CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOW (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flow from operating activities:
Net income	$ 153,613	$ 127,248
Adjustments for cash from operating activities:
Depreciation and amortization	32,592	28,999
Stock-based compensation expense	8,283	7,491
Excess tax benefits from stock-based compensation payment arrangements	(8,720)	(5,429)
Net change in components of working capital	(12,135)	9,851
Net change in other long-term assets and liabilities	6,621	(3,956)
Cash flow provided by operating activities	180,254	164,204
Cash flow from investing activities:
Additions to property, plant and equipment	(29,685)	(31,523)
Proceeds from disposals of fixed assets	802	1,015
Purchases of short-term investments	(110,744)	(34,466)
Sales and maturities of short-term investments	75,488	46,065
Acquisitions, net of cash acquired	201
Cash flow used in investing activities	(63,938)	(18,909)
Cash flow from financing activities:
Issuance of senior notes		498,730
Borrowings under credit facilities	101,300	227,900
Repayments under credit facilities	(119,215)	(708,747)
Payments of fees and expenses related to debt financing		(4,315)
Proceeds from exercise of stock options	30,682	22,418
Excess tax benefits from stock-based compensation payment arrangements	8,720	5,429
Payments to shareholders of noncontrolling interests	(1,247)
Purchase and retirement of treasury stock	(85,300)	(81,885)
Dividend payments		(2,448)
Cash flow used in financing activities	(65,060)	(42,918)
Effect of exchange rate changes on cash and cash equivalents	(7,113)	3,520
Net change in cash and cash equivalents	44,143	105,897
Cash and cash equivalents balance, beginning of period	690,850	515,086
Cash and cash equivalents balance, end of period	734,993	620,983
Cash paid for:
Interest	12,740	2,640
Income taxes	$ 38,852	$ 45,063