Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income	$ 250,276	$ 241,616
Adjustments to reconcile net income to net cash provided by operating activities (See Note 1)	24,207	2,702
Net cash provided by operating activities	274,483	244,318
Cash flows from investing activities:
Additions to restricted cash	(518)	0
Additions to property and equipment	(35,719)	(26,422)
Additions to capitalized software	(22,508)	(26,193)
Purchases of marketable securities	(34,040)	(42,305)
Prepayments and maturities of marketable securities	27,008	27,224
Sales of marketable securities	7,103	18,133
Receipt of contingent payment from sale of SEI AK	2,791	5,582
Purchases of other investments	(1,000)	(2,000)
Net cash used in investing activities	(56,883)	(45,981)
Cash flows from financing activities:
Purchase and retirement of common stock	(213,256)	(215,777)
Proceeds from issuance of common stock	52,349	81,426
Tax benefit on stock options exercised	11,446	13,372
Payment of dividends	(80,030)	(74,294)
Net cash used in financing activities	(229,491)	(195,273)
Effect of exchange rate changes on cash and cash equivalents	(7,966)	(3,423)
Net decrease in cash and cash equivalents	(19,857)	(359)
Cash and cash equivalents, beginning of period	667,446	578,273
Cash and cash equivalents, end of period	$ 647,589	$ 577,914