	USD
CY2010	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	41829000	USD
CY2009	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	39164000	USD
CY2008	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	35879000	USD
CY2010Q4	jnpr	Three Year Software Subscription Agreement Amount ThreeYearSoftwareSubscriptionAgreementAmount	7700000	USD
CY2010Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2009Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2010Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	100200000	USD
CY2009	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.22
CY2008	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.93
CY2010	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.15
CY2009Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.04
CY2009Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.01
CY2009Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.16
CY2009Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.03
CY2010Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.3
CY2010Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.24
CY2010Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.25
CY2010Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.35
CY2009	us-gaap	Profit Loss ProfitLoss	115228000	USD
CY2010	us-gaap	Profit Loss ProfitLoss	619373000	USD
CY2008	us-gaap	Profit Loss ProfitLoss	511749000	USD
CY2009Q1	us-gaap	Profit Loss ProfitLoss	-4400000	USD
CY2009Q2	us-gaap	Profit Loss ProfitLoss	14800000	USD
CY2009Q4	us-gaap	Profit Loss ProfitLoss	21100000	USD
CY2009Q3	us-gaap	Profit Loss ProfitLoss	83800000	USD
CY2010Q4	us-gaap	Profit Loss ProfitLoss	190100000	USD
CY2010Q2	us-gaap	Profit Loss ProfitLoss	130300000	USD
CY2010Q3	us-gaap	Profit Loss ProfitLoss	134300000	USD
CY2010Q1	us-gaap	Profit Loss ProfitLoss	164600000	USD
CY2009	jnpr	Common Stock Value From Acquisition Of Publicly Traded Company CommonStockValueFromAcquisitionOfPubliclyTradedCompany	1000000	USD
CY2010	us-gaap	Other Comprehensive Income Available For Sale Securities Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecrease	-317000	USD
CY2009	us-gaap	Other Comprehensive Income Available For Sale Securities Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecrease	-2757000	USD
CY2008	us-gaap	Other Comprehensive Income Available For Sale Securities Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecrease	2547000	USD
CY2010Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6608800000	USD
CY2009Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	5824765000	USD
CY2007Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	5353860000	USD
CY2008Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	5901405000	USD
CY2009Q2	us-gaap	Sales Revenue Net SalesRevenueNet	786400000	USD
CY2009Q1	us-gaap	Sales Revenue Net SalesRevenueNet	764100000	USD
CY2009Q3	us-gaap	Sales Revenue Net SalesRevenueNet	823900000	USD
CY2010Q4	us-gaap	Sales Revenue Net SalesRevenueNet	1190000000	USD
CY2009Q1	us-gaap	Cost Of Goods Sold CostOfGoodsSold	193000000	USD
CY2009Q2	us-gaap	Cost Of Goods Sold CostOfGoodsSold	207600000	USD
CY2009Q3	us-gaap	Cost Of Goods Sold CostOfGoodsSold	206300000	USD
CY2010Q1	us-gaap	Cost Of Goods Sold CostOfGoodsSold	222400000	USD
CY2010Q4	jnpr	Vested And Expected To Vest Restricted Stock Units And Performance Share Awards Aggregate Intrinsic Value VestedAndExpectedToVestRestrictedStockUnitsAndPerformanceShareAwardsAggregateIntrinsicValue	448200000	USD
CY2010	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Lower Range Limit ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit	0.33
CY2009	us-gaap	Adjustments To Additional Paid In Capital Tax Effect From Share Based Compensation AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation	-50299000	USD
CY2008	us-gaap	Adjustments To Additional Paid In Capital Tax Effect From Share Based Compensation AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation	31164000	USD
CY2010	us-gaap	Adjustments To Additional Paid In Capital Tax Effect From Share Based Compensation AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation	101549000	USD
CY2009	us-gaap	Sales Revenue Net SalesRevenueNet	3315912000	USD
CY2008	us-gaap	Sales Revenue Net SalesRevenueNet	3572376000	USD
CY2010	us-gaap	Sales Revenue Net SalesRevenueNet	4093266000	USD
CY2009Q4	us-gaap	Sales Revenue Net SalesRevenueNet	941500000	USD
CY2010Q1	us-gaap	Sales Revenue Net SalesRevenueNet	912600000	USD
CY2010Q3	us-gaap	Sales Revenue Net SalesRevenueNet	1012400000	USD
CY2010Q2	us-gaap	Sales Revenue Net SalesRevenueNet	978300000	USD
CY2009	us-gaap	Cost Of Goods Sold CostOfGoodsSold	841722000	USD
CY2010	us-gaap	Cost Of Goods Sold CostOfGoodsSold	1000865000	USD
CY2008	us-gaap	Cost Of Goods Sold CostOfGoodsSold	867595000	USD
CY2009Q4	us-gaap	Cost Of Goods Sold CostOfGoodsSold	234800000	USD
CY2010Q2	us-gaap	Cost Of Goods Sold CostOfGoodsSold	231800000	USD
CY2010Q4	us-gaap	Cost Of Goods Sold CostOfGoodsSold	299700000	USD
CY2010Q3	us-gaap	Cost Of Goods Sold CostOfGoodsSold	247000000	USD
CY2009Q4	jnpr	Unrealized Gains On Restricted Investments UnrealizedGainsOnRestrictedInvestments	0	USD
CY2010Q4	jnpr	Estimated Deferred Tax Liability Cumulative Indefinitely Invested Undistributed Earnings EstimatedDeferredTaxLiabilityCumulativeIndefinitelyInvestedUndistributedEarnings	367900000	USD
CY2009	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses	700000	USD
CY2010	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses	-500000	USD
CY2010Q4	us-gaap	Available For Sale Securities Amortized Cost AvailableForSaleSecuritiesAmortizedCost	999000000	USD
CY2009Q4	us-gaap	Available For Sale Securities Amortized Cost AvailableForSaleSecuritiesAmortizedCost	1047000000	USD

Files In Submission

Name	View Source	Status
0001445305-11-000332-index-headers.html	Edgar Link	pending
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$JNPR
JUNIPER NETWORKS INC Stock $jnpr

2009 Q4 Form 10-K Financial Statement

#000144530511000332 Filed on February 25, 2011

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$JNPR JUNIPER NETWORKS INC Stock $jnpr

2009 Q4 Form 10-K Financial Statement

#000144530511000332 Filed on February 25, 2011

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$JNPR
JUNIPER NETWORKS INC Stock $jnpr