$SEIC
SEI INVESTMENTS CO Stock $seic

$seic Overview Financials Valuation SEC Filings Company Website

2019 Q1 Form 10-K Financial Statement

#000035089419000012 Filed on February 25, 2019

Income Statement

Concept	2019 Q1	2018 Q4	2018
Revenue	$400.8M	$405.1M	$1.624B
YoY Change	-1.18%	-0.77%	6.39%
Cost Of Revenue	$68.10M	$71.50M	$283.8M
YoY Change	-4.76%	-8.92%	-5.62%
Gross Profit	$123.6M	$333.5M	$507.6M
YoY Change	-5.84%	1.15%	10.17%
Gross Profit Margin	30.84%	82.33%	31.26%
Selling, General & Admin	$209.1M	$210.8M	$820.7M
YoY Change	5.18%	2.43%	8.93%
% of Gross Profit	169.18%	63.21%	161.67%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$7.331M	$19.80M	$28.79M
YoY Change	2.93%	16.47%	5.42%
% of Gross Profit	5.93%	5.94%	5.67%
Operating Expenses	$229.2M	$230.6M	$898.4M
YoY Change	5.23%	3.5%	8.38%
Operating Profit	$103.6M	$102.9M	$442.0M
YoY Change	-10.97%	-3.74%	11.35%
Interest Expense	$157.0K	$40.60M	$645.0K
YoY Change	-38.91%	-10.77%	-17.41%
% of Operating Profit	0.15%	39.46%	0.15%
Other Income/Expense, Net
YoY Change
Pretax Income	$146.3M	$143.6M	$614.2M
YoY Change	-7.87%	-5.81%	10.26%
Income Tax	$32.28M	$28.80M	$108.3M
% Of Pretax Income	22.07%	20.06%	17.64%
Net Earnings	$114.0M	$116.0M	$505.9M
YoY Change	-18.49%	-5.0%	25.09%
Net Earnings / Revenue	28.44%	28.65%	31.15%
Basic Earnings Per Share	$0.74	$0.75	$3.23
Diluted Earnings Per Share	$0.73	$0.73	$3.14
COMMON SHARES
Basic Shares Outstanding	153.7M shares	155.5M shares
Diluted Shares Outstanding	156.5M shares		161.2M shares

Balance Sheet

Concept	2019 Q1	2018 Q4	2018
SHORT-TERM ASSETS
Cash & Short-Term Investments	$702.8M	$785.4M	$785.4M
YoY Change	-8.72%	2.56%	2.56%
Cash & Equivalents	$669.3M	$754.5M	$754.5M
Short-Term Investments	$33.40M	$30.90M	$30.90M
Other Short-Term Assets	$35.05M	$36.68M	$40.20M
YoY Change	0.94%	17.71%	15.85%
Inventory
Prepaid Expenses
Receivables	$373.0M	$315.3M	$351.5M
Other Receivables	$13.30M	$13.70M	$13.70M
Total Short-Term Assets	$1.128B	$1.191B	$1.191B
YoY Change	-3.73%	4.47%	4.47%
LONG-TERM ASSETS
Property, Plant & Equipment	$146.8M	$145.9M	$145.9M
YoY Change	1.01%	-0.39%	-0.34%
Goodwill	$64.49M	$64.49M
YoY Change	21.7%	21.7%
Intangibles	$30.75M	$31.67M
YoY Change	10.6%	10.82%
Long-Term Investments	$171.6M	$169.1M	$169.1M
YoY Change	19.92%	10.16%	10.16%
Other Assets	$32.88M	$34.16M	$60.20M
YoY Change	79.35%	80.87%	177.42%
Total Long-Term Assets	$825.5M	$780.9M	$780.9M
YoY Change	14.27%	9.43%	9.43%
TOTAL ASSETS
Total Short-Term Assets	$1.128B	$1.191B	$1.191B
Total Long-Term Assets	$825.5M	$780.9M	$780.9M
Total Assets	$1.953B	$1.972B	$1.972B
YoY Change	3.14%	6.38%	6.38%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$5.242M	$10.92M	$10.90M
YoY Change	-38.06%	107.29%	105.66%
Accrued Expenses	$173.9M	$279.6M	$228.9M
YoY Change	3.11%	5.5%	30.43%
Deferred Revenue	$4.979M	$5.154M
YoY Change		9.13%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$192.5M	$295.7M	$295.7M
YoY Change	5.74%	7.51%	7.53%
LONG-TERM LIABILITIES
Long-Term Debt	$0.00	$0.00	$0.00
YoY Change	-100.0%	-100.0%	-100.0%
Other Long-Term Liabilities	$24.49M	$24.22M	$25.00M
YoY Change	89.0%	95.6%	8.7%
Total Long-Term Liabilities	$24.49M	$24.22M	$25.00M
YoY Change	89.0%	95.6%	-52.83%
TOTAL LIABILITIES
Total Short-Term Liabilities	$192.5M	$295.7M	$295.7M
Total Long-Term Liabilities	$24.49M	$24.22M	$25.00M
Total Liabilities	$316.6M	$378.5M	$378.5M
YoY Change	13.04%	0.53%	0.53%
SHAREHOLDERS EQUITY
Retained Earnings	$552.4M	$518.0M
YoY Change	1.37%	10.8%
Common Stock	$1.113B	$1.108B
YoY Change	2.39%	7.67%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.637B	$1.593B	$1.593B
YoY Change
Total Liabilities & Shareholders Equity	$1.953B	$1.972B	$1.972B
YoY Change	3.14%	6.38%	6.38%

Cashflow Statement

Concept	2019 Q1	2018 Q4	2018
OPERATING ACTIVITIES
Net Income	$114.0M	$116.0M	$505.9M
YoY Change	-18.49%	-5.0%	25.09%
Depreciation, Depletion And Amortization	$7.331M	$19.80M	$28.79M
YoY Change	2.93%	16.47%	5.42%
Cash From Operating Activities	$59.90M	$170.5M	$588.4M
YoY Change	-42.5%	18.82%	27.94%
INVESTING ACTIVITIES
Capital Expenditures	$7.317M	-$18.30M	$29.10M
YoY Change	30.4%	3.39%	13.99%
Acquisitions			$5.794M
YoY Change			-92.78%
Other Investing Activities	$0.00	-$27.70M	$8.676M
YoY Change	-100.0%	326.15%	380.66%
Cash From Investing Activities	-$15.73M	-$46.00M	-$123.4M
YoY Change	2.28%	90.08%	-28.4%
FINANCING ACTIVITIES
Cash Dividend Paid	$50.76M		$94.32M
YoY Change	7.59%		6.14%
Common Stock Issuance & Retirement, Net	$81.88M		$319.4M
YoY Change	171.99%		63.99%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-$132.6M	-107.5M	-$443.7M
YoY Change	51.97%	79.47%	74.95%
NET CHANGE
Cash From Operating Activities	$59.90M	170.5M	$588.4M
Cash From Investing Activities	-$15.73M	-46.00M	-$123.4M
Cash From Financing Activities	-$132.6M	-107.5M	-$443.7M
Net Change In Cash	-$85.20M	17.00M	$10.29M
YoY Change	-2201.6%	-71.38%	-78.81%
FREE CASH FLOW
Cash From Operating Activities	$59.90M	$170.5M	$588.4M
Capital Expenditures	$7.317M	-$18.30M	$29.10M
Free Cash Flow	$52.58M	$188.8M	$559.3M
YoY Change	-46.65%	17.12%	28.76%

Facts In Submission

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CY2018	us-gaap	Interest Expense InterestExpense	645000	USD
CY2017	us-gaap	Interest Expense InterestExpense	781000	USD
CY2016	us-gaap	Interest Expense InterestExpense	531000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	159791000	USD
CY2016	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	126103000	USD
CY2016	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-12665000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	492776000	USD
CY2018	us-gaap	Gain Or Loss On Sale Of Stock In Subsidiary GainOrLossOnSaleOfStockInSubsidiary	0	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
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	614206000	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
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	108338000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	152650000	USD
CY2016	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	174668000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	505868000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	404389000	USD
CY2016	us-gaap	Net Income Loss NetIncomeLoss	333817000	USD
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.23
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.56
CY2016	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.07
CY2018	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	156579000	shares
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
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.14
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.49
CY2016	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.03
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	161232000	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
CY2018	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.63
CY2017	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.58
CY2016	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.54
CY2018	us-gaap	Net Income Loss NetIncomeLoss	505868000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	404389000	USD
CY2016	us-gaap	Net Income Loss NetIncomeLoss	333817000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-12065000	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
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-1088000	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
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-61000	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
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13092000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	18047000	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
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1593147000	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
CY2018	us-gaap	Net Income Loss NetIncomeLoss	505868000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	404389000	USD
CY2016	us-gaap	Net Income Loss NetIncomeLoss	333817000	USD
CY2018	us-gaap	Depreciation Nonproduction DepreciationNonproduction	28792000	USD
CY2017	us-gaap	Depreciation Nonproduction DepreciationNonproduction	27311000	USD
CY2016	us-gaap	Depreciation Nonproduction DepreciationNonproduction	26440000	USD
CY2018	us-gaap	Amortization Of Deferred Charges AmortizationOfDeferredCharges	48895000	USD
CY2017	us-gaap	Amortization Of Deferred Charges AmortizationOfDeferredCharges	48275000	USD
CY2016	us-gaap	Amortization Of Deferred Charges AmortizationOfDeferredCharges	45392000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	159791000	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
CY2018	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	166941000	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
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	23805000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	36366000	USD
CY2016	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	16017000	USD
CY2018	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	23000	USD
CY2017	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	172000	USD
CY2016	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-126000	USD
CY2018	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-5998000	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
CY2018	us-gaap	Gain Loss On Investments Excluding Other Than Temporary Impairments GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments	-325000	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
CY2018	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	-9826000	USD
CY2017	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	10629000	USD
CY2016	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	0	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	145000	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
CY2018	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	4785000	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
CY2018	seic	Capitalized Contract Costs Net Of Amortization CapitalizedContractCostsNetOfAmortization	5366000	USD
CY2017	seic	Capitalized Contract Costs Net Of Amortization CapitalizedContractCostsNetOfAmortization	0	USD
CY2016	seic	Capitalized Contract Costs Net Of Amortization CapitalizedContractCostsNetOfAmortization	0	USD
CY2018	us-gaap	Gain Or Loss On Sale Of Stock In Subsidiary GainOrLossOnSaleOfStockInSubsidiary	0	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
CY2018	us-gaap	Excess Tax Benefit From Share Based Compensation Operating Activities ExcessTaxBenefitFromShareBasedCompensationOperatingActivities	0	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
CY2018	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	294000	USD
CY2017	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	2186000	USD
CY2016	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-390000	USD
CY2018	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	-6797000	USD
CY2017	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	-5095000	USD
CY2016	us-gaap	Increase Decrease In Other Receivables IncreaseDecreaseInOtherReceivables	13663000	USD
CY2018	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	32652000	USD
CY2017	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	52726000	USD
CY2016	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	4807000	USD
CY2018	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	5518000	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
CY2018	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	5652000	USD
CY2017	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-909000	USD
CY2016	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	1455000	USD
CY2018	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	13079000	USD
CY2017	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	20992000	USD
CY2016	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	18851000	USD
CY2018	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	313000	USD
CY2017	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	1180000	USD
CY2016	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	495000	USD
CY2018	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	82533000	USD
CY2017	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	55514000	USD
CY2016	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	100403000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	588401000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	459903000	USD
CY2016	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	434220000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	29095000	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
CY2018	us-gaap	Payments For Software PaymentsForSoftware	44221000	USD
CY2017	us-gaap	Payments For Software PaymentsForSoftware	61043000	USD
CY2016	us-gaap	Payments For Software PaymentsForSoftware	50392000	USD
CY2018	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	203460000	USD
CY2017	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	69525000	USD
CY2016	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	73193000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	167876000	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
CY2018	seic	Sale Of Marketable Securities SaleOfMarketableSecurities	0	USD
CY2017	seic	Sale Of Marketable Securities SaleOfMarketableSecurities	0	USD
CY2016	seic	Sale Of Marketable Securities SaleOfMarketableSecurities	15152000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	5794000	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
CY2018	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	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
CY2018	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	8676000	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
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-123370000	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	-81585000	USD
CY2018	us-gaap	Repayments Of Long Term Lines Of Credit RepaymentsOfLongTermLinesOfCredit	30000000	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
CY2018	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	0	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
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	407384000	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
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	87982000	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
CY2018	us-gaap	Payments Of Dividends PaymentsOfDividends	94318000	USD
CY2017	us-gaap	Payments Of Dividends PaymentsOfDividends	88862000	USD
CY2016	us-gaap	Payments Of Dividends PaymentsOfDividends	84686000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-443720000	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
CY2018	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-11024000	USD
CY2017	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	14583000	USD
CY2016	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-9923000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	10287000	USD
CY2017	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	48551000	USD
CY2016	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	14040000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	747752000	USD
CY2016Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	699201000	USD
CY2015Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	685161000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	758039000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	747752000	USD
CY2016Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	699201000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	806000	USD
CY2017	us-gaap	Interest Paid Net InterestPaidNet	699000	USD
CY2016	us-gaap	Interest Paid Net InterestPaidNet	531000	USD
CY2018	us-gaap	Income Taxes Paid IncomeTaxesPaid	110203000	USD
CY2017	us-gaap	Income Taxes Paid IncomeTaxesPaid	165049000	USD
CY2016	us-gaap	Income Taxes Paid IncomeTaxesPaid	157255000	USD
CY2018Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	50761000	USD
CY2017Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	47179000	USD
CY2016Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	44596000	USD
CY2018	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.
CY2018	seic	Expense Related To Soft Dollar Arrangement ExpenseRelatedToSoftDollarArrangement	16680000	USD
CY2017	seic	Expense Related To Soft Dollar Arrangement ExpenseRelatedToSoftDollarArrangement	14623000	USD
CY2016	seic	Expense Related To Soft Dollar Arrangement ExpenseRelatedToSoftDollarArrangement	18409000	USD
CY2018	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.
CY2018	us-gaap	Impairment Of Investments ImpairmentOfInvestments	0	USD
CY2018	us-gaap	Capitalized Computer Software Additions CapitalizedComputerSoftwareAdditions	44221000	USD
CY2017	us-gaap	Capitalized Computer Software Additions CapitalizedComputerSoftwareAdditions	61043000	USD
CY2016	us-gaap	Capitalized Computer Software Additions CapitalizedComputerSoftwareAdditions	50392000	USD
CY2018	us-gaap	Capitalized Computer Software Impairments1 CapitalizedComputerSoftwareImpairments1	0	USD
CY2018	us-gaap	Goodwill And Intangible Asset Impairment GoodwillAndIntangibleAssetImpairment	0	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	505868000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	404389000	USD
CY2016	us-gaap	Net Income Loss NetIncomeLoss	333817000	USD
CY2018	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	156579000	shares
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
CY2018	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	4653000	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
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	161232000	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
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.23
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.56
CY2016	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.07
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.14
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.49
CY2016	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.03
CY2018	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	6224000	shares
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
CY2018	us-gaap	Antidilutive Securities Excluded From Computation Of Net Income Per Outstanding Unit Amount AntidilutiveSecuritiesExcludedFromComputationOfNetIncomePerOutstandingUnitAmount	53.60
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
CY2018	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	ReclassificationsCertain prior year amounts have been reclassified to conform to current year presentation.
CY2018Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	76362000	USD
CY2017Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	76760000	USD
CY2018Q4	us-gaap	Unbilled Contracts Receivable UnbilledContractsReceivable	226001000	USD
CY2017Q4	us-gaap	Unbilled Contracts Receivable UnbilledContractsReceivable	194331000	USD
CY2018Q4	us-gaap	Other Receivables Gross Current OtherReceivablesGrossCurrent	13691000	USD
CY2017Q4	us-gaap	Other Receivables Gross Current OtherReceivablesGrossCurrent	12310000	USD
CY2018Q4	seic	Receivables Gross Current ReceivablesGrossCurrent	316054000	USD
CY2017Q4	seic	Receivables Gross Current ReceivablesGrossCurrent	283401000	USD
CY2018Q4	seic	Allowancefor Doubtful Receivables AllowanceforDoubtfulReceivables	718000	USD
CY2017Q4	seic	Allowancefor Doubtful Receivables AllowanceforDoubtfulReceivables	695000	USD
CY2018Q4	us-gaap	Receivables Net Current ReceivablesNetCurrent	315336000	USD
CY2017Q4	us-gaap	Receivables Net Current ReceivablesNetCurrent	282706000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	484069000	USD
CY2017Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	456383000	USD
CY2018Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	338206000	USD
CY2017Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	309955000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	145863000	USD
CY2017Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	146428000	USD
CY2018	us-gaap	Depreciation Nonproduction DepreciationNonproduction	28792000	USD
CY2017	us-gaap	Depreciation Nonproduction DepreciationNonproduction	27311000	USD
CY2016	us-gaap	Depreciation Nonproduction DepreciationNonproduction	26440000	USD
CY2018	us-gaap	Other Amortization Of Deferred Charges OtherAmortizationOfDeferredCharges	231000	USD
CY2017	us-gaap	Other Amortization Of Deferred Charges OtherAmortizationOfDeferredCharges	218000	USD
CY2016	us-gaap	Other Amortization Of Deferred Charges OtherAmortizationOfDeferredCharges	345000	USD
CY2018Q4	us-gaap	Accrued Salaries Current AccruedSalariesCurrent	97603000	USD
CY2017Q4	us-gaap	Accrued Salaries Current AccruedSalariesCurrent	88960000	USD
CY2018Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	31000000	USD
CY2017Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	29658000	USD
CY2018Q4	seic	Accrued Sub Advisory Distribution And Other Asset Management Fees Current AccruedSubAdvisoryDistributionAndOtherAssetManagementFeesCurrent	42583000	USD
CY2017Q4	seic	Accrued Sub Advisory Distribution And Other Asset Management Fees Current AccruedSubAdvisoryDistributionAndOtherAssetManagementFeesCurrent	42365000	USD
CY2018Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	50761000	USD
CY2017Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	47179000	USD
CY2018Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	57687000	USD
CY2017Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	56896000	USD
CY2018Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	279634000	USD
CY2017Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	265058000	USD
CY2018Q4	us-gaap	Available For Sale Securities Equity Securities AvailableForSaleSecuritiesEquitySecurities	10218000	USD
CY2018Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	101683000	USD
CY2018Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	30892000	USD
CY2018Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	4887000	USD
CY2018Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	147680000	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	Equity Securities Fv Ni EquitySecuritiesFvNi	6034000	USD
CY2017Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	115543000	USD
CY2018Q4	us-gaap	Available For Sale Securities Amortized Cost AvailableForSaleSecuritiesAmortizedCost	114398000	USD
CY2018Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	126000	USD
CY2018Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	2623000	USD
CY2018Q4	us-gaap	Available For Sale Securities AvailableForSaleSecurities	111901000	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
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-1413000	USD
CY2018Q4	seic	Accumulated Other Comprehensive Income Loss Debt Securities Available For Sale Securities Adjustment Tax AccumulatedOtherComprehensiveIncomeLossDebtSecuritiesAvailableForSaleSecuritiesAdjustmentTax	-422000	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-779000	USD
CY2017Q4	seic	Accumulated Other Comprehensive Income Loss Debt Securities Available For Sale Securities Adjustment Tax AccumulatedOtherComprehensiveIncomeLossDebtSecuritiesAvailableForSaleSecuritiesAdjustmentTax	-233000	USD
CY2018	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	1065000	USD
CY2018	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	1686000	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
CY2018Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	30892000	USD
CY2017Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	21526000	USD
CY2018Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	13813000	USD
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
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	13.04
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
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.2527
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
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0135
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
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0275
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
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	23805000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	36366000	USD
CY2016	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	16017000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	5078000	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
CY2018	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	18727000	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
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Accelerated Compensation Cost ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost	1909000	USD
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Accelerated Compensation Cost ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost	11206000	USD
CY2018Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Number Of Shares SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares	6454000	shares
CY2018Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	68470000	USD
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
CY2017	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	32619000	USD
CY2016	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	28016000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	59842000	USD
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
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	2468000	shares
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	49.94
CY2018	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	3232000	shares
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	25.93
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	135000	shares
CY2018	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	49.58
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	15813000	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	41.84
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	9359000	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	32.89
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	21775000	shares
CY2017Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	10624000	shares
CY2016Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	6692000	shares
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	139087000	USD
CY2017	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	83628000	USD
CY2018Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	138706000	USD
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	143939000	USD
CY2018Q4	us-gaap	Share Price SharePrice	46.20
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	15813000	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	9359000	shares
CY2018Q4	us-gaap	Loss Contingency Pending Claims Number LossContingencyPendingClaimsNumber	7	Lawsuit
CY2018Q4	seic	Rights Agreement Conversion Rateof Rights Per Common Share RightsAgreementConversionRateofRightsPerCommonShare	1
CY2018Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.05
CY2018Q4	seic	Rights Agreement Securities Purchase Price Per Unit RightsAgreementSecuritiesPurchasePricePerUnit	150.00
CY2018Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.30
CY2018Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.33
CY2018	us-gaap	Dividends Common Stock DividendsCommonStock	97900000	USD
CY2017	us-gaap	Dividends Common Stock DividendsCommonStock	91444000	USD
CY2016	us-gaap	Dividends Common Stock DividendsCommonStock	86657000	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
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
CY2018	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-13153000	USD
CY2018	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-61000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-13092000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	12362000	USD
CY2017	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	10929000	USD
CY2016	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	9665000	USD
CY2018	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	34679000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	7855000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	7616000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	25573000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	10322000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	8476000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	82493000	USD
CY2017	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	154776000	USD
CY2016	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	158411000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	13709000	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
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	8405000	USD
CY2017	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	8002000	USD
CY2016	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	5137000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	104607000	USD
CY2017	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	174423000	USD
CY2016	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	174048000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	2550000	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
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1166000	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
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	15000	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
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	3731000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-21773000	USD
CY2016	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	620000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	108338000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	152650000	USD
CY2016	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	174668000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	579622000	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
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	34584000	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
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	614206000	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
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
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CY2016	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.019
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
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.001
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
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.038
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
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	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
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CY2017	seic	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Transition Tax On Accumulated Foreign Earnings Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent	0.026
CY2016	seic	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Transition Tax On Accumulated Foreign Earnings Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.008
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
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0
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
CY2018	seic	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Foreign Derived Intangible Income Deduction Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017ForeignDerivedIntangibleIncomeDeductionPercent	-0.002
CY2017	seic	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Foreign Derived Intangible Income Deduction Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017ForeignDerivedIntangibleIncomeDeductionPercent	0
CY2016	seic	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Foreign Derived Intangible Income Deduction Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017ForeignDerivedIntangibleIncomeDeductionPercent	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.003
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
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.176
CY2017	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.274
CY2016	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.343
CY2018	seic	Tax Cuts And Jobs Act Of2017 Foreign Derived Intangible Income Deduction Benefit TaxCutsAndJobsActOf2017ForeignDerivedIntangibleIncomeDeductionBenefit	1206000	USD
CY2017	seic	Tax Cuts And Jobs Act Of2017 Change In Tax Rate Deferred Tax Liabilities Provisional Income Tax Expense Benefit TaxCutsAndJobsActOf2017ChangeInTaxRateDeferredTaxLiabilitiesProvisionalIncomeTaxExpenseBenefit	-27153000	USD
CY2017	seic	Tax Cuts And Jobs Act Of2017 Transition Tax For Accumulated Foreign Earnings Income Tax Expense Benefit TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpenseBenefit	14743000	USD
CY2017Q4	seic	Tax Cuts And Jobs Act Of2017 Change In Tax Rate Income Tax Expense Benefit TaxCutsAndJobsActOf2017ChangeInTaxRateIncomeTaxExpenseBenefit	-12410000	USD
CY2017Q4	seic	Tax Cuts And Jobs Act Provisional Income Tax Expense Benefit Effect Of Change On Earnings Per Share Diluted TaxCutsAndJobsActProvisionalIncomeTaxExpenseBenefitEffectOfChangeOnEarningsPerShareDiluted	0.08
CY2018Q4	seic	Tax Cuts And Jobs Act Of2017 Transition Tax For Accumulated Foreign Earnings Provisional Liability TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsProvisionalLiability	10711000	USD
CY2018	seic	Tax Cuts And Jobs Act Of2017 Transition Tax For Accumulated Foreign Earnings Payment TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsPayment	1000000	USD
CY2018	seic	Effective Income Tax Reconciliation Previous Overpayment Of Taxes Benefit EffectiveIncomeTaxReconciliationPreviousOverpaymentOfTaxesBenefit	8908000	USD
CY2018Q4	seic	Tax Cuts And Jobs Actof2017 Transition Tax For Accumulated Foreign Earnings Liability Noncurrent TaxCutsAndJobsActof2017TransitionTaxForAccumulatedForeignEarningsLiabilityNoncurrent	803000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	24125000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	24725000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	74358000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	71236000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Equity Method Investments DeferredTaxAssetsEquityMethodInvestments	4118000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Equity Method Investments DeferredTaxAssetsEquityMethodInvestments	4191000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Contingencies DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsContingencies	1882000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Contingencies DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsContingencies	1918000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	1657000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	2631000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1049000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	273000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	107189000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	104974000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	72316000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	68469000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	34873000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	36505000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Capitalized Software DeferredTaxLiabilitiesDeferredExpenseCapitalizedSoftware	71067000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Capitalized Software DeferredTaxLiabilitiesDeferredExpenseCapitalizedSoftware	70575000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	6545000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	3182000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	4429000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	3549000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Goodwill DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill	1823000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Goodwill DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill	1001000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	312000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	3199000	USD
CY2018Q4	seic	Deferred Tax Liabilities Deferred Expense Capitalized Contract Cost DeferredTaxLiabilitiesDeferredExpenseCapitalizedContractCost	5490000	USD
CY2017Q4	seic	Deferred Tax Liabilities Deferred Expense Capitalized Contract Cost DeferredTaxLiabilitiesDeferredExpenseCapitalizedContractCost	0	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	960000	USD
CY2017Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	704000	USD
CY2018Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	90626000	USD
CY2017Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	82210000	USD
CY2018Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	55753000	USD
CY2017Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	45705000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	14367000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	13774000	USD
CY2018	seic	Unrecognized Tax Benefits Reductions Resulting From Lapseof Applicable Statuteof Limitations1 UnrecognizedTaxBenefitsReductionsResultingFromLapseofApplicableStatuteofLimitations1	2621000	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
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	2446000	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
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	340000	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
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	278000	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
CY2018	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	2621000	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
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	14367000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	14480000	USD
CY2016Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	17287000	USD
CY2018	us-gaap	Income Tax Examination Penalties And Interest Expense IncomeTaxExaminationPenaltiesAndInterestExpense	1289000	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
CY2018	us-gaap	Revenues Revenues	1624167000	USD
CY2018	us-gaap	Operating Costs And Expenses OperatingCostsAndExpenses	1116533000	USD
CY2018	us-gaap	Gross Profit GrossProfit	507634000	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
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	441988000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	396944000	USD
CY2016	us-gaap	Operating Income Loss OperatingIncomeLoss	375694000	USD
CY2018	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	73316000	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
CY2018	us-gaap	Depreciation Depreciation	28792000	USD
CY2017	us-gaap	Depreciation Depreciation	27311000	USD
CY2016	us-gaap	Depreciation Depreciation	26440000	USD
CY2018	us-gaap	Adjustment For Amortization AdjustmentForAmortization	48895000	USD
CY2017	us-gaap	Adjustment For Amortization AdjustmentForAmortization	48275000	USD
CY2016	us-gaap	Adjustment For Amortization AdjustmentForAmortization	45392000	USD
CY2018Q4	us-gaap	Assets Assets	1971668000	USD
CY2017Q4	us-gaap	Assets Assets	1853369000	USD
CY2018	us-gaap	Revenues Revenues	1624167000	USD
CY2017	us-gaap	Revenues Revenues	1526552000	USD
CY2016	us-gaap	Revenues Revenues	1401545000	USD
CY2018Q4	us-gaap	Assets Assets	1971668000	USD
CY2017Q4	us-gaap	Assets Assets	1853369000	USD
CY2016Q4	us-gaap	Goodwill Goodwill	0	USD
CY2017	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	52990000	USD
CY2017Q4	us-gaap	Goodwill Goodwill	52990000	USD
CY2018	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	11499000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	64489000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	5090000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	36760000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	30130000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	1552000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	31670000	USD
CY2017Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	28578000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	3538000	USD
CY2017	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1552000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	3683000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	3683000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	3683000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	3336000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	2989000	USD
CY2018	us-gaap	Revenues Revenues	1624167000	USD
CY2018	us-gaap	Revenues Revenues	1624167000	USD
CY2018Q4	us-gaap	Capitalized Contract Cost Net CapitalizedContractCostNet	24007000	USD
CY2018	seic	Capitalized Contract Cost Amount Capitalized During Period CapitalizedContractCostAmountCapitalizedDuringPeriod	8122000	USD
CY2018	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	2756000	USD
CY2018	us-gaap	Capitalized Contract Cost Impairment Loss CapitalizedContractCostImpairmentLoss	0	USD
CY2018Q1	us-gaap	Revenues Revenues	405598000	USD
CY2018Q2	us-gaap	Revenues Revenues	404830000	USD
CY2018Q3	us-gaap	Revenues Revenues	408682000	USD
CY2018Q4	us-gaap	Revenues Revenues	405057000	USD
CY2018Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	158758000	USD
CY2018Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	154254000	USD
CY2018Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	157595000	USD
CY2018Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	143599000	USD
CY2018Q1	us-gaap	Profit Loss ProfitLoss	139838000	USD
CY2018Q2	us-gaap	Profit Loss ProfitLoss	121677000	USD
CY2018Q3	us-gaap	Profit Loss ProfitLoss	128319000	USD
CY2018Q4	us-gaap	Profit Loss ProfitLoss	116034000	USD
CY2018Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.89
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.77
CY2018Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.82
CY2018Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.75
CY2018Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.86
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.75
CY2018Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.80
CY2018Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.73
CY2018Q1	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.119
CY2018Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.211
CY2018Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.186
CY2018Q4	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.192
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	Tax Cuts And Jobs Act Of2017 Change In Tax Rate Income Tax Expense Benefit TaxCutsAndJobsActOf2017ChangeInTaxRateIncomeTaxExpenseBenefit	-12410000	USD
CY2017Q4	seic	Tax Cuts And Jobs Act Provisional Income Tax Expense Benefit Effect Of Change On Earnings Per Share Diluted TaxCutsAndJobsActProvisionalIncomeTaxExpenseBenefitEffectOfChangeOnEarningsPerShareDiluted	0.08

Files In Submission

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0000350894-19-000012.txt	Edgar Link	pending
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$SEIC
SEI INVESTMENTS CO Stock $seic

2019 Q1 Form 10-K Financial Statement

#000035089419000012 Filed on February 25, 2019

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SEIC SEI INVESTMENTS CO Stock $seic

2019 Q1 Form 10-K Financial Statement

#000035089419000012 Filed on February 25, 2019

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SEIC
SEI INVESTMENTS CO Stock $seic