Changes in Equity and Noncontrolling Interests (Details) (USD $) In Thousands, except Share data in Millions, unless otherwise specified	3 Months Ended					3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012 Common Stock	Mar. 31, 2011 Common Stock	Dec. 31, 2010 Common Stock	Mar. 31, 2012 Additional Paid-in Capital	Mar. 31, 2011 Additional Paid-in Capital	Mar. 31, 2012 Accumulated Earnings	Mar. 31, 2011 Accumulated Earnings	Mar. 31, 2012 Accum. Other Comprehensive Loss	Mar. 31, 2011 Accum. Other Comprehensive Loss	Mar. 31, 2012 Treasury Stock	Mar. 31, 2011 Treasury Stock	Mar. 31, 2012 Noncontrolling Interests	Mar. 31, 2011 Noncontrolling Interests
Increase (Decrease) In Shareholders' Equity
Balance at beginning of period (in shares)			163	176	176
Balance at beginning of period	$ 2,184,786	$ 2,342,715	$ 163	$ 176	$ 176	$ 189,166	$ 144,855	$ 2,102,497	$ 2,260,581					$ 13,017	$ 21,860
Balance at beginning of period	(120,057)									(120,057)	(84,757)
Net income	127,248	128,885						126,563	127,958					685	927
Translation adjustments	16,164	23,495								16,148	23,453			16	42
Revaluation of forward contract derivatives	262									262
Defined benefit plan liability adjustment, net of tax		222									222
Payments to shareholders of non-controlling interests		(496)													(496)
Purchase of treasury stock	(81,885)	(188,503)										(81,885)	(188,503)
Retirement of treasury stock			(1)					(81,884)				81,885
Retirement of treasury stock (in shares)			(1)
Stock options exercised, including tax benefit	27,701	16,483	1			27,700	16,483
Stock options exercised, including tax benefit (in shares)			1
Dividends declared	(17,049)	(2,642)						(17,049)	(2,642)
Stock-based compensation expense	7,491	6,320				7,491	6,320
Balance at end of period (in shares)			163	176	176
Balance at end of period	2,264,718	2,326,479	163	176	176	224,357	167,658	2,130,127	2,385,897				(188,503)	13,718	22,333
Balance at end of period	$ (103,647)									$ (103,647)	$ (61,082)