CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOW (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flow from operating activities:
Net income	$ 127,248	$ 128,885
Adjustments for cash from operating activities:
Depreciation and amortization	28,999	27,357
Stock-based compensation expense	7,491	6,320
Excess tax benefits from stock-based compensation payment arrangements	(5,429)	(4,625)
Net change in components of working capital	9,851	(44,065)
Net change in other long-term assets and liabilities	(3,956)	(6,134)
Cash flow provided by operating activities	164,204	107,738
Cash flow from investing activities:
Additions to property, plant and equipment	(31,523)	(23,321)
Proceeds from disposals of fixed assets	1,015	143
Purchases of short-term investments	(34,466)	(20,423)
Sales and maturities of short-term investments	46,065	20,342
Cash flow used in investing activities	(18,909)	(23,259)
Cash flow from financing activities:
Issuance of senior notes	498,730
Borrowings under credit facilities	227,900	212,270
Repayments under credit facilities	(708,747)	(62,700)
Payments of fees and expenses related to debt financing	(4,315)
Proceeds from exercise of stock options	22,418	11,921
Excess tax benefits from stock-based compensation payment arrangements	5,429	4,625
Payments to shareholders of noncontrolling interests		(496)
Purchase and retirement of treasury stock	(81,885)	(188,503)
Dividend payments	(2,448)	(2,633)
Cash flow used in financing activities	(42,918)	(25,516)
Effect of exchange rate changes on cash and cash equivalents	3,520	8,148
Net change in cash and cash equivalents	105,897	67,111
Cash and cash equivalents balance, beginning of period	515,086	525,888
Cash and cash equivalents balance, end of period	620,983	592,999
Cash paid for:
Interest	2,640	2,517
Income taxes	$ 45,063	$ 30,454