Condensed Consolidated Statements Of Equity (USD $) In Thousands		Total	Common Stock [Member]	Capital Surplus [Member]	Accumulated Other Comprehensive (Loss) Income [Member]		Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2011		$ 1,245,131	$ 681	$ 417,136	$ (78,649)	[1]	$ 910,042	$ (14,476)	$ 10,397
Net income including noncontrolling interests		102,098					100,174		1,924
Other comprehensive income		1,719			1,719	[1]
Common stock issued under share-based compensation plans	[2]	8,198	6	6,363				1,829
Common stock issued under employee stock purchase plan		1,913		1,913
Common stock dividends		(9,988)		90			(10,078)
Repurchase of common stock		(23,912)	(9)	(23,903)
Distributions to noncontrolling interests		(1,600)							(1,600)
Share-based compensation expense		5,285		5,285
Balance at Sep. 30, 2012		1,328,844	678	406,884	(76,930)	[1]	1,000,138	(12,647)	10,721
Balance at Dec. 31, 2012		1,357,179	680	416,104	(81,040)	[1]	1,022,239	(11,903)	11,099
Net income including noncontrolling interests		81,085					77,871		3,214
Other comprehensive income		1,251			1,251	[1]
Common stock issued under share-based compensation plans	[2]	2,660	2	2,451				207
Common stock issued under employee stock purchase plan		2,088		2,088
Common stock dividends		(8,052)		40			(8,092)
Repurchase of common stock		(4,998)	(1)	(4,997)
Distributions to noncontrolling interests		(1,300)							(1,300)
Share-based compensation expense		5,288		5,288
Balance at Sep. 30, 2013		$ 1,435,201	$ 681	$ 420,974	$ (79,789)	[1]	$ 1,092,018	$ (11,696)	$ 13,013

[1] Represents cumulative foreign currency translation adjustments and post retirement liability adjustments.

[2] Includes the tax benefit associated with share-based compensation of $1.3 million and $6.9 million for the nine months ended September 30, 2013 and 2012, respectively.