Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 68,009	$ 40,771
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property and equipment and amortization of other intangible assets	12,741	13,968
Stock-based compensation	8,130	14,950
Excess tax benefit associated with stock-based compensation	(3,567)	(3,615)
Other, net	1,006	2,129
Changes in operating assets and liabilities
Accounts receivable	1,392	(985)
Deferred tax assets and other assets	12,720	3,975
Accounts payable and accrued liabilities	(44,872)	(16,814)
Deferred revenues	54,719	35,908
Net cash provided by operating activities	110,278	90,287
Cash flows from investing activities:
Proceeds from maturities and sales of marketable securities	5,060	11,238
Purchases of marketable securities	(5,082)	(18,008)
Purchases of property and equipment	(12,917)	(15,565)
Other investing activities	0	(1,181)
Net cash used in investing activities	(12,939)	(23,516)
Cash flows from financing activities:
Proceeds from issuance of common stock from option exercises and employee stock purchase plans	11,390	16,550
Repurchases of common stock	(75,149)	(207,428)
Excess tax benefit associated with stock-based compensation	3,567	3,615
Other financing activities	189	0
Net cash used in financing activities	(60,003)	(187,263)
Effect of exchange rate changes on cash and cash equivalents	2,355	1,690
Net increase (decrease) in cash and cash equivalents	39,691	(118,802)
Cash and cash equivalents at beginning of period	1,313,349	1,559,628
Cash and cash equivalents at end of period	1,353,040	1,440,826
Supplemental cash flow disclosures:
Cash paid for interest, net of capitalized interest	20,036	20,062
Income Taxes Paid, Net	$ 13,186	$ 2,539