Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Operating Activities:
Net earnings	$ 92,663	$ 84,021	$ 173,273	$ 160,743
Adjustments to reconcile net earnings to net cash from operating activities:
Provision for losses (recoveries) on accounts receivable	100	(388)	1,041	(855)
Deferred income tax expense (benefit)	5,818	(5,739)	12,940	(258)
Excess tax benefits from stock plans	(584)	(806)	(1,683)	(4,232)
Stock compensation expense	11,040	10,926	22,045	21,526
Depreciation and amortization	11,674	9,670	22,952	19,215
Other	241	206	449	423
Changes in operating assets and liabilities:
Increase in accounts receivable	(48,223)	(63,260)	(9,367)	(50,292)
(Increase) decrease in other current assets	(91)	1,642	(576)	3,566
Increase in accounts payable and accrued expenses	45,080	70,674	43,690	84,233
(Decrease) increase in income taxes payable, net	(33,692)	(14,132)	(15,474)	6,142
Net cash from operating activities	84,026	92,814	249,290	240,211
Investing Activities:
(Increase) decrease in short-term investments, net	(89,803)	15,878	(89,765)	98
Purchase of property and equipment	(17,141)	(9,814)	(27,209)	(26,902)
Other, net	1,264	(91)	820	379
Net cash from investing activities	(105,680)	5,973	(116,154)	(26,425)
Financing Activities:
Proceeds from issuance of common stock	7,548	7,482	18,477	20,402
Repurchases of common stock	(21,600)	(84,401)	(39,281)	(106,266)
Excess tax benefits from stock plans	584	806	1,683	4,232
Dividends paid	(61,899)	(59,358)	(61,899)	(59,358)
Purchase of noncontrolling interest	0	0	(7,730)	0
Net cash from financing activities	(75,367)	(135,471)	(88,750)	(140,990)
Effect of exchange rate changes on cash and cash equivalents	(11,557)	(11,984)	(19,119)	(2,905)
(Decrease) increase in cash and cash equivalents	(108,578)	(48,668)	25,267	69,891
Cash and cash equivalents at beginning of period	1,394,687	1,412,915	1,260,842	1,294,356
Cash and cash equivalents at end of period	1,286,109	1,364,247	1,286,109	1,364,247
Taxes Paid:
Income taxes	$ 85,195	$ 77,583	$ 112,146	$ 104,095