Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income	$ 1,076,410	$ 904,246
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	145,191	132,013
Provision for doubtful accounts	2,878	5,985
Deferred income taxes	(43,373)	(22,844)
Stock-based compensation expense	100,622	86,353
Excess tax benefits on stock-based compensation plans	(14,547)	(16,450)
Other	12,796	52,171
Changes in assets and liabilities:
Trade accounts receivable	(167,655)	(273,502)
Other current assets	(75,821)	(56,647)
Other noncurrent assets	22,880	(9,604)
Accounts payable	44,601	3,251
Other current and noncurrent liabilities	44,832	112,931
Net cash provided by operating activities	1,148,814	917,903
Cash flows from investing activities:
Purchases of property and equipment	(137,547)	(154,346)
Purchases of investments	(2,180,305)	(1,368,812)
Proceeds from maturity or sale of investments	1,702,703	1,297,258
Business combinations, net of cash acquired	(11,487)	(152,476)
Net cash (used in) investing activities	(626,636)	(378,376)
Cash flows from financing activities:
Issuance of common stock under stock-based compensation plans	49,853	76,837
Excess tax benefits on stock-based compensation plans	14,547	16,450
Repurchases of common stock	(171,288)	(154,336)
Debt issuance costs	(1,500)	0
Net cash (used in) financing activities	(108,388)	(61,049)
Effect of exchange rate changes on cash and cash equivalents	(9,177)	(17,436)
Increase in cash and cash equivalents	404,613	461,042
Cash and cash equivalents, beginning of year	2,213,006	1,570,077
Cash and cash equivalents, end of period	$ 2,617,619	$ 2,031,119