$TTEK
TETRA TECH INC Stock $ttek

$ttek Overview Financials Valuation SEC Filings Company Website

2017 Q3 Form 10-K Financial Statement

#000083164117000022 Filed on November 20, 2017

Income Statement

Concept	2017 Q3	2017 Q2	2017 Q1
Revenue	$685.5M	$663.8M	$668.9M
YoY Change		-0.46%	6.61%
Cost Of Revenue	$408.2M	$431.0M	$408.2M
YoY Change		4.21%	1.04%
Gross Profit	$90.25M	$81.00M	$81.36M
YoY Change		-4.82%	8.77%
Gross Profit Margin	13.16%	12.2%	12.16%
Selling, General & Admin	$44.40M	$45.20M	$41.50M
YoY Change		0.44%	2.72%
% of Gross Profit	49.2%	55.8%	51.01%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$5.300M	$5.800M	$11.19M
YoY Change		-53.23%	-3.53%
% of Gross Profit	5.87%	7.16%	13.75%
Operating Expenses	$44.40M	$38.00M	$41.50M
YoY Change		-15.37%	-1.66%
Operating Profit	$45.88M	$42.96M	$39.86M
YoY Change		9.9%	139.37%
Interest Expense	-$2.800M	-$3.100M	-$2.900M
YoY Change		19.23%	-32.56%
% of Operating Profit	-6.1%	-7.22%	-7.28%
Other Income/Expense, Net
YoY Change
Pretax Income	$43.09M	$39.86M	$36.95M
YoY Change		9.2%	197.96%
Income Tax	$13.11M	$12.99M	$10.36M
% Of Pretax Income	30.43%	32.59%	28.03%
Net Earnings	$29.98M	$26.87M	$26.59M
YoY Change		4.54%	618.62%
Net Earnings / Revenue	4.37%	4.05%	3.98%
Basic Earnings Per Share	$0.52	$0.47	$0.47
Diluted Earnings Per Share	$0.52	$0.46	$0.46
COMMON SHARES
Basic Shares Outstanding	57.18M shares	57.27M shares	57.10M shares
Diluted Shares Outstanding	58.16M shares	58.27M shares	58.15M shares

Balance Sheet

Concept	2017 Q3	2017 Q2	2017 Q1
SHORT-TERM ASSETS
Cash & Short-Term Investments	$138.8M	$171.3M	$127.0M
YoY Change		11.31%	11.7%
Cash & Equivalents	$138.8M	$171.3M	$127.0M
Short-Term Investments
Other Short-Term Assets	$56.90M	$50.10M	$53.70M
YoY Change		-3.65%	-4.96%
Inventory
Prepaid Expenses
Receivables	$692.8M	$679.2M	$718.1M
Other Receivables	$73.80M	$42.40M	$55.20M
Total Short-Term Assets	$962.3M	$943.1M	$954.0M
YoY Change		1.13%	9.09%
LONG-TERM ASSETS
Property, Plant & Equipment	$59.40M	$61.30M	$63.30M
YoY Change		-14.39%	-14.8%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$2.900M	$2.200M	$2.000M
YoY Change		15.79%	0.0%
Other Assets	$34.00M	$32.70M	$29.20M
YoY Change		14.74%	5.8%
Total Long-Term Assets	$857.4M	$855.3M	$846.4M
YoY Change		-2.99%	-3.64%
TOTAL ASSETS
Total Short-Term Assets	$962.3M	$943.1M	$954.0M
Total Long-Term Assets	$857.4M	$855.3M	$846.4M
Total Assets	$1.820B	$1.798B	$1.800B
YoY Change		-0.88%	2.71%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$156.6M	$143.5M	$136.2M
YoY Change		-7.48%	4.37%
Accrued Expenses	$116.6M	$117.1M	$92.30M
YoY Change		-0.68%	-4.75%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$15.50M	$18.60M	$15.50M
YoY Change		20.0%	-9.36%
Total Short-Term Liabilities	$489.0M	$465.3M	$428.6M
YoY Change		-9.4%	-9.9%
LONG-TERM LIABILITIES
Long-Term Debt	$310.3M	$326.9M	$372.7M
YoY Change		-6.39%	8.63%
Other Long-Term Liabilities	$51.70M	$57.10M	$62.80M
YoY Change		10.23%	20.31%
Total Long-Term Liabilities	$362.0M	$384.0M	$435.5M
YoY Change		-4.24%	10.17%
TOTAL LIABILITIES
Total Short-Term Liabilities	$489.0M	$465.3M	$428.6M
Total Long-Term Liabilities	$362.0M	$384.0M	$435.5M
Total Liabilities	$904.9M	$895.7M	$927.9M
YoY Change		-5.82%	2.7%
SHAREHOLDERS EQUITY
Retained Earnings
YoY Change
Common Stock
YoY Change
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$914.9M	$902.7M	$872.6M
YoY Change
Total Liabilities & Shareholders Equity	$1.820B	$1.798B	$1.800B
YoY Change		-0.88%	2.71%

Cashflow Statement

Concept	2017 Q3	2017 Q2	2017 Q1
OPERATING ACTIVITIES
Net Income	$29.98M	$26.87M	$26.59M
YoY Change		4.54%	618.62%
Depreciation, Depletion And Amortization	$5.300M	$5.800M	$11.19M
YoY Change		-53.23%	-3.53%
Cash From Operating Activities	$21.20M	$109.1M	-$58.75M
YoY Change		83.05%	-990.11%
INVESTING ACTIVITIES
Capital Expenditures	-$3.100M	-$1.900M	$2.031M
YoY Change		-53.66%	-175.22%
Acquisitions			$0.00
YoY Change
Other Investing Activities	$200.0K	-$7.900M	$200.0K
YoY Change		-459.09%	-100.24%
Cash From Investing Activities	-$3.000M	-$9.800M	-$1.808M
YoY Change		415.79%	-97.94%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net			$7.597M
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-52.40M	-55.80M	$28.94M
YoY Change		195.24%	-56.61%
NET CHANGE
Cash From Operating Activities	21.20M	109.1M	-$58.75M
Cash From Investing Activities	-3.000M	-9.800M	-$1.808M
Cash From Financing Activities	-52.40M	-55.80M	$28.94M
Net Change In Cash	-34.20M	43.50M	-$31.61M
YoY Change		12.11%	118.01%
FREE CASH FLOW
Cash From Operating Activities	$21.20M	$109.1M	-$58.75M
Capital Expenditures	-$3.100M	-$1.900M	$2.031M
Free Cash Flow	$24.30M	$111.0M	-$60.78M
YoY Change		74.25%	-753.53%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2017	dei	Amendment Flag AmendmentFlag	false
CY2017	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--10-01
CY2017	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2017	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2017
CY2017	dei	Document Period End Date DocumentPeriodEndDate	2017-10-01
CY2017	dei	Document Type DocumentType	10-K
CY2017	dei	Entity Central Index Key EntityCentralIndexKey	0000831641
CY2017Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	55722592	shares
CY2017	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2017	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2017Q2	dei	Entity Public Float EntityPublicFloat	2300000000	USD
CY2017	dei	Entity Registrant Name EntityRegistrantName	TETRA TECH INC
CY2017	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2017	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2017	ttek	Billings In Excess Of Cost Period For Revenue Recognition BillingsInExcessOfCostPeriodForRevenueRecognition	P12M
CY2015	ttek	Business Acquisition Contingent Consideration Actual Cash Payment Reported As Cash Flows From Financing Activities BusinessAcquisitionContingentConsiderationActualCashPaymentReportedAsCashFlowsFromFinancingActivities	3199000	USD
CY2016	ttek	Business Acquisition Contingent Consideration Actual Cash Payment Reported As Cash Flows From Financing Activities BusinessAcquisitionContingentConsiderationActualCashPaymentReportedAsCashFlowsFromFinancingActivities	3251000	USD
CY2017	ttek	Business Acquisition Contingent Consideration Actual Cash Payment Reported As Cash Flows From Financing Activities BusinessAcquisitionContingentConsiderationActualCashPaymentReportedAsCashFlowsFromFinancingActivities	1319000	USD
CY2015	ttek	Business Acquisition Contingent Consideration Actual Cash Payment Reported As Cash Flows From Operating Activities BusinessAcquisitionContingentConsiderationActualCashPaymentReportedAsCashFlowsFromOperatingActivities	0	USD
CY2016	ttek	Business Acquisition Contingent Consideration Actual Cash Payment Reported As Cash Flows From Operating Activities BusinessAcquisitionContingentConsiderationActualCashPaymentReportedAsCashFlowsFromOperatingActivities	0	USD
CY2017	ttek	Business Acquisition Contingent Consideration Actual Cash Payment Reported As Cash Flows From Operating Activities BusinessAcquisitionContingentConsiderationActualCashPaymentReportedAsCashFlowsFromOperatingActivities	0	USD
CY2016	ttek	Business Acquisition Contingent Consideration Gain Loss On Change In Value Of Consideration BusinessAcquisitionContingentConsiderationGainLossOnChangeInValueOfConsideration	-2800000	USD
CY2017	ttek	Business Acquisition Contingent Consideration Gain Loss On Change In Value Of Consideration BusinessAcquisitionContingentConsiderationGainLossOnChangeInValueOfConsideration	6900000	USD
CY2016Q4	ttek	Business Acquisition Contingent Consideration Potential Cash Payment Current BusinessAcquisitionContingentConsiderationPotentialCashPaymentCurrent	4296000	USD
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.53
CY2017Q4	ttek	Business Acquisition Contingent Consideration Potential Cash Payment Current BusinessAcquisitionContingentConsiderationPotentialCashPaymentCurrent	2024000	USD
CY2014Q3	ttek	Business Acquisition Contingent Consideration Potential Cash Payment Current And Noncurrent BusinessAcquisitionContingentConsiderationPotentialCashPaymentCurrentAndNoncurrent	7030000	USD
CY2015Q3	ttek	Business Acquisition Contingent Consideration Potential Cash Payment Current And Noncurrent BusinessAcquisitionContingentConsiderationPotentialCashPaymentCurrentAndNoncurrent	4169000	USD
CY2016Q4	ttek	Business Acquisition Contingent Consideration Potential Cash Payment Current And Noncurrent BusinessAcquisitionContingentConsiderationPotentialCashPaymentCurrentAndNoncurrent	8757000	USD
CY2017Q4	ttek	Business Acquisition Contingent Consideration Potential Cash Payment Current And Noncurrent BusinessAcquisitionContingentConsiderationPotentialCashPaymentCurrentAndNoncurrent	2438000	USD
CY2016Q4	ttek	Business Acquisition Contingent Consideration Potential Cash Payment Noncurrent BusinessAcquisitionContingentConsiderationPotentialCashPaymentNoncurrent	4461000	USD
CY2017Q4	ttek	Business Acquisition Contingent Consideration Potential Cash Payment Noncurrent BusinessAcquisitionContingentConsiderationPotentialCashPaymentNoncurrent	414000	USD
CY2016	ttek	Business Combination Acquisition And Integration And Debt Pre Payment Fees BusinessCombinationAcquisitionAndIntegrationAndDebtPrePaymentFees	13300000	USD
CY2015	ttek	Business Combination Acquisition And Integration Related Costs BusinessCombinationAcquisitionAndIntegrationRelatedCosts	0	USD
CY2016	ttek	Business Combination Acquisition And Integration Related Costs BusinessCombinationAcquisitionAndIntegrationRelatedCosts	19548000	USD
CY2017	ttek	Business Combination Acquisition And Integration Related Costs BusinessCombinationAcquisitionAndIntegrationRelatedCosts	0	USD
CY2016	ttek	Business Combination Integration Related Costs And Debt Pre Payment Fees BusinessCombinationIntegrationRelatedCostsAndDebtPrePaymentFees	6900000	USD
CY2016	ttek	Business Combination Professional Service Cost BusinessCombinationProfessionalServiceCost	5685000	USD
CY2016	ttek	Business Combination Real Estate Related Costs BusinessCombinationRealEstateRelatedCosts	2946000	USD
CY2016	ttek	Business Combination Severance Including Change In Control Payments BusinessCombinationSeveranceIncludingChangeInControlPayments	10917000	USD
CY2017	ttek	Concentration Of Credit Risk Number Of Financial Institutions For Investment Exposure ConcentrationOfCreditRiskNumberOfFinancialInstitutionsForInvestmentExposure	1	Institution
CY2016	ttek	Concentration Of Risk Accounts Receivable Percentage Minimum ConcentrationOfRiskAccountsReceivablePercentageMinimum	0.10
CY2017	ttek	Concentration Of Risk Accounts Receivable Percentage Minimum ConcentrationOfRiskAccountsReceivablePercentageMinimum	0.10
CY2015	ttek	Concentration Of Risk Revenue Percentage Minimum ConcentrationOfRiskRevenuePercentageMinimum	0.1
CY2016	ttek	Concentration Of Risk Revenue Percentage Minimum ConcentrationOfRiskRevenuePercentageMinimum	0.1
CY2017	ttek	Concentration Of Risk Revenue Percentage Minimum ConcentrationOfRiskRevenuePercentageMinimum	0.1
CY2016	ttek	Contract Termination Accrual Adjustment ContractTerminationAccrualAdjustment	-2232000	USD
CY2017	ttek	Contract Termination Accrual Adjustment ContractTerminationAccrualAdjustment	-1410000	USD
CY2016	ttek	Contract Termination Cost Transfers ContractTerminationCostTransfers	0	USD
CY2016	ttek	Contract Termination Costs ContractTerminationCosts	2167000	USD
CY2015Q3	ttek	Contract Termination Liability ContractTerminationLiability	3169000	USD
CY2016Q4	ttek	Contract Termination Liability ContractTerminationLiability	3104000	USD
CY2017Q4	ttek	Contract Termination Liability ContractTerminationLiability	1694000	USD
CY2017	ttek	Debt Instrument Number Of Banks With Whom Agreement Entered DebtInstrumentNumberOfBanksWithWhomAgreementEntered	4	Institution
CY2017	ttek	Defined Benefit Plan Minimum Service Period For Eligibility DefinedBenefitPlanMinimumServicePeriodForEligibility	P1Y
CY2015	ttek	Effective Income Tax Rate Reconciliation Change In Uncertain Tax Positions Percent EffectiveIncomeTaxRateReconciliationChangeInUncertainTaxPositionsPercent	0.000
CY2016	ttek	Effective Income Tax Rate Reconciliation Change In Uncertain Tax Positions Percent EffectiveIncomeTaxRateReconciliationChangeInUncertainTaxPositionsPercent	-0.020
CY2017	ttek	Effective Income Tax Rate Reconciliation Change In Uncertain Tax Positions Percent EffectiveIncomeTaxRateReconciliationChangeInUncertainTaxPositionsPercent	0.018
CY2016	ttek	Effective Income Tax Rate Reconciliation Deduction Business Combination Acquisition And Integration Expenses And Debt Pre Payment Fees EffectiveIncomeTaxRateReconciliationDeductionBusinessCombinationAcquisitionAndIntegrationExpensesAndDebtPrePaymentFees	0	USD
CY2015	ttek	Effective Income Tax Rate Reconciliation Goodwill And Contingent Consideration EffectiveIncomeTaxRateReconciliationGoodwillAndContingentConsideration	0.192
CY2016	ttek	Effective Income Tax Rate Reconciliation Goodwill And Contingent Consideration EffectiveIncomeTaxRateReconciliationGoodwillAndContingentConsideration	0.000
CY2017	ttek	Effective Income Tax Rate Reconciliation Goodwill And Contingent Consideration EffectiveIncomeTaxRateReconciliationGoodwillAndContingentConsideration	0.000
CY2015	ttek	Effective Income Tax Rate Reconciliation Non Deductible Executive Compensation Percent EffectiveIncomeTaxRateReconciliationNonDeductibleExecutiveCompensationPercent	0.000
CY2016	ttek	Effective Income Tax Rate Reconciliation Non Deductible Executive Compensation Percent EffectiveIncomeTaxRateReconciliationNonDeductibleExecutiveCompensationPercent	0.020
CY2017	ttek	Effective Income Tax Rate Reconciliation Non Deductible Executive Compensation Percent EffectiveIncomeTaxRateReconciliationNonDeductibleExecutiveCompensationPercent	0.000
CY2016	ttek	Effective Income Tax Rate Reconciliation Nondeductible Expense Business Combination Acquisition Related Expenses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseBusinessCombinationAcquisitionRelatedExpenses	6400000	USD
CY2015	ttek	Estimated Earn Out Liabilities For Acquisitions During The Period EstimatedEarnOutLiabilitiesForAcquisitionsDuringThePeriod	4100000	USD
CY2016	ttek	Estimated Earn Out Liabilities For Acquisitions During The Period EstimatedEarnOutLiabilitiesForAcquisitionsDuringThePeriod	4745000	USD
CY2017	ttek	Estimated Earn Out Liabilities For Acquisitions During The Period EstimatedEarnOutLiabilitiesForAcquisitionsDuringThePeriod	1604000	USD
CY2015	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	3113000	USD
CY2016	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	-2823000	USD
CY2017	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	6923000	USD
CY2015	ttek	Foreign Currency Transaction And Translation Adjustment ForeignCurrencyTransactionAndTranslationAdjustment	-785000	USD
CY2016	ttek	Foreign Currency Transaction And Translation Adjustment ForeignCurrencyTransactionAndTranslationAdjustment	0	USD
CY2017	ttek	Foreign Currency Transaction And Translation Adjustment ForeignCurrencyTransactionAndTranslationAdjustment	59000	USD
CY2017	ttek	Foreign Earnings Repatriated Tax Expense Benefit ForeignEarningsRepatriatedTaxExpenseBenefit	6200000	USD
CY2016Q4	ttek	Government Contract Receivable Billed Amounts GovernmentContractReceivableBilledAmounts	47400000	USD
CY2017Q4	ttek	Government Contract Receivable Billed Amounts GovernmentContractReceivableBilledAmounts	45400000	USD
CY2016Q4	ttek	Government Contract Receivable Unbilled Amounts Related To Claims And Requests For Equitable Adjustment On Contract GovernmentContractReceivableUnbilledAmountsRelatedToClaimsAndRequestsForEquitableAdjustmentOnContract	45000000	USD
CY2017Q4	ttek	Government Contract Receivable Unbilled Amounts Related To Claims And Requests For Equitable Adjustment On Contract GovernmentContractReceivableUnbilledAmountsRelatedToClaimsAndRequestsForEquitableAdjustmentOnContract	59000000	USD
CY2015Q3	ttek	Impairment Of Intangible Assets Indefinite Lived Including Goodwill ImpairmentOfIntangibleAssetsIndefiniteLivedIncludingGoodwill	60800000	USD
CY2015	ttek	Impairment Of Intangible Assets Indefinite Lived Including Goodwill ImpairmentOfIntangibleAssetsIndefiniteLivedIncludingGoodwill	60763000	USD
CY2016	ttek	Impairment Of Intangible Assets Indefinite Lived Including Goodwill ImpairmentOfIntangibleAssetsIndefiniteLivedIncludingGoodwill	0	USD
CY2017	ttek	Impairment Of Intangible Assets Indefinite Lived Including Goodwill ImpairmentOfIntangibleAssetsIndefiniteLivedIncludingGoodwill	0	USD
CY2015Q3	ttek	Impairment Of Intangible Assets Indefinite Lived Including Goodwill Net Of Tax ImpairmentOfIntangibleAssetsIndefiniteLivedIncludingGoodwillNetOfTax	57300000	USD
CY2017	ttek	Income Tax Examination And Settlement Tax Benefit Recognized From Prior Year IncomeTaxExaminationAndSettlementTaxBenefitRecognizedFromPriorYear	1200000	USD
CY2017	ttek	Income Tax Examination Settlements IncomeTaxExaminationSettlements	23000000	USD
CY2016	ttek	Income Tax Rate Reconciliation Effective Income Tax Rate Continuing Operations IncomeTaxRateReconciliationEffectiveIncomeTaxRateContinuingOperations	0.309
CY2017	ttek	Income Tax Rate Reconciliation Effective Income Tax Rate Continuing Operations IncomeTaxRateReconciliationEffectiveIncomeTaxRateContinuingOperations	0.342
CY2015	ttek	Increase Decrease In Accrued Compensation IncreaseDecreaseInAccruedCompensation	-7676000	USD
CY2016	ttek	Increase Decrease In Accrued Compensation IncreaseDecreaseInAccruedCompensation	8434000	USD
CY2017	ttek	Increase Decrease In Accrued Compensation IncreaseDecreaseInAccruedCompensation	13413000	USD
CY2015	ttek	Increase Decrease In Fair Value Of Contingent Consideration Reported In Interest Expense IncreaseDecreaseInFairValueOfContingentConsiderationReportedInInterestExpense	136000	USD
CY2016	ttek	Increase Decrease In Fair Value Of Contingent Consideration Reported In Interest Expense IncreaseDecreaseInFairValueOfContingentConsiderationReportedInInterestExpense	271000	USD
CY2017	ttek	Increase Decrease In Fair Value Of Contingent Consideration Reported In Interest Expense IncreaseDecreaseInFairValueOfContingentConsiderationReportedInInterestExpense	260000	USD
CY2015	ttek	Increase Decrease In Fair Value Of Contingent Consideration Reported In Operating Income IncreaseDecreaseInFairValueOfContingentConsiderationReportedInOperatingIncome	-3113000	USD
CY2016	ttek	Increase Decrease In Fair Value Of Contingent Consideration Reported In Operating Income IncreaseDecreaseInFairValueOfContingentConsiderationReportedInOperatingIncome	2823000	USD
CY2017	ttek	Increase Decrease In Fair Value Of Contingent Consideration Reported In Operating Income IncreaseDecreaseInFairValueOfContingentConsiderationReportedInOperatingIncome	-6923000	USD
CY2015	ttek	Lease Termination Costs And Related Asset Impairment Charges LeaseTerminationCostsAndRelatedAssetImpairmentCharges	342000	USD
CY2016	ttek	Lease Termination Costs And Related Asset Impairment Charges LeaseTerminationCostsAndRelatedAssetImpairmentCharges	2946000	USD
CY2017	ttek	Lease Termination Costs And Related Asset Impairment Charges LeaseTerminationCostsAndRelatedAssetImpairmentCharges	0	USD
CY2015	ttek	Length Of Fiscal Year LengthOfFiscalYear	P364D
CY2016	ttek	Length Of Fiscal Year LengthOfFiscalYear	P371D
CY2017	ttek	Length Of Fiscal Year LengthOfFiscalYear	P364D
CY2017	ttek	Length Of Fiscal Year High End Of Range LengthOfFiscalYearHighEndOfRange	P371D
CY2017	ttek	Length Of Fiscal Year Low End Of Range LengthOfFiscalYearLowEndOfRange	P364D
CY2017	ttek	Maximum Term Of Original Maturity To Classify An Instrument As Cash Equivalent MaximumTermOfOriginalMaturityToClassifyAnInstrumentAsCashEquivalent	P90D
CY2017	ttek	Number Of Levels Below Reportable Segments For Goodwill Impairment Testing NumberOfLevelsBelowReportableSegmentsForGoodwillImpairmentTesting	1	Level
CY2017Q3	ttek	Number Of Reporting Units Having Fair Value In Excess Of Carrying Value Of Less Than Twenty Percent NumberOfReportingUnitsHavingFairValueInExcessOfCarryingValueOfLessThanTwentyPercent	0	reporting_unit
CY2017	ttek	Number Of Steps Involved In Process Of Goodwill Annual Impairment Test NumberOfStepsInvolvedInProcessOfGoodwillAnnualImpairmentTest	2	Step
CY2017	ttek	Number Of Types Of Contracts For Revenue Recognition NumberOfTypesOfContractsForRevenueRecognition	3	Contract
CY2015	ttek	Payments Of Earn Out Liabilities PaymentsOfEarnOutLiabilities	3199000	USD
CY2016	ttek	Payments Of Earn Out Liabilities PaymentsOfEarnOutLiabilities	3251000	USD
CY2017	ttek	Payments Of Earn Out Liabilities PaymentsOfEarnOutLiabilities	1319000	USD
CY2017Q4	ttek	Percentage Of Account Receivables Due From Agencies PercentageOfAccountReceivablesDueFromAgencies	0.23
CY2017Q4	ttek	Revenue Recognition Estimated Cost To Complete Related Contracts RevenueRecognitionEstimatedCostToCompleteRelatedContracts	5000000	USD
CY2015	ttek	Revenue Recognition Net Unfavorable Operating Income Adjustments RevenueRecognitionNetUnfavorableOperatingIncomeAdjustments	8900000	USD
CY2017	ttek	Revenue Recognition Net Unfavorable Operating Income Adjustments RevenueRecognitionNetUnfavorableOperatingIncomeAdjustments	8000000	USD
CY2015	ttek	Selling General And Administrative Expenses Including Depreciation And Amortization Of Intangible Assets SellingGeneralAndAdministrativeExpensesIncludingDepreciationAndAmortizationOfIntangibleAssets	170456000	USD
CY2016	ttek	Selling General And Administrative Expenses Including Depreciation And Amortization Of Intangible Assets SellingGeneralAndAdministrativeExpensesIncludingDepreciationAndAmortizationOfIntangibleAssets	171985000	USD
CY2017	ttek	Selling General And Administrative Expenses Including Depreciation And Amortization Of Intangible Assets SellingGeneralAndAdministrativeExpensesIncludingDepreciationAndAmortizationOfIntangibleAssets	177219000	USD
CY2015	ttek	Subcontractor Costs SubcontractorCosts	580606000	USD
CY2016	ttek	Subcontractor Costs SubcontractorCosts	654264000	USD
CY2017	ttek	Subcontractor Costs SubcontractorCosts	719350000	USD
CY2017	ttek	Unbilled Contracts Receivable Period For Billing And Collection UnbilledContractsReceivablePeriodForBillingAndCollection	P12M
CY2016	ttek	Unrecognized Tax Benefits Accrued Interest Expense From Settlements With Taxing Authorities UnrecognizedTaxBenefitsAccruedInterestExpenseFromSettlementsWithTaxingAuthorities	200000	USD
CY2017	ttek	Unrecognized Tax Benefits Accrued Interest Expense From Settlements With Taxing Authorities UnrecognizedTaxBenefitsAccruedInterestExpenseFromSettlementsWithTaxingAuthorities	400000	USD
CY2017	ttek	Unrecognized Tax Benefits Period To Affect Tax Rate UnrecognizedTaxBenefitsPeriodToAffectTaxRate	P12M
CY2016Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	158773000	USD
CY2017Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	177638000	USD
CY2016Q4	us-gaap	Accounts Receivable Gross Current AccountsReceivableGrossCurrent	749569000	USD
CY2017Q4	us-gaap	Accounts Receivable Gross Current AccountsReceivableGrossCurrent	821026000	USD
CY2016Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	714336000	USD
CY2017Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	788767000	USD
CY2016Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	146867000	USD
CY2017Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	124560000	USD
CY2016Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-128008000	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-98500000	USD
CY2016Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	260340000	USD
CY2017Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	193835000	USD
CY2015	us-gaap	Adjustments To Additional Paid In Capital Income Tax Deficiency From Share Based Compensation AdjustmentsToAdditionalPaidInCapitalIncomeTaxDeficiencyFromShareBasedCompensation	574000	USD
CY2016	us-gaap	Adjustments To Additional Paid In Capital Income Tax Deficiency From Share Based Compensation AdjustmentsToAdditionalPaidInCapitalIncomeTaxDeficiencyFromShareBasedCompensation	271000	USD
CY2015	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	10926000	USD
CY2016	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	12964000	USD
CY2017	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	13450000	USD
CY2015	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	10926000	USD
CY2016	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	12964000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	13450000	USD
CY2015	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	7115000	USD
CY2016	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	8308000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	8735000	USD
CY2016Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	35233000	USD
CY2017Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	32259000	USD
CY2015	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	20200000	USD
CY2016	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	22100000	USD
CY2017	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	22800000	USD
CY2016Q4	us-gaap	Assets Assets	1800779000	USD
CY2017Q4	us-gaap	Assets Assets	1902745000	USD
CY2016Q4	us-gaap	Assets Current AssetsCurrent	935428000	USD
CY2017Q4	us-gaap	Assets Current AssetsCurrent	1042023000	USD
CY2016Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	364287000	USD
CY2017Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	376287000	USD
CY2016Q4	us-gaap	Billings In Excess Of Cost Current BillingsInExcessOfCostCurrent	88223000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	147382000	USD
CY2015	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	11000	USD
CY2017Q4	us-gaap	Billings In Excess Of Cost Current BillingsInExcessOfCostCurrent	117499000	USD
CY2016	us-gaap	Business Combination Contingent Consideration Arrangements Change In Amount Of Contingent Consideration Liability1 BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1	2800000	USD
CY2017	us-gaap	Business Combination Contingent Consideration Arrangements Change In Amount Of Contingent Consideration Liability1 BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1	-6900000	USD
CY2017Q4	us-gaap	Business Combination Contingent Consideration Arrangements Range Of Outcomes Value High BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh	8900000	USD
CY2015Q3	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	0	USD
CY2017Q4	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	2400000	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Due CapitalLeasesFutureMinimumPaymentsDue	369000	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Due Current CapitalLeasesFutureMinimumPaymentsDueCurrent	158000	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Due In Five Years CapitalLeasesFutureMinimumPaymentsDueInFiveYears	0	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Due In Four Years CapitalLeasesFutureMinimumPaymentsDueInFourYears	0	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Due In Three Years CapitalLeasesFutureMinimumPaymentsDueInThreeYears	0	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Due In Two Years CapitalLeasesFutureMinimumPaymentsDueInTwoYears	211000	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Due Thereafter CapitalLeasesFutureMinimumPaymentsDueThereafter	0	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Interest Included In Payments CapitalLeasesFutureMinimumPaymentsInterestIncludedInPayments	2000	USD
CY2017Q4	us-gaap	Capital Leases Future Minimum Payments Present Value Of Net Minimum Payments CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments	367000	USD
CY2014Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	122379000	USD
CY2015Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	135326000	USD
CY2016Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	160459000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	189975000	USD
CY2015	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	12947000	USD
CY2016	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	25133000	USD
CY2017	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	29516000	USD
CY2016Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2017Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2015	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.30
CY2015	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.3
CY2016	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.34
CY2017	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.38
CY2016Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.09
CY2017Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.09
CY2017Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.10
CY2017Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.10
CY2016Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2017Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2016Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	150000000	shares
CY2017Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	150000000	shares
CY2016Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	57042000	shares
CY2017Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	55873000	shares
CY2016Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	57042000	shares
CY2017Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	55873000	shares
CY2017Q4	us-gaap	Common Stock Value CommonStockValue	559000	USD
CY2016	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	99019000	USD
CY2015	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-61559000	USD
CY2016	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	98946000	USD
CY2016Q4	us-gaap	Common Stock Value CommonStockValue	570000	USD
CY2016	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	73000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	51000	USD
CY2015	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-61548000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	147433000	USD
CY2016Q4	us-gaap	Contract Receivable Retainage ContractReceivableRetainage	29135000	USD
CY2017Q4	us-gaap	Contract Receivable Retainage ContractReceivableRetainage	39840000	USD
CY2015	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	23836000	USD
CY2016	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	22277000	USD
CY2017	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	45604000	USD
CY2015	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	3773000	USD
CY2016	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	6651000	USD
CY2017	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	9337000	USD
CY2015	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	32681000	USD
CY2016	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	34562000	USD
CY2017	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	63801000	USD
CY2015	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	5072000	USD
CY2016	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	5634000	USD
CY2017	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	8860000	USD
CY2016Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	347011000	USD
CY2017Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	356871000	USD
CY2016Q4	us-gaap	Deferred Compensation Liability Classified Noncurrent DeferredCompensationLiabilityClassifiedNoncurrent	20800000	USD
CY2017Q4	us-gaap	Deferred Compensation Liability Classified Noncurrent DeferredCompensationLiabilityClassifiedNoncurrent	25200000	USD
CY2016Q4	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	20900000	USD
CY2017Q4	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	25000000	USD
CY2015	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	7218000	USD
CY2016	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	6231000	USD
CY2017	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-4251000	USD
CY2015	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-1141000	USD
CY2016	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-164000	USD
CY2017	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-4761000	USD
CY2016Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	630000	USD
CY2017Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	1763000	USD
CY2015	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	8412000	USD
CY2016	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	6051000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-9957000	USD
CY2016Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	100185000	USD
CY2017Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	85300000	USD
CY2016Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	60348000	USD
CY2017Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	43781000	USD
CY2015	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	2335000	USD
CY2016	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-16000	USD
CY2017	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-945000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Goodwill And Intangible Assets DeferredTaxAssetsGoodwillAndIntangibleAssets	0	USD
CY2017Q4	us-gaap	Deferred Tax Assets Goodwill And Intangible Assets DeferredTaxAssetsGoodwillAndIntangibleAssets	0	USD
CY2015	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.64
CY2015Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.39
CY2016Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.06
CY2016Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.44
CY2017Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	598000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	40467000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	43282000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	23514000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	28261000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	697000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	10684000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	10069000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	24663000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	22466000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	3817000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	4273000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves	2539000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves	2941000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	25447000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	25326000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	25300000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	59718000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	42018000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	33268000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	24328000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	2921000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	6253000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	9358000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	8311000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Tax Deferred Income DeferredTaxLiabilitiesTaxDeferredIncome	54638000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Tax Deferred Income DeferredTaxLiabilitiesTaxDeferredIncome	46408000	USD
CY2015	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	9800000	USD
CY2016	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	10700000	USD
CY2017	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	11400000	USD
CY2015	us-gaap	Depreciation Depreciation	23110000	USD
CY2015	us-gaap	Depreciation Depreciation	23100000	USD
CY2016	us-gaap	Depreciation Depreciation	22800000	USD
CY2016	us-gaap	Depreciation Depreciation	22756000	USD
CY2017	us-gaap	Depreciation Depreciation	22200000	USD
CY2017	us-gaap	Depreciation Depreciation	22207000	USD
CY2015	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	44201000	USD
CY2016	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	45588000	USD
CY2017	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	45756000	USD
CY2015	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	18240000	USD
CY2016	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	19735000	USD
CY2017	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	21672000	USD
CY2015	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.64
CY2015Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.39
CY2016Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.06
CY2016Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.44
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.54
CY2016	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.44
CY2017Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.47
CY2017Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.47
CY2017Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.52
CY2017Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.61
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.07
CY2016Q4	us-gaap	Equity Method Investments EquityMethodInvestments	2064000	USD
CY2016	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.42
CY2017Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.46
CY2017Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.46
CY2017Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.52
CY2017Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.60
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.04
CY2015	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents Continuing Operations EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations	-5301000	USD
CY2016	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents Continuing Operations EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations	2516000	USD
CY2017	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents Continuing Operations EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations	3256000	USD
CY2015	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.512
CY2016	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.326
CY2017	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.313
CY2015	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35
CY2016	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.057
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.024
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.005
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.008
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.007
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.007
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.038
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.016
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.000
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.005
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.003
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.028
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.001
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.014
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.002
CY2015	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.050
CY2016	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.031
CY2017	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.034
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.038
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.034
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.018
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.059
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.039
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.029
CY2016Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	129184000	USD
CY2017Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	143408000	USD
CY2015	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	3811000	USD
CY2016	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	4656000	USD
CY2017	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	4715000	USD
CY2015	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	5252000	USD
CY2016	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	2796000	USD
CY2017	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	4052000	USD
CY2017Q4	us-gaap	Equity Method Investments EquityMethodInvestments	2700000	USD
CY2015	us-gaap	Excess Tax Benefit From Share Based Compensation Financing Activities ExcessTaxBenefitFromShareBasedCompensationFinancingActivities	172000	USD
CY2016	us-gaap	Excess Tax Benefit From Share Based Compensation Financing Activities ExcessTaxBenefitFromShareBasedCompensationFinancingActivities	918000	USD
CY2017	us-gaap	Excess Tax Benefit From Share Based Compensation Financing Activities ExcessTaxBenefitFromShareBasedCompensationFinancingActivities	0	USD
CY2015	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	172000	USD
CY2016	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	918000	USD
CY2017	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	0	USD
CY2016Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	95082000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	92307000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	229000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	14548000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	411000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	1664000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	2802000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	7034000	USD
CY2016	us-gaap	Finite Lived Intangible Assets Foreign Currency Translation Gain Loss FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss	-1100000	USD
CY2017	us-gaap	Finite Lived Intangible Assets Foreign Currency Translation Gain Loss FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss	-100000	USD
CY2016Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	144044000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	118995000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	26688000	USD
CY2015	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	6014000	USD
CY2016	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	537000	USD
CY2017	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	103000	USD
CY2015Q3	us-gaap	Goodwill Goodwill	601379000	USD
CY2016Q4	us-gaap	Goodwill Goodwill	717988000	USD
CY2017Q4	us-gaap	Goodwill Goodwill	740886000	USD
CY2016	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	107618000	USD
CY2017	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	7055000	USD
CY2016	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	7304000	USD
CY2017	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	15138000	USD
CY2017Q3	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2015Q3	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	58100000	USD
CY2016	us-gaap	Goodwill Other Increase Decrease GoodwillOtherIncreaseDecrease	1687000	USD
CY2017	us-gaap	Goodwill Other Increase Decrease GoodwillOtherIncreaseDecrease	705000	USD
CY2016Q4	us-gaap	Government Contract Receivable Unbilled Amounts GovernmentContractReceivableUnbilledAmounts	92200000	USD
CY2017Q4	us-gaap	Government Contract Receivable Unbilled Amounts GovernmentContractReceivableUnbilledAmounts	109700000	USD
CY2015	us-gaap	Gross Profit GrossProfit	315790000	USD
CY2016	us-gaap	Gross Profit GrossProfit	330211000	USD
CY2017	us-gaap	Gross Profit GrossProfit	353638000	USD
CY2015Q3	us-gaap	Impairment Of Intangible Assets Excluding Goodwill ImpairmentOfIntangibleAssetsExcludingGoodwill	2700000	USD
CY2016	us-gaap	Impairment Of Leasehold ImpairmentOfLeasehold	2900000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	118822000	USD
CY2016	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	113576000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	166074000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	80321000	USD
CY2016	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	124466000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	171761000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	-38501000	USD
CY2016	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	10890000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	5687000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	80321000	USD
CY2016	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	124466000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	171761000	USD
CY2015	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	5131000	USD
CY2016	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	1652000	USD
CY2017	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	4699000	USD
CY2015	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	41093000	USD
CY2016	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	40613000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	53844000	USD
CY2016	us-gaap	Income Tax Reconciliation Tax Credits Research IncomeTaxReconciliationTaxCreditsResearch	2000000	USD
CY2015	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	23268000	USD
CY2016	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	35273000	USD
CY2017	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	72578000	USD
CY2016Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	14371000	USD
CY2017Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	13312000	USD
CY2015	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-26901000	USD
CY2016	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-3002000	USD
CY2017	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	18597000	USD
CY2015	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-40345000	USD
CY2016	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-9062000	USD
CY2017	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	64781000	USD
CY2015	us-gaap	Increase Decrease In Billing In Excess Of Cost Of Earnings IncreaseDecreaseInBillingInExcessOfCostOfEarnings	-10319000	USD
CY2016	us-gaap	Increase Decrease In Billing In Excess Of Cost Of Earnings IncreaseDecreaseInBillingInExcessOfCostOfEarnings	-13874000	USD
CY2017	us-gaap	Increase Decrease In Billing In Excess Of Cost Of Earnings IncreaseDecreaseInBillingInExcessOfCostOfEarnings	28298000	USD
CY2015	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	7911000	USD
CY2016	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	-4995000	USD
CY2017	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	-13725000	USD
CY2015	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-7143000	USD
CY2016	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-19321000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	2167000	USD
CY2015	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-12970000	USD
CY2016	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-3720000	USD
CY2017	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	8317000	USD
CY2015	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	-4530000	USD
CY2016	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	2519000	USD
CY2017	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	0	USD
CY2015	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	619000	shares
CY2016	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	780000	shares
CY2017	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1002000	shares
CY2016Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	48962000	USD
CY2017Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	26688000	USD
CY2015	us-gaap	Interest Expense InterestExpense	8043000	USD
CY2016	us-gaap	Interest Expense InterestExpense	12385000	USD
CY2017	us-gaap	Interest Expense InterestExpense	12310000	USD
CY2015	us-gaap	Interest Paid Net InterestPaidNet	7323000	USD
CY2016	us-gaap	Interest Paid Net InterestPaidNet	12575000	USD
CY2017	us-gaap	Interest Paid Net InterestPaidNet	11504000	USD
CY2015	us-gaap	Investment Income Interest InvestmentIncomeInterest	680000	USD
CY2016	us-gaap	Investment Income Interest InvestmentIncomeInterest	996000	USD
CY2017	us-gaap	Investment Income Interest InvestmentIncomeInterest	729000	USD
CY2015	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	66400000	USD
CY2016	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	75000000	USD
CY2017	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	71300000	USD
CY2016Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1800779000	USD
CY2017Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1902745000	USD
CY2016Q4	us-gaap	Liabilities Current LiabilitiesCurrent	481086000	USD
CY2017Q4	us-gaap	Liabilities Current LiabilitiesCurrent	537668000	USD
CY2017Q4	us-gaap	Line Of Credit LineOfCredit	356400000	USD
CY2016Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	331501000	USD
CY2017Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	341283000	USD
CY2016Q4	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	15510000	USD
CY2017Q4	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	15588000	USD
CY2017Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	0	USD
CY2017Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	15588000	USD
CY2017Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	0	USD
CY2017Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	0	USD
CY2017Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	325688000	USD
CY2017Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	15595000	USD
CY2016Q4	us-gaap	Minority Interest MinorityInterest	144000	USD
CY2017Q4	us-gaap	Minority Interest MinorityInterest	171000	USD
CY2015	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	515000	USD
CY2016	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	402000	USD
CY2017	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	24000	USD
CY2015	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	-123579000	USD
CY2016	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	-25388000	USD
CY2017	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	-94772000	USD
CY2015	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	-21020000	USD
CY2016	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	-94015000	USD
CY2017	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	-16960000	USD
CY2015	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	162847000	USD
CY2016	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	142020000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	137992000	USD
CY2015	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	154000	USD
CY2016	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	70000	USD
CY2017	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	43000	USD
CY2015	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	39074000	USD
CY2015Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	23239000	USD
CY2016Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	3744000	USD
CY2016Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	25694000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	31106000	USD
CY2016	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	83783000	USD
CY2017Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	26562000	USD
CY2017Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	26862000	USD
CY2017Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	29983000	USD
CY2017Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	34467000	USD
CY2017	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	117874000	USD
CY2017	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2016	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	17107000	USD
CY2017	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	30257000	USD
CY2015	us-gaap	Operating Income Loss OperatingIncomeLoss	87684000	USD
CY2015Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	32930000	USD
CY2016Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	16650000	USD
CY2016Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	39085000	USD
	us-gaap	Operating Income Loss OperatingIncomeLoss	47190000	USD
CY2016	us-gaap	Operating Income Loss OperatingIncomeLoss	135855000	USD
CY2017Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	39855000	USD
CY2017Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	42956000	USD
CY2017Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	45884000	USD
CY2017Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	54647000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	183342000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	254165000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	77854000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	17261000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	28740000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	45906000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	62634000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	21770000	USD
CY2016Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	27880000	USD
CY2017Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	31850000	USD
CY2015	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToNoncontrollingInterest	-143000	USD
CY2016	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToNoncontrollingInterest	3000	USD
CY2017	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToNoncontrollingInterest	8000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-98287000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	14392000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	27902000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-100776000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	15166000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	29516000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	15163000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	29508000	USD
CY2015	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-2489000	USD
CY2016	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	774000	USD
CY2017	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	1614000	USD
CY2015	us-gaap	Other Cost Of Operating Revenue OtherCostOfOperatingRevenue	1402925000	USD
CY2016	us-gaap	Other Cost Of Operating Revenue OtherCostOfOperatingRevenue	1598994000	USD
CY2017	us-gaap	Other Cost Of Operating Revenue OtherCostOfOperatingRevenue	1680372000	USD
CY2016Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	85100000	USD
CY2017Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	81511000	USD
CY2016Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	53980000	USD
CY2017Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	50975000	USD
CY2015	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	100500000	USD
CY2016	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	99500000	USD
CY2017	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	100000000	USD
CY2015	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	1457000	USD
CY2016	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	1935000	USD
CY2017	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	0	USD
CY2015	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	18240000	USD
CY2016	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	19735000	USD
CY2017	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	21672000	USD
CY2015	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	515000	USD
CY2016	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	402000	USD
CY2017	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	24000	USD
CY2016	us-gaap	Payments Of Ordinary Dividends PaymentsOfOrdinaryDividends	19700000	USD
CY2017	us-gaap	Payments Of Ordinary Dividends PaymentsOfOrdinaryDividends	21700000	USD
CY2015	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	11680000	USD
CY2016	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	81259000	USD
CY2017	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	8039000	USD
CY2015	us-gaap	Payments To Acquire Interest In Joint Venture PaymentsToAcquireInterestInJointVenture	0	USD
CY2016	us-gaap	Payments To Acquire Interest In Joint Venture PaymentsToAcquireInterestInJointVenture	1368000	USD
CY2017	us-gaap	Payments To Acquire Interest In Joint Venture PaymentsToAcquireInterestInJointVenture	85000	USD
CY2015	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	24296000	USD
CY2016	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	11945000	USD
CY2017	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	9741000	USD
CY2016Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2017Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2016Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2017Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2016Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2017Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2016Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2017Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2016Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2017Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2016Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	46262000	USD
CY2017Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	49969000	USD
CY2015	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	5400000	USD
CY2016	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	3200000	USD
CY2017	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	2100000	USD
CY2015	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	10825000	USD
CY2016	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	17953000	USD
CY2017	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	18555000	USD
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CY2016	us-gaap	Proceeds From Issuance Of Long Term Debt And Capital Securities Net ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet	229049000	USD
CY2017	us-gaap	Proceeds From Issuance Of Long Term Debt And Capital Securities Net ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet	243553000	USD
CY2015	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	10426000	USD
CY2016	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	3076000	USD
CY2017	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	905000	USD
CY2015	us-gaap	Profit Loss ProfitLoss	39228000	USD
CY2016	us-gaap	Profit Loss ProfitLoss	83853000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	117917000	USD
CY2016Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	214694000	USD
CY2017Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	181395000	USD
CY2016Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	67827000	USD
CY2017Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	56835000	USD
CY2015	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-1034000	USD
CY2016	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	8082000	USD
CY2017	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	2847000	USD
CY2016Q4	us-gaap	Provision For Loss On Contracts ProvisionForLossOnContracts	6700000	USD
CY2017Q4	us-gaap	Provision For Loss On Contracts ProvisionForLossOnContracts	8100000	USD
CY2016	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	1944000	USD
CY2017	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	749000	USD
CY2015	us-gaap	Repayments Of Long Term Debt And Capital Securities RepaymentsOfLongTermDebtAndCapitalSecurities	75459000	USD
CY2016	us-gaap	Repayments Of Long Term Debt And Capital Securities RepaymentsOfLongTermDebtAndCapitalSecurities	148485000	USD
CY2017	us-gaap	Repayments Of Long Term Debt And Capital Securities RepaymentsOfLongTermDebtAndCapitalSecurities	233865000	USD
CY2017Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	2700000	USD
CY2016Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	736357000	USD
CY2017Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	832559000	USD
CY2015	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	2299321000	USD
CY2015Q4	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	560708000	USD
CY2016Q1	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	627384000	USD
CY2016Q2	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	666869000	USD
	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	728508000	USD
CY2016	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	2583469000	USD
CY2017Q1	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	668851000	USD
CY2017Q2	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	663781000	USD
CY2017Q3	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	685539000	USD
CY2017Q4	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	735188000	USD
CY2017	us-gaap	Sales Revenue Services Net SalesRevenueServicesNet	2753360000	USD
CY2015	us-gaap	Share Based Compensation ShareBasedCompensation	10926000	USD
CY2016	us-gaap	Share Based Compensation ShareBasedCompensation	12964000	USD
CY2017	us-gaap	Share Based Compensation ShareBasedCompensation	13450000	USD
CY2016	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1	P1Y
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1	P1Y
CY2015	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	5203000	USD
CY2016	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	4707000	USD
CY2017	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	4940000	USD
CY2015	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	8990000	USD
CY2016	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	15823000	USD
CY2017	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	15094000	USD
CY2016Q4	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	200000000	USD
CY2015	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	100500000	USD
CY2016	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	99500000	USD
CY2017	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	100000000	USD
CY2016Q4	us-gaap	Stockholders Equity StockholdersEquity	869259000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	928453000	USD
CY2014Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1013056000	USD
CY2015Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	856798000	USD
CY2016Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	869403000	USD
CY2017Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	928624000	USD
CY2016	us-gaap	Tax Adjustments Settlements And Unusual Provisions TaxAdjustmentsSettlementsAndUnusualProvisions	0	USD
CY2017	us-gaap	Tax Adjustments Settlements And Unusual Provisions TaxAdjustmentsSettlementsAndUnusualProvisions	900000	USD
CY2017	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	44.12
CY2017	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	2266397	shares
CY2017	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	100000000	USD
CY2016Q4	us-gaap	Unbilled Contracts Receivable UnbilledContractsReceivable	356147000	USD
CY2017Q4	us-gaap	Unbilled Contracts Receivable UnbilledContractsReceivable	404899000	USD
CY2017Q4	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	68400000	USD
CY2014Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	21717000	USD
CY2015Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	21618000	USD
CY2016Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	22786000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	9337000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	23000	USD
CY2016	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	3100000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	6875000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	3532000	USD
CY2016	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2017	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	9999000	USD
CY2016Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	1000000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	1100000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1147000	USD
CY2016	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	2802000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1060000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	2309000	USD
CY2016	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	1466000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	2365000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	9300000	USD
CY2015	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	61532000	shares
CY2015Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	59793000	shares
CY2016Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	59131000	shares
CY2016Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58616000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58192000	shares
CY2016	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58966000	shares
CY2017Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58145000	shares
CY2017Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58270000	shares
CY2017Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58161000	shares
CY2017Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57326000	shares
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57913000	shares
CY2015	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	60913000	shares
CY2015Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	59058000	shares
CY2016Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	58451000	shares
CY2016Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57796000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57309000	shares
CY2016	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	58186000	shares
CY2017Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57099000	shares
CY2017Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57270000	shares
CY2017Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57184000	shares
CY2017Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56338000	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56911000	shares
CY2017	us-gaap	Fiscal Period FiscalPeriod	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Fiscal Year.</font><font style="font-family:inherit;font-size:10pt;">    We report results of operations based on 52 or 53-week periods ending on the Sunday nearest September 30. Fiscal years </font><font style="font-family:inherit;font-size:10pt;">2017</font><font style="font-family:inherit;font-size:10pt;">, </font><font style="font-family:inherit;font-size:10pt;">2016</font><font style="font-family:inherit;font-size:10pt;"> and </font><font style="font-family:inherit;font-size:10pt;">2015</font><font style="font-family:inherit;font-size:10pt;"> contained 52, 53 and 52 weeks, respectively.</font></div></div>
CY2017	us-gaap	Nature Of Operations NatureOfOperations	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-weight:bold;">Description of Business</font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">We are a leading provider of consulting and engineering services that focuses on water, environment, infrastructure, resource management, energy, and international development. We are a global company that is renowned for our expertise in providing water-related services for public and private clients. We typically begin at the earliest stage of a project by identifying technical solutions and developing execution plans tailored to our clients' needs and resources. Our solutions may span the entire life cycle of consulting and engineering projects and include applied science, data analysis, research, engineering, design, construction management, and operations and maintenance.</font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">In fiscal </font><font style="font-family:inherit;font-size:10pt;">2017</font><font style="font-family:inherit;font-size:10pt;">, we managed our operations under </font><font style="font-family:inherit;font-size:10pt;">three</font><font style="font-family:inherit;font-size:10pt;"> reportable segments. We report our water resources, water and wastewater treatment, environment, and infrastructure engineering activities in the Water, Environment and Infrastructure ("WEI") reportable segment. Our Resource Management and Energy ("RME") reportable segment includes our oil and gas, energy, international development, waste management, remediation, and utilities services. In addition, we report the results of the wind-down of our non-core construction activities in the Remediation and Construction Management ("RCM") reportable segment.</font></div></div>
CY2017	us-gaap	Revenue Recognition Long Term Contracts RevenueRecognitionLongTermContracts	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Revenue Recognition and Contract Costs.</font><font style="font-family:inherit;font-size:10pt;">    We recognize revenue for most of our contracts using the percentage-of-completion method, primarily based on contract costs incurred to date compared to total estimated contract costs. We generally utilize the cost-to-cost approach to estimate the progress towards completion in order to determine the amount of revenue and profit to recognize. Revenue and cost estimates for each significant contract are reviewed and reassessed quarterly. Changes in those estimates could result in recognition of cumulative catch-up adjustments to the contract's inception-to-date revenue, costs, and profit in the period in which such changes are made. Changes in revenue and cost estimates could also result in a projected loss that would be recorded immediately in earnings. </font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">We recognize revenue for work performed under </font><font style="font-family:inherit;font-size:10pt;">three</font><font style="font-family:inherit;font-size:10pt;"> major types of contracts: fixed-price, time-and-materials and cost-plus.</font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Fixed-Price.</font><font style="font-family:inherit;font-size:10pt;">     Under fixed-price contracts, our clients pay us an agreed fixed-amount negotiated in advance for a specified scope of work. We generally recognize revenue on fixed-price contracts using the percentage-of-completion method. If the nature or circumstances of the contract prevent us from preparing a reliable estimate at completion, we will delay profit recognition until adequate information about the contract's progress becomes available. </font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Time-and-Materials.</font><font style="font-family:inherit;font-size:10pt;">    Under time-and-materials contracts, we negotiate hourly billing rates and charge our clients based on the actual time that we spend on a project. In addition, clients reimburse us for our actual out-of-pocket costs for materials and other direct incidental expenditures that we incur in connection with our performance under the contract. The majority of our time-and-material contracts are subject to maximum contract values and, accordingly, revenue under these contracts is generally recognized under the percentage-of-completion method. However, time and materials contracts that are service-related contracts are accounted for utilizing the proportional performance method. Revenue on contracts that are not subject to maximum contract values is recognized based on the actual number of hours we spend on the projects plus any actual out-of-pocket costs of materials and other direct incidental expenditures that we incur on the projects. Our time-and-materials contracts also generally include annual billing rate adjustment provisions.</font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Cost-Plus.</font><font style="font-family:inherit;font-size:10pt;font-weight:bold;"> </font><font style="font-family:inherit;font-size:10pt;">   Under cost-plus contracts, we are reimbursed for allowable or otherwise defined costs incurred plus a negotiated fee. The contracts may also include incentives for various performance criteria, including quality, timeliness, ingenuity, safety and cost-effectiveness. In addition, our costs are generally subject to review by our clients and regulatory audit agencies, and such reviews could result in costs being disputed as non-reimbursable under the terms of the contract. Revenue for cost-plus contracts is recognized at the time services are performed. Revenue is not recognized for non-recoverable costs. Performance incentives are included in our estimates of revenue when their realization is reasonably assured.</font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">If estimated total costs on any contract indicate a loss, we recognize the entire estimated loss in the period the loss becomes known. The cumulative effect of revisions to revenue, estimated costs to complete contracts, including penalties, incentive awards, change orders, claims, liquidated damages, anticipated losses, and other revisions are recorded in the period in which the revisions are identified and the loss can be reasonably estimated. Such revisions could occur in any reporting period and the effects may be material depending on the size of the project or the adjustment.</font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:56px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">Once contract performance is underway, we may experience changes in conditions, client requirements, specifications, designs, materials, and expectations regarding the period of performance. Such changes are "change orders" and may be initiated by us or by our clients. In many cases, agreement with the client as to the terms of change orders is reached prior to work commencing; however, sometimes circumstances require that work progress without obtaining client agreement. Revenue related to change orders is recognized as costs are incurred. Change orders that are unapproved as to both price and scope are evaluated as claims.</font></div><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:56px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">Claims are amounts in excess of agreed contract prices that we seek to collect from our clients or other third parties for delays, errors in specifications and designs, contract terminations, change orders in dispute or unapproved as to both scope and price, or other causes of unanticipated additional costs. Revenue on claims is recognized only to the extent that contract costs related to the claims have been incurred and when it is probable that the claim will result in a bona fide addition to contract value that can be reliably estimated. No profit is recognized on a claim until final settlement occurs. This can lead to a situation in which costs are recognized in one period and revenue is recognized in a subsequent period when a client agreement is obtained or a claims resolution occurs.</font></div></div>
CY2017	us-gaap	Use Of Estimates UseOfEstimates	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-bottom:8px;padding-top:8px;text-align:justify;text-indent:48px;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:inherit;font-size:10pt;">    The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") requires us to make estimates and assumptions. These estimates and assumptions affect the amounts reported in our consolidated financial statements and accompanying notes. Although such estimates and assumptions are based on management's best knowledge of current events and actions we may take in the future, actual results could differ materially from those estimates.</font></div></div>

Files In Submission

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$TTEK
TETRA TECH INC Stock $ttek

2017 Q3 Form 10-K Financial Statement

#000083164117000022 Filed on November 20, 2017

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$TTEK TETRA TECH INC Stock $ttek

2017 Q3 Form 10-K Financial Statement

#000083164117000022 Filed on November 20, 2017

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$TTEK
TETRA TECH INC Stock $ttek