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, 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
Balance at Dec. 31, 2013		1,479,626	676	408,083	(65,777)	[1]	1,133,873	(10,590)	13,361
Net income including noncontrolling interests		129,619					126,198		3,421
Other comprehensive income		1,099			1,099	[1]
Common stock issued under share-based compensation plans	[2]	9,805	6	9,511				288
Common stock issued under employee stock purchase plan		2,677		2,677
Common stock dividends		(16,109)		200			(16,309)
Repurchase of common stock		(84,565)	(20)	(84,545)
Distributions to noncontrolling interests		(2,750)							(2,750)
Share-based compensation expense		6,321		6,321
Balance at Sep. 30, 2014		$ 1,525,723	$ 662	$ 342,247	$ (64,678)	[1]	$ 1,243,762	$ (10,302)	$ 14,032

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

[2] Includes the tax benefit associated with share-based compensation of $6.2 million and $1.3 million for the nine months ended September 30, 2014 and 2013, respectively.