Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Activities:
Net earnings	$ 386,243	$ 344,205	$ 240,397
Adjustments to reconcile net earnings to net cash provided by operating activities:
Provision for losses on accounts receivable	1,327	3,414	804
Deferred income tax (benefit) expense	(4,065)	10,569	(1,609)
Excess tax benefits from stock plans	(5,300)	(23,863)	(5,726)
Stock compensation expense	44,278	43,743	39,135
Depreciation and amortization	36,776	36,900	40,035
Loss (gain) on sale of assets	360	(321)	(42)
Amortization of other intangible assets	1,156	1,413	1,520
Changes in operating assets and liabilities:
Decrease (increase) in accounts receivable	46,915	(188,823)	(1,077)
(Decrease) increase in accounts payable and accrued expenses	(40,819)	130,138	29,910
(Decrease) increase in income taxes payable, net	(3,237)	39,495	(12,706)
(Increase) decrease in other current assets	(6,503)	(1,352)	159
Net cash provided by operating activities	457,131	395,518	330,800
Investing Activities:
Decrease in short-term investments, net	29	188	26
Purchase of property and equipment	(78,115)	(42,408)	(34,700)
Proceeds from sale of property and equipment	193	360	276
Prepayment on long-term leases, net	(936)	0	(5,049)
Other	(1,510)	(319)	(1,901)
Net cash used in investing activities	(80,339)	(42,179)	(41,348)
Financing Activities:
Proceeds from issuance of common stock	56,646	99,784	46,925
Repurchases of common stock	(112,071)	(246,312)	(84,509)
Excess tax benefits from stock plans	5,300	23,863	5,726
Dividends paid	(106,011)	(84,872)	(80,555)
Distributions to noncontrolling interest	(955)	(1,051)	(1,084)
Purchase of noncontrolling interest	0	0	(3,851)
Net cash used in financing activities	(157,091)	(208,588)	(117,348)
Effect of exchange rate changes on cash and cash equivalents	(9,810)	13,785	12,797
Increase in cash and cash equivalents	209,891	158,536	184,901
Cash and cash equivalents at beginning of year	1,084,465	925,929	741,028
Cash and cash equivalents at end of year	1,294,356	1,084,465	925,929
Interest and Taxes Paid:
Interest	296	110	497
Income taxes	$ 266,621	$ 171,618	$ 158,745