Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Operating Activities:
Net earnings	$ 118,736	$ 102,797	$ 344,397	$ 278,720
Adjustments to reconcile net earnings to net cash from operating activities:
Provision for losses (recoveries) on accounts receivable	134	564	995	(55)
Deferred income tax (benefit) expense	(7,611)	(2,085)	13,312	8,000
Excess tax benefits from stock plans	0	(47)	(1,846)	(1,031)
Stock compensation expense	10,919	10,049	32,489	32,220
Depreciation and amortization	11,475	12,741	34,424	37,540
Other	2	139	115	345
Changes in operating assets and liabilities:
Decrease (increase) in accounts receivable	2,466	(58,984)	18,910	(131,374)
(Decrease) increase in accounts payable and accrued expenses	(19,622)	23,113	3,311	114,036
Increase (decrease) in income taxes payable, net	19,978	2,050	4,110	(27,115)
Increase in other current assets	(3,801)	(3,646)	(1,419)	(5,852)
Net cash from operating activities	132,676	86,691	448,798	305,434
Investing Activities:
Purchase of short-term investments	0	(40,275)	(47,008)	(136,706)
Proceeds from maturities of short-term investments	38,788	86,107	79,084	122,726
Purchase of property and equipment	(9,546)	(8,255)	(31,903)	(26,650)
Escrow deposit for land acquisition	0	0	0	(27,101)
Other, net	(2,666)	370	(2,482)	504
Net cash from investing activities	26,576	37,947	(2,309)	(67,227)
Financing Activities:
Proceeds from issuance of common stock	54,606	28,452	114,701	58,469
Repurchases of common stock	(209,970)	(117,044)	(415,475)	(475,160)
Excess tax benefits from stock plans	0	47	1,846	1,031
Dividends paid	0	0	(68,781)	(62,807)
Distributions to noncontrolling interest	0	0	(857)	(85)
Net cash from financing activities	(155,364)	(88,545)	(368,566)	(478,552)
Effect of exchange rate changes on cash and cash equivalents	(20,932)	(16,174)	(36,347)	(16,827)
(Decrease) increase in cash and cash equivalents	(17,044)	19,919	41,576	(257,172)
Cash and cash equivalents at beginning of period	985,727	970,561	927,107	1,247,652
Cash and cash equivalents at end of period	968,683	990,480	968,683	990,480
Taxes Paid:
Income taxes	$ 60,374	$ 61,899	$ 190,024	$ 195,358