Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 222,959	$ 151,060
Adjustments to reconcile net income to net cash provided by operating activities (See Note 1)	17,336	(5,161)
Net cash provided by operating activities	240,295	145,899
Cash flows from investing activities:
Additions to property and equipment	(10,413)	(21,651)
Additions to capitalized software	(31,044)	(25,894)
Purchases of marketable securities	(48,653)	(22,505)
Prepayments and maturities of marketable securities	29,462	36,938
Sales of marketable securities	7,284	910
Purchases of other investments	(2,604)	(2,568)
Sale of subsidiary, net of cash transferred (See Note 13)	6,028	0
Net cash used in investing activities	(49,940)	(34,770)
Cash flows from financing activities:
Purchase and retirement of common stock	(144,121)	(111,593)
Proceeds from issuance of common stock	54,788	30,624
Tax benefit on stock options exercised	8,345	(834)
Payment of dividends	(34,400)	(52,635)
Net cash used in financing activities	(115,388)	(134,438)
Net increase (decrease) in cash and cash equivalents	74,967	(23,309)
Cash and cash equivalents, beginning of period	452,247	420,986
Cash and cash equivalents, end of period	$ 527,214	$ 397,677