$SEIC
SEI INVESTMENTS CO Stock $seic

$seic Overview Financials Valuation SEC Filings Company Website

2018 Q1 Form 10-K Financial Statement

#000035089418000011 Filed on February 22, 2018

Income Statement

Concept	2018 Q1	2017 Q4	2016 Q4
Revenue	$405.6M	$408.2M	$368.8M
YoY Change	12.67%	10.69%	9.96%
Cost Of Revenue	$71.50M	$78.50M	$78.80M
YoY Change	-1.52%	-0.38%	7.07%
Gross Profit	$131.3M	$329.7M	$290.0M
YoY Change	21.4%	13.69%	10.77%
Gross Profit Margin	32.36%	80.77%	78.63%
Selling, General & Admin	$198.8M	$205.8M	$173.2M
YoY Change	13.6%	18.82%	6.52%
% of Gross Profit	151.46%	62.42%	59.72%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$7.122M	$17.00M	$18.60M
YoY Change	4.74%	-8.6%	10.06%
% of Gross Profit	5.43%	5.16%	6.41%
Operating Expenses	$217.8M	$222.8M	$191.9M
YoY Change	12.33%	16.1%	6.85%
Operating Profit	$116.3M	$106.9M	$98.10M
YoY Change	24.38%	8.97%	19.34%
Interest Expense	$257.0K	$45.50M	$34.90M
YoY Change	129.46%	30.37%	6.08%
% of Operating Profit	0.22%	42.56%	35.58%
Other Income/Expense, Net
YoY Change
Pretax Income	$158.8M	$152.5M	$133.1M
YoY Change	23.39%	14.58%	15.62%
Income Tax	$18.92M	$42.70M	$44.40M
% Of Pretax Income	11.92%	28.01%	33.37%
Net Earnings	$139.8M	$122.1M	$88.61M
YoY Change	57.59%	37.84%	8.89%
Net Earnings / Revenue	34.48%	29.92%	24.03%
Basic Earnings Per Share	$0.89	$0.78	$0.55
Diluted Earnings Per Share	$0.86	$0.75	$0.55
COMMON SHARES
Basic Shares Outstanding	157.3M shares	157.5M shares	160.0M shares
Diluted Shares Outstanding	163.4M shares

Balance Sheet

Concept	2018 Q1	2017 Q4	2016 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments	$769.9M	$765.8M	$717.0M
YoY Change	12.77%	6.81%	2.3%
Cash & Equivalents	$748.3M	$744.2M	$695.7M
Short-Term Investments	$21.60M	$21.50M	$21.30M
Other Short-Term Assets	$34.72M	$31.16M	$27.58M
YoY Change	16.23%	12.99%	5.22%
Inventory
Prepaid Expenses
Receivables	$347.3M	$327.1M	$278.9M
Other Receivables	$15.90M	$12.30M	$10.80M
Total Short-Term Assets	$1.171B	$1.140B	$1.038B
YoY Change	14.86%	9.83%	3.4%
LONG-TERM ASSETS
Property, Plant & Equipment	$145.3M	$146.4M	$146.2M
YoY Change	1.79%	0.16%	1.54%
Goodwill	$52.99M	$52.99M	$0.00
YoY Change
Intangibles	$27.80M	$28.58M	$0.00
YoY Change
Long-Term Investments	$143.1M	$153.5M	$139.4M
YoY Change	-0.07%	10.11%	3.34%
Other Assets	$18.33M	$18.88M	$15.46M
YoY Change	12.89%	22.18%	-0.23%
Total Long-Term Assets	$722.4M	$713.6M	$599.0M
YoY Change	19.45%	19.13%	2.41%
TOTAL ASSETS
Total Short-Term Assets	$1.171B	$1.140B	$1.038B
Total Long-Term Assets	$722.4M	$713.6M	$599.0M
Total Assets	$1.894B	$1.853B	$1.637B
YoY Change	16.57%	13.23%	3.03%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$8.463M	$5.268M	$5.966M
YoY Change	14.8%	-11.7%	32.25%
Accrued Expenses	$168.6M	$265.1M	$240.5M
YoY Change	0.93%	10.2%	10.54%
Deferred Revenue		$4.723M
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$182.1M	$275.0M	$249.4M
YoY Change	3.0%	10.3%	11.09%
LONG-TERM LIABILITIES
Long-Term Debt	$20.00M	$30.00M	$0.00
YoY Change
Other Long-Term Liabilities	$12.96M	$12.38M	$0.00
YoY Change	-16.93%		-100.0%
Total Long-Term Liabilities	$12.96M	$12.38M	$0.00
YoY Change	-16.93%		-100.0%
TOTAL LIABILITIES
Total Short-Term Liabilities	$182.1M	$275.0M	$249.4M
Total Long-Term Liabilities	$12.96M	$12.38M	$0.00
Total Liabilities	$280.1M	$376.5M	$333.7M
YoY Change	6.99%	12.83%	11.64%
SHAREHOLDERS EQUITY
Retained Earnings	$544.9M	$467.5M	$384.0M
YoY Change	29.52%	21.73%	-4.68%
Common Stock	$1.087B	$1.029B	$957.1M
YoY Change	11.18%	7.55%	4.92%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.614B	$1.477B	$1.303B
YoY Change
Total Liabilities & Shareholders Equity	$1.894B	$1.853B	$1.637B
YoY Change	16.57%	13.23%	3.03%

Cashflow Statement

Concept	2018 Q1	2017 Q4	2016 Q4
OPERATING ACTIVITIES
Net Income	$139.8M	$122.1M	$88.61M
YoY Change	57.59%	37.84%	8.89%
Depreciation, Depletion And Amortization	$7.122M	$17.00M	$18.60M
YoY Change	4.74%	-8.6%	10.06%
Cash From Operating Activities	$104.2M	$143.5M	$144.8M
YoY Change	42.68%	-0.9%	23.76%
INVESTING ACTIVITIES
Capital Expenditures	$5.611M	-$17.70M	-$21.90M
YoY Change	75.07%	-19.18%	39.49%
Acquisitions
YoY Change
Other Investing Activities	$3.100M	-$6.500M	$7.400M
YoY Change		-187.84%	-237.04%
Cash From Investing Activities	-$15.38M	-$24.20M	-$14.50M
YoY Change	-39.33%	66.9%	-31.28%
FINANCING ACTIVITIES
Cash Dividend Paid	$47.18M
YoY Change	5.79%
Common Stock Issuance & Retirement, Net	$30.11M
YoY Change	-24.18%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-$87.29M	-59.90M	-54.40M
YoY Change	3.54%	10.11%	-9.78%
NET CHANGE
Cash From Operating Activities	$104.2M	143.5M	144.8M
Cash From Investing Activities	-$15.38M	-24.20M	-14.50M
Cash From Financing Activities	-$87.29M	-59.90M	-54.40M
Net Change In Cash	$4.054M	59.40M	75.90M
YoY Change	-111.81%	-21.74%	113.2%
FREE CASH FLOW
Cash From Operating Activities	$104.2M	$143.5M	$144.8M
Capital Expenditures	$5.611M	-$17.70M	-$21.90M
Free Cash Flow	$98.56M	$161.2M	$166.7M
YoY Change	41.19%	-3.3%	25.62%

Facts In Submission

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CY2017	dei	Document Period End Date DocumentPeriodEndDate	2017-12-31
CY2017	dei	Entity Central Index Key EntityCentralIndexKey	0000350894
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CY2017	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
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CY2017	dei	Trading Symbol TradingSymbol	SEIC
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CY2017	us-gaap	Gain Or Loss On Sale Of Stock In Subsidiary GainOrLossOnSaleOfStockInSubsidiary	0	USD
CY2016	us-gaap	Gain Or Loss On Sale Of Stock In Subsidiary GainOrLossOnSaleOfStockInSubsidiary	2791000	USD
CY2015	us-gaap	Gain Or Loss On Sale Of Stock In Subsidiary GainOrLossOnSaleOfStockInSubsidiary	2791000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	557039000	USD
CY2016	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	508485000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	500480000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	152650000	USD
CY2016	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	174668000	USD
CY2015	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	168825000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	404389000	USD
CY2016	us-gaap	Net Income Loss NetIncomeLoss	333817000	USD
CY2015	us-gaap	Net Income Loss NetIncomeLoss	331655000	USD
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.56
CY2016	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.07
CY2015	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.00
CY2017	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	158177000	shares
CY2016	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	161350000	shares
CY2015	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	165725000	shares
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.49
CY2016	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.03
CY2015	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.96
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	162269000	shares
CY2016	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	164431000	shares
CY2015	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	169598000	shares
CY2017	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.58
CY2016	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.54
CY2015	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.50
CY2017	us-gaap	Net Income Loss NetIncomeLoss	404389000	USD
CY2016	us-gaap	Net Income Loss NetIncomeLoss	333817000	USD
CY2015	us-gaap	Net Income Loss NetIncomeLoss	331655000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	17597000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-12131000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-14900000	USD
CY2017	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	190000	USD
CY2016	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-918000	USD
CY2015	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-1659000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-260000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-384000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-164000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	18047000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-12665000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-16395000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	422436000	USD
CY2016	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	321152000	USD
CY2015	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	315260000	USD
CY2017Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1476839000	USD
CY2016Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1303114000	USD
CY2015Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1289720000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	404389000	USD
CY2016	us-gaap	Net Income Loss NetIncomeLoss	333817000	USD
CY2015	us-gaap	Net Income Loss NetIncomeLoss	331655000	USD
CY2017	us-gaap	Depreciation Nonproduction DepreciationNonproduction	27311000	USD
CY2016	us-gaap	Depreciation Nonproduction DepreciationNonproduction	26440000	USD
CY2015	us-gaap	Depreciation Nonproduction DepreciationNonproduction	24044000	USD
CY2017	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	48275000	USD
CY2016	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	45392000	USD
CY2015	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	42630000	USD
CY2017	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	152550000	USD
CY2016	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	126103000	USD
CY2015	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	137057000	USD
CY2017	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	143517000	USD
CY2016	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	125224000	USD
CY2015	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	141767000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	36366000	USD
CY2016	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	16017000	USD
CY2015	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17312000	USD
CY2017	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	172000	USD
CY2016	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-126000	USD
CY2015	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-135000	USD
CY2017	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	21046000	USD
CY2016	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-4794000	USD
CY2015	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	1394000	USD
CY2017	us-gaap	Gain Or Loss On Sale Of Stock In Subsidiary GainOrLossOnSaleOfStockInSubsidiary	0	USD
CY2016	us-gaap	Gain Or Loss On Sale Of Stock In Subsidiary GainOrLossOnSaleOfStockInSubsidiary	2791000	USD
CY2015	us-gaap	Gain Or Loss On Sale Of Stock In Subsidiary GainOrLossOnSaleOfStockInSubsidiary	2791000	USD
CY2017	us-gaap	Gain Loss On Investments Excluding Other Than Temporary Impairments GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments	1269000	USD
CY2016	us-gaap	Gain Loss On Investments Excluding Other Than Temporary Impairments GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments	112000	USD
CY2015	us-gaap	Gain Loss On Investments Excluding Other Than Temporary Impairments GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments	-456000	USD
CY2017	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	0	USD
CY2016	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	-8984000	USD
CY2015	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	-16056000	USD
CY2017	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	10629000	USD
CY2016	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	0	USD
CY2015	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	0	USD
CY2017	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-2265000	USD
CY2016	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	3248000	USD
CY2015	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	1070000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	1489000	USD
CY2016	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	1917000	USD
CY2015	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-783000	USD
CY2017	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	0	USD
CY2016	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	0	USD
CY2015	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-6055000	USD
CY2017	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	2191000	USD
CY2016	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-390000	USD
CY2015	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	2440000	USD
CY2017	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	-5095000	USD
CY2016	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	13663000	USD
CY2015	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	-295000	USD
CY2017	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	52726000	USD
CY2016	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	4807000	USD
CY2015	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	28469000	USD
CY2017	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	3583000	USD
CY2016	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	1368000	USD
CY2015	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	8014000	USD
CY2017	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-909000	USD
CY2016	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	1455000	USD
CY2015	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-5441000	USD
CY2017	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	20992000	USD
CY2016	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	18851000	USD
CY2015	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	10498000	USD
CY2017	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	1180000	USD
CY2016	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	495000	USD
CY2015	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	636000	USD
CY2017	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	55509000	USD
CY2016	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	100403000	USD
CY2015	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	75861000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	459898000	USD
CY2016	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	434220000	USD
CY2015	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	407516000	USD
CY2017	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	0	USD
CY2016	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	-2000000	USD
CY2015	us-gaap	Increase Decrease In Restricted Cash IncreaseDecreaseInRestrictedCash	-301000	USD
CY2017	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	25525000	USD
CY2016	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	31397000	USD
CY2015	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	44465000	USD
CY2017	us-gaap	Payments For Software PaymentsForSoftware	61043000	USD
CY2016	us-gaap	Payments For Software PaymentsForSoftware	50392000	USD
CY2015	us-gaap	Payments For Software PaymentsForSoftware	29416000	USD
CY2017	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	69525000	USD
CY2016	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	73193000	USD
CY2015	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	52538000	USD
CY2017	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	65830000	USD
CY2016	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	54141000	USD
CY2015	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	38551000	USD
CY2017	seic	Sale Of Marketable Securities SaleOfMarketableSecurities	0	USD
CY2016	seic	Sale Of Marketable Securities SaleOfMarketableSecurities	15152000	USD
CY2015	seic	Sale Of Marketable Securities SaleOfMarketableSecurities	7761000	USD
CY2017	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	80234000	USD
CY2016	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2015	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2017	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	0	USD
CY2016	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	2791000	USD
CY2015	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	2791000	USD
CY2017	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	1805000	USD
CY2016	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-1313000	USD
CY2015	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	1000000	USD
CY2017	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-172302000	USD
CY2016	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-79585000	USD
CY2015	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-78015000	USD
CY2017	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	40000000	USD
CY2016	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	0	USD
CY2015	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	0	USD
CY2017	us-gaap	Repayments Of Long Term Lines Of Credit RepaymentsOfLongTermLinesOfCredit	10000000	USD
CY2016	us-gaap	Repayments Of Long Term Lines Of Credit RepaymentsOfLongTermLinesOfCredit	0	USD
CY2015	us-gaap	Repayments Of Long Term Lines Of Credit RepaymentsOfLongTermLinesOfCredit	0	USD
CY2017	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	248339000	USD
CY2016	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	292258000	USD
CY2015	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	291374000	USD
CY2017	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	53568000	USD
CY2016	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	48272000	USD
CY2015	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	65543000	USD
CY2017	us-gaap	Payments Of Dividends PaymentsOfDividends	88862000	USD
CY2016	us-gaap	Payments Of Dividends PaymentsOfDividends	84686000	USD
CY2015	us-gaap	Payments Of Dividends PaymentsOfDividends	80030000	USD
CY2017	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-253633000	USD
CY2016	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-328672000	USD
CY2015	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-305861000	USD
CY2017	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	14583000	USD
CY2016	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	-9923000	USD
CY2015	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	-11425000	USD
CY2017	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	48546000	USD
CY2016	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	16040000	USD
CY2015	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	12215000	USD
CY2016Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	695701000	USD
CY2015Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	679661000	USD
CY2014Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	667446000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	744247000	USD
CY2016Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	695701000	USD
CY2015Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	679661000	USD
CY2017	us-gaap	Interest Paid InterestPaid	699000	USD
CY2016	us-gaap	Interest Paid InterestPaid	531000	USD
CY2015	us-gaap	Interest Paid InterestPaid	460000	USD
CY2017	us-gaap	Income Taxes Paid IncomeTaxesPaid	165049000	USD
CY2016	us-gaap	Income Taxes Paid IncomeTaxesPaid	157255000	USD
CY2015	us-gaap	Income Taxes Paid IncomeTaxesPaid	159605000	USD
CY2017Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	47179000	USD
CY2016Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	44596000	USD
CY2015Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	42625000	USD
CY2017	us-gaap	Use Of Estimates UseOfEstimates	Management’s Use of EstimatesThe preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S. GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
CY2017	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	Concentration of Credit RiskFinancial instruments which potentially expose the Company to concentrations of credit risk consist primarily of cash equivalents and trade receivables. Cash equivalents are principally invested in short-term money market funds or placed with major banks and high-credit qualified financial institutions. Cash deposits maintained with institutions are in excess of federally insured limits. Concentrations of credit risk with respect to the Company's receivables are limited due to the large number of clients and their dispersion across geographic areas. No single group or customer represents greater than ten percent of total accounts receivable.
CY2017	us-gaap	Capitalized Computer Software Additions CapitalizedComputerSoftwareAdditions	61043000	USD
CY2016	us-gaap	Capitalized Computer Software Additions CapitalizedComputerSoftwareAdditions	50392000	USD
CY2015	us-gaap	Capitalized Computer Software Additions CapitalizedComputerSoftwareAdditions	29416000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	43717000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	43717000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	43717000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	43439000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	29556000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	404389000	USD
CY2016	us-gaap	Net Income Loss NetIncomeLoss	333817000	USD
CY2015	us-gaap	Net Income Loss NetIncomeLoss	331655000	USD
CY2017	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	158177000	shares
CY2016	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	161350000	shares
CY2015	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	165725000	shares
CY2017	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	4092000	shares
CY2016	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	3081000	shares
CY2015	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	3873000	shares
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	162269000	shares
CY2016	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	164431000	shares
CY2015	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	169598000	shares
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.56
CY2016	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.07
CY2015	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.00
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.49
CY2016	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.03
CY2015	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.96
CY2017	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	5196000	shares
CY2016	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	10632000	shares
CY2015	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	10730000	shares
CY2017	us-gaap	Antidilutive Securities Excluded From Computation Of Net Income Per Outstanding Unit Amount AntidilutiveSecuritiesExcludedFromComputationOfNetIncomePerOutstandingUnitAmount	45.49
CY2016	us-gaap	Antidilutive Securities Excluded From Computation Of Net Income Per Outstanding Unit Amount AntidilutiveSecuritiesExcludedFromComputationOfNetIncomePerOutstandingUnitAmount	35.02
CY2015	us-gaap	Antidilutive Securities Excluded From Computation Of Net Income Per Outstanding Unit Amount AntidilutiveSecuritiesExcludedFromComputationOfNetIncomePerOutstandingUnitAmount	33.99
CY2017	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	ReclassificationsCertain prior year amounts have been reclassified to conform to current year presentation.
CY2017Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	146428000	USD
CY2016Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	146190000	USD
CY2017Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	76760000	USD
CY2016Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	48683000	USD
CY2017Q4	us-gaap	Unbilled Contracts Receivable UnbilledContractsReceivable	194331000	USD
CY2016Q4	us-gaap	Unbilled Contracts Receivable UnbilledContractsReceivable	168971000	USD
CY2017Q4	us-gaap	Other Receivables Gross Current OtherReceivablesGrossCurrent	12310000	USD
CY2016Q4	us-gaap	Other Receivables Gross Current OtherReceivablesGrossCurrent	10826000	USD
CY2017Q4	seic	Receivables Gross Current ReceivablesGrossCurrent	283401000	USD
CY2016Q4	seic	Receivables Gross Current ReceivablesGrossCurrent	228480000	USD
CY2017Q4	seic	Allowancefor Doubtful Receivables AllowanceforDoubtfulReceivables	695000	USD
CY2016Q4	seic	Allowancefor Doubtful Receivables AllowanceforDoubtfulReceivables	523000	USD
CY2017Q4	us-gaap	Receivables Net Current ReceivablesNetCurrent	282706000	USD
CY2016Q4	us-gaap	Receivables Net Current ReceivablesNetCurrent	227957000	USD
CY2017Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	456383000	USD
CY2016Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	431512000	USD
CY2017Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	309955000	USD
CY2016Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	285322000	USD
CY2017	us-gaap	Depreciation Nonproduction DepreciationNonproduction	27311000	USD
CY2016	us-gaap	Depreciation Nonproduction DepreciationNonproduction	26440000	USD
CY2015	us-gaap	Depreciation Nonproduction DepreciationNonproduction	24044000	USD
CY2017	us-gaap	Other Amortization Of Deferred Charges OtherAmortizationOfDeferredCharges	218000	USD
CY2016	us-gaap	Other Amortization Of Deferred Charges OtherAmortizationOfDeferredCharges	345000	USD
CY2015	us-gaap	Other Amortization Of Deferred Charges OtherAmortizationOfDeferredCharges	229000	USD
CY2017Q4	us-gaap	Accrued Salaries Current AccruedSalariesCurrent	88960000	USD
CY2016Q4	us-gaap	Accrued Salaries Current AccruedSalariesCurrent	79735000	USD
CY2017Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	29658000	USD
CY2016Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	24428000	USD
CY2017Q4	seic	Accrued Sub Advisory Distribution And Other Asset Management Fees Current AccruedSubAdvisoryDistributionAndOtherAssetManagementFeesCurrent	42365000	USD
CY2016Q4	seic	Accrued Sub Advisory Distribution And Other Asset Management Fees Current AccruedSubAdvisoryDistributionAndOtherAssetManagementFeesCurrent	41666000	USD
CY2017Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	47179000	USD
CY2016Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	44596000	USD
CY2017Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	56896000	USD
CY2016Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	50100000	USD
CY2017Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	265058000	USD
CY2016Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	240525000	USD
CY2017Q4	us-gaap	Available For Sale Securities Equity Securities AvailableForSaleSecuritiesEquitySecurities	11250000	USD
CY2017Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	76733000	USD
CY2017Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	21526000	USD
CY2017Q4	us-gaap	Alternative Investments Fair Value Disclosure AlternativeInvestmentsFairValueDisclosure	6034000	USD
CY2017Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	115543000	USD
CY2016Q4	us-gaap	Available For Sale Securities Equity Securities AvailableForSaleSecuritiesEquitySecurities	9581000	USD
CY2016Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	74452000	USD
CY2016Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	21339000	USD
CY2016Q4	us-gaap	Alternative Investments Fair Value Disclosure AlternativeInvestmentsFairValueDisclosure	4858000	USD
CY2016Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	110230000	USD
CY2017Q4	us-gaap	Available For Sale Securities Amortized Cost AvailableForSaleSecuritiesAmortizedCost	88570000	USD
CY2017Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	568000	USD
CY2017Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	1155000	USD
CY2017Q4	us-gaap	Available For Sale Securities AvailableForSaleSecurities	87983000	USD
CY2016Q4	us-gaap	Available For Sale Securities Amortized Cost AvailableForSaleSecuritiesAmortizedCost	85168000	USD
CY2016Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	252000	USD
CY2016Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	1387000	USD
CY2016Q4	us-gaap	Available For Sale Securities AvailableForSaleSecurities	84033000	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-386000	USD
CY2017Q4	seic	Accumulated Other Comprehensive Income Loss Availableforsale Securities Adjustment Tax AccumulatedOtherComprehensiveIncomeLossAvailableforsaleSecuritiesAdjustmentTax	-201000	USD
CY2016Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-836000	USD
CY2016Q4	seic	Accumulated Other Comprehensive Income Loss Availableforsale Securities Adjustment Tax AccumulatedOtherComprehensiveIncomeLossAvailableforsaleSecuritiesAdjustmentTax	-299000	USD
CY2017	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	529000	USD
CY2017	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	888000	USD
CY2016	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	284000	USD
CY2016	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	869000	USD
CY2015	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	489000	USD
CY2015	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	729000	USD
CY2017Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	21526000	USD
CY2016Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	21339000	USD
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	16.78
CY2016	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	12.43
CY2015	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	12.16
CY2017	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y
CY2016	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y
CY2015	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P5Y6M29D
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.2258
CY2016	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.2544
CY2015	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.2386
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0082
CY2016	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0110
CY2015	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0100
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0229
CY2016	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0218
CY2015	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0190
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	36366000	USD
CY2016	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	16017000	USD
CY2015	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17312000	USD
CY2017	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	7891000	USD
CY2016	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	5612000	USD
CY2015	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	6107000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	28475000	USD
CY2016	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	10405000	USD
CY2015	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	11205000	USD
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Accelerated Compensation Cost ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost	11206000	USD
CY2017Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Number Of Shares SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares	6088000	shares
CY2017Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	62070000	USD
CY2017	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P2Y3M18D
CY2014Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	20461000	shares
CY2014Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	25.26
CY2015	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	2005000	shares
CY2015	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	53.34
CY2015	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	2927000	shares
CY2015	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	21.44
CY2015	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	302000	shares
CY2015	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	28.97
CY2015Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	19237000	shares
CY2015Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	28.71
CY2016	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	2310000	shares
CY2016	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	49.57
CY2016	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	1809000	shares
CY2016	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	24.82
CY2016	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	1669000	shares
CY2016	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	30.86
CY2016Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	18069000	shares
CY2016Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	31.57
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	2057000	shares
CY2017	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	69.87
CY2017	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	2370000	shares
CY2017	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	21.22
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	1044000	shares
CY2017	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	33.42
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	16712000	shares
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	37.63
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	10624000	shares
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	28.99
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	24108000	shares
CY2016Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	6692000	shares
CY2015Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	8508000	shares
CY2017	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P6Y3M18D
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	83628000	USD
CY2016	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	41607000	USD
CY2017Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	455528000	USD
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	572024000	USD
CY2017Q4	us-gaap	Share Price SharePrice	71.86
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	16712000	shares
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	10624000	shares
CY2017Q4	seic	Rights Agreement Conversion Rateof Rights Per Common Share RightsAgreementConversionRateofRightsPerCommonShare	1
CY2017Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.05
CY2017Q4	seic	Rights Agreement Securities Purchase Price Per Unit RightsAgreementSecuritiesPurchasePricePerUnit	150.00
CY2017	seic	Rights Agreement Numberof Days Following Public Announcement Rights Become Exercisable RightsAgreementNumberofDaysFollowingPublicAnnouncementRightsBecomeExercisable	P10D
CY2017Q4	seic	Rights Agreement Triggering Event Voting Interest RightsAgreementTriggeringEventVotingInterest	0.20
CY2017Q4	seic	Rights Agreement Triggering Event Voting Interest RightsAgreementTriggeringEventVotingInterest	0.20
CY2017	seic	Rights Agreement Percentageof Rights Received After Surrender RightsAgreementPercentageofRightsReceivedAfterSurrender	0.50
CY2017	seic	Rights Agreement Numberof Days Following Public Announcement Nonvoting Rights Become Redeemable RightsAgreementNumberofDaysFollowingPublicAnnouncementNonvotingRightsBecomeRedeemable	P10D
CY2017Q4	seic	Rights Agreement Purchase Price Per Right RightsAgreementPurchasePricePerRight	0.01
CY2017Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2017Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.30
CY2017	us-gaap	Dividends Common Stock DividendsCommonStock	91444000	USD
CY2016	us-gaap	Dividends Common Stock DividendsCommonStock	86657000	USD
CY2015	us-gaap	Dividends Common Stock DividendsCommonStock	82478000	USD
CY2014Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-8895000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-16559000	USD
CY2015	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-164000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-16395000	USD
CY2015Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-25290000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-13049000	USD
CY2016	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-384000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-12665000	USD
CY2016Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-37955000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	17787000	USD
CY2017	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-260000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	18047000	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-19908000	USD
CY2017	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	10929000	USD
CY2016	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	9665000	USD
CY2015	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	9162000	USD
CY2017	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	32619000	USD
CY2016	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	28016000	USD
CY2015	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	25074000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	10046000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	9427000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	7413000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	7082000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	29171000	USD
CY2017Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	63139000	USD
CY2017	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	154776000	USD
CY2016	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	158411000	USD
CY2015	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	159774000	USD
CY2017	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	11645000	USD
CY2016	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	10500000	USD
CY2015	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	7756000	USD
CY2017	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	8002000	USD
CY2016	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	5137000	USD
CY2015	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	5224000	USD
CY2017	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	174423000	USD
CY2016	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	174048000	USD
CY2015	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	172754000	USD
CY2017	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-26350000	USD
CY2016	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	788000	USD
CY2015	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-5343000	USD
CY2017	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1378000	USD
CY2016	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-168000	USD
CY2015	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1414000	USD
CY2017	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	3199000	USD
CY2016	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	0	USD
CY2015	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	0	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-21773000	USD
CY2016	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	620000	USD
CY2015	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-3929000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	152650000	USD
CY2016	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	174668000	USD
CY2015	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	168825000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	523044000	USD
CY2016	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	481760000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	472384000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	33995000	USD
CY2016	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	26725000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	28096000	USD
CY2017	seic	Income Lossfrom Continuing Operationsbefore Income Taxes IncomeLossfromContinuingOperationsbeforeIncomeTaxes	557039000	USD
CY2016	seic	Income Lossfrom Continuing Operationsbefore Income Taxes IncomeLossfromContinuingOperationsbeforeIncomeTaxes	508485000	USD
CY2015	seic	Income Lossfrom Continuing Operationsbefore Income Taxes IncomeLossfromContinuingOperationsbeforeIncomeTaxes	500480000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2016	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2015	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2017	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.013
CY2016	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.013
CY2015	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.016
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.011
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.008
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.012
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.039
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	-0.049
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0.026
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.009
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.008
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.006
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.005
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.006
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.006
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	0
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	0
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	-0.008
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.002
CY2016	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.002
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.003
CY2017	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.274
CY2016	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.343
CY2015	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.337
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2017Q4	seic	Estimated Liability For One Time Transition Tax Under Tax Act EstimatedLiabilityForOneTimeTransitionTaxUnderTaxAct	11544000	USD
CY2017Q4	seic	Estimated Liability For One Time Transition Tax Under Tax Act Short Term EstimatedLiabilityForOneTimeTransitionTaxUnderTaxActShortTerm	915000	USD
CY2017Q4	seic	Estimated Liability For One Time Transition Tax Under Tax Act Long Term EstimatedLiabilityForOneTimeTransitionTaxUnderTaxActLongTerm	10629000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	3199000	USD
CY2017	us-gaap	Income Tax Expense Benefit Continuing Operations Adjustment Of Deferred Tax Asset Liability IncomeTaxExpenseBenefitContinuingOperationsAdjustmentOfDeferredTaxAssetLiability	-27153000	USD
CY2017	seic	Expense From One Time Transition Tax Under Tax Act And Withholding Tax ExpenseFromOneTimeTransitionTaxUnderTaxActAndWithholdingTax	14743000	USD
CY2017Q4	seic	Net Income Tax Benefit From Enactmentof Tax Act NetIncomeTaxBenefitFromEnactmentofTaxAct	12410000	USD
CY2017Q4	seic	Net Income Tax Benefit From Enactment Of Tax Act Per Diluted Share NetIncomeTaxBenefitFromEnactmentOfTaxActPerDilutedShare	0.08
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	24725000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	33459000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	71236000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	20049000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Equity Method Investments DeferredTaxAssetsEquityMethodInvestments	4191000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Equity Method Investments DeferredTaxAssetsEquityMethodInvestments	6165000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Contingencies DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsContingencies	1918000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Contingencies DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsContingencies	3647000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	2631000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	5022000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	273000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	813000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Gross Noncurrent DeferredTaxAssetsGrossNoncurrent	104974000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Gross Noncurrent DeferredTaxAssetsGrossNoncurrent	69155000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	68469000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	17922000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Net Noncurrent DeferredTaxAssetsNetNoncurrent	36505000	USD
CY2016Q4	us-gaap	Deferred Tax Assets Net Noncurrent DeferredTaxAssetsNetNoncurrent	51233000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Capitalized Software DeferredTaxLiabilitiesDeferredExpenseCapitalizedSoftware	70575000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Capitalized Software DeferredTaxLiabilitiesDeferredExpenseCapitalizedSoftware	107897000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	3182000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	5190000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	3549000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	4597000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Goodwill DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill	1001000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Goodwill DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill	0	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	3199000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	0	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	704000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	1115000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Gross Noncurrent DeferredTaxLiabilitiesGrossNoncurrent	82210000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Gross Noncurrent DeferredTaxLiabilitiesGrossNoncurrent	118799000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	45705000	USD
CY2016Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	67566000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	14480000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	13737000	USD
CY2017	seic	Unrecognized Tax Benefits Reductions Resulting From Lapseof Applicable Statuteof Limitations1 UnrecognizedTaxBenefitsReductionsResultingFromLapseofApplicableStatuteofLimitations1	5846000	USD
CY2016Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	17287000	USD
CY2015Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	14517000	USD
CY2014Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	14018000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	3180000	USD
CY2016	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	3756000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1954000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	211000	USD
CY2016	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	1762000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	297000	USD
CY2017	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	352000	USD
CY2016	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	378000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2017	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	5846000	USD
CY2016	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	2370000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	1752000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	14480000	USD
CY2016Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	17287000	USD
CY2015Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	14517000	USD
CY2017	us-gaap	Income Tax Examination Penalties And Interest Expense IncomeTaxExaminationPenaltiesAndInterestExpense	1175000	USD
CY2016	us-gaap	Income Tax Examination Penalties And Interest Expense IncomeTaxExaminationPenaltiesAndInterestExpense	1227000	USD
CY2015	us-gaap	Income Tax Examination Penalties And Interest Expense IncomeTaxExaminationPenaltiesAndInterestExpense	1391000	USD
CY2017	us-gaap	Revenues Revenues	1526552000	USD
CY2017	us-gaap	Operating Costs And Expenses OperatingCostsAndExpenses	1065774000	USD
CY2017	us-gaap	Gross Profit GrossProfit	460778000	USD
CY2016	us-gaap	Revenues Revenues	1401545000	USD
CY2016	us-gaap	Operating Costs And Expenses OperatingCostsAndExpenses	966534000	USD
CY2016	us-gaap	Gross Profit GrossProfit	435011000	USD
CY2016	us-gaap	Disposal Group Not Discontinued Operation Gain Loss On Disposal DisposalGroupNotDiscontinuedOperationGainLossOnDisposal	2791000	USD
CY2016	seic	Segment Profit Loss SegmentProfitLoss	437802000	USD
CY2015	us-gaap	Revenues Revenues	1334208000	USD
CY2015	us-gaap	Operating Costs And Expenses OperatingCostsAndExpenses	921544000	USD
CY2015	us-gaap	Gross Profit GrossProfit	412664000	USD
CY2015	us-gaap	Disposal Group Not Discontinued Operation Gain Loss On Disposal DisposalGroupNotDiscontinuedOperationGainLossOnDisposal	2791000	USD
CY2015	seic	Segment Profit Loss SegmentProfitLoss	415455000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	396944000	USD
CY2016	us-gaap	Operating Income Loss OperatingIncomeLoss	375694000	USD
CY2015	us-gaap	Operating Income Loss OperatingIncomeLoss	358213000	USD
CY2017	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	86568000	USD
CY2016	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	81789000	USD
CY2015	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	73881000	USD
CY2017	us-gaap	Depreciation Depreciation	27311000	USD
CY2016	us-gaap	Depreciation Depreciation	26440000	USD
CY2015	us-gaap	Depreciation Depreciation	24044000	USD
CY2017	us-gaap	Adjustment For Amortization AdjustmentForAmortization	48275000	USD
CY2016	us-gaap	Adjustment For Amortization AdjustmentForAmortization	45392000	USD
CY2015	us-gaap	Adjustment For Amortization AdjustmentForAmortization	42630000	USD
CY2017Q4	us-gaap	Assets Assets	1853369000	USD
CY2016Q4	us-gaap	Assets Assets	1636823000	USD
CY2017	us-gaap	Revenues Revenues	1526552000	USD
CY2016	us-gaap	Revenues Revenues	1401545000	USD
CY2015	us-gaap	Revenues Revenues	1334208000	USD
CY2017Q4	us-gaap	Assets Assets	1853369000	USD
CY2016Q4	us-gaap	Assets Assets	1636823000	USD
CY2016Q4	us-gaap	Revenues Revenues	368810000	USD
CY2016Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	119638000	USD
CY2016Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	124904000	USD
CY2016Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	130890000	USD
CY2016Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	133053000	USD
CY2016Q1	us-gaap	Profit Loss ProfitLoss	77497000	USD
CY2017Q3	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Property Plant And Equipment BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment	776000	USD
CY2017Q1	us-gaap	Revenues Revenues	359984000	USD
CY2017Q2	us-gaap	Revenues Revenues	372331000	USD
CY2017Q3	us-gaap	Revenues Revenues	386018000	USD
CY2017Q4	us-gaap	Revenues Revenues	408219000	USD
CY2017Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	128660000	USD
CY2017Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	135158000	USD
CY2017Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	140769000	USD
CY2017Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	152452000	USD
CY2017Q1	us-gaap	Profit Loss ProfitLoss	88737000	USD
CY2017Q2	us-gaap	Profit Loss ProfitLoss	91769000	USD
CY2017Q3	us-gaap	Profit Loss ProfitLoss	101739000	USD
CY2017Q4	us-gaap	Profit Loss ProfitLoss	122144000	USD
CY2017Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.56
CY2017Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.58
CY2017Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.64
CY2017Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.78
CY2017Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.55
CY2017Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.57
CY2017Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.63
CY2017Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.75
CY2017Q1	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.310
CY2017Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.321
CY2017Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.277
CY2017Q4	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.199
CY2017Q4	seic	Net Income Tax Benefit From Enactmentof Tax Act NetIncomeTaxBenefitFromEnactmentofTaxAct	12410000	USD
CY2017Q4	seic	Net Income Tax Benefit From Enactment Of Tax Act Per Diluted Share NetIncomeTaxBenefitFromEnactmentOfTaxActPerDilutedShare	0.08
CY2016Q1	us-gaap	Revenues Revenues	334263000	USD
CY2016Q2	us-gaap	Revenues Revenues	343831000	USD
CY2016Q3	us-gaap	Revenues Revenues	354641000	USD
CY2016Q2	us-gaap	Profit Loss ProfitLoss	81005000	USD
CY2016Q3	us-gaap	Profit Loss ProfitLoss	86704000	USD
CY2016Q4	us-gaap	Profit Loss ProfitLoss	88611000	USD
CY2016Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.48
CY2016Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.50
CY2016Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.54
CY2016Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.55
CY2016Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.47
CY2016Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.49
CY2016Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.53
CY2016Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.55
CY2016Q1	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.352
CY2016Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.352
CY2016Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.338
CY2016Q4	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.334

Files In Submission

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$SEIC
SEI INVESTMENTS CO Stock $seic

2018 Q1 Form 10-K Financial Statement

#000035089418000011 Filed on February 22, 2018

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SEIC SEI INVESTMENTS CO Stock $seic

2018 Q1 Form 10-K Financial Statement

#000035089418000011 Filed on February 22, 2018

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SEIC
SEI INVESTMENTS CO Stock $seic