Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Operating Activities:
Net earnings	$ 102,797	$ 92,729	$ 278,720	$ 266,002
Adjustments to reconcile net earnings to net cash from operating activities:
Provision for losses (recoveries) on accounts receivable	564	1,496	(55)	2,537
Deferred income tax (benefit) expense	(2,085)	(33,185)	8,000	(20,245)
Excess tax benefits from stock plans	(47)	0	(1,031)	(1,683)
Stock compensation expense	10,049	11,015	32,220	33,060
Depreciation and amortization	12,741	12,629	37,540	35,581
Other	139	187	345	636
Changes in operating assets and liabilities:
Increase in accounts receivable	(58,984)	(5,115)	(131,374)	(14,482)
Increase (decrease) in accounts payable and accrued expenses	23,113	(8,875)	114,036	34,815
Increase (decrease) in income taxes payable, net	2,050	30,114	(27,115)	14,640
Increase in other current assets	(3,646)	(4,702)	(5,852)	(5,278)
Net cash from operating activities	86,691	96,293	305,434	345,583
Investing Activities:
Purchase of short-term investments	(40,275)	(9,991)	(136,706)	(99,890)
Proceeds from maturities of short-term investments	86,107	66	122,726	200
Purchase of property and equipment	(8,255)	(15,482)	(26,650)	(42,691)
Escrow deposit for land acquisition	0	0	(27,101)	0
Other, net	370	306	504	1,126
Net cash from investing activities	37,947	(25,101)	(67,227)	(141,255)
Financing Activities:
Proceeds from issuance of common stock	28,452	33,615	58,469	52,092
Repurchases of common stock	(117,044)	(85,925)	(475,160)	(125,206)
Excess tax benefits from stock plans	47	0	1,031	1,683
Dividends paid	0	0	(62,807)	(61,899)
Purchase of noncontrolling interest	0	0	0	(7,730)
Distributions to noncontrolling interest	0	(1,161)	(85)	(1,161)
Net cash from financing activities	(88,545)	(53,471)	(478,552)	(142,221)
Effect of exchange rate changes on cash and cash equivalents	(16,174)	6,500	(16,827)	(12,619)
Increase (decrease) in cash and cash equivalents	19,919	24,221	(257,172)	49,488
Cash and cash equivalents at beginning of period	970,561	1,286,109	1,247,652	1,260,842
Cash and cash equivalents at end of period	990,480	1,310,330	990,480	1,310,330
Taxes Paid:
Income taxes	$ 61,899	$ 62,053	$ 195,358	$ 174,199