Condensed, Consolidated Statements of Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Noncontrolling Interests
Beginning Balances, shares at Dec. 31, 2013		88,508
Beginning Balances at Dec. 31, 2013	$ 1,317,616	$ 89	$ 384,797	$ 928,720	$ (6,190)	$ 10,200
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (excludes $1,392 and $1,088 related to redeemable and mandatorily redeemable noncontrolling interests as of September 30, 2015 and $723 and $1,172 as of September 30, 2014)	108,879			107,079		1,800
Other comprehensive loss (excludes $338 and $358 as of September 30, 2015 and 2014, respectively, related to mandatorily redeemable noncontrolling interests)	(6,561)				(6,391)	(170)
Formation of noncontrolling interests	933					933
Distribution to noncontrolling interests	(1,627)					(1,627)
Purchase of noncontrolling interests	29		29
Share-based compensation	12,234		12,234
Issuance of common stock under stock incentive plans, shares		614
Issuance of common stock under stock incentive plans	926		926
Stock repurchases, shares		(3,830)
Stock repurchases	(139,910)	$ (4)	(139,906)
Excess tax benefit from stock based compensation	3,808		3,808
Ending Balances, shares at Sep. 30, 2014		85,292
Ending Balances at Sep. 30, 2014	$ 1,296,327	$ 85	261,888	1,035,799	(12,581)	11,136
Beginning Balances, shares at Dec. 31, 2014	82,937	82,937
Beginning Balances at Dec. 31, 2014	$ 1,211,621	$ 83	155,802	1,064,158	(19,397)	10,975
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (excludes $1,392 and $1,088 related to redeemable and mandatorily redeemable noncontrolling interests as of September 30, 2015 and $723 and $1,172 as of September 30, 2014)	149,464			147,454		2,010
Other comprehensive loss (excludes $338 and $358 as of September 30, 2015 and 2014, respectively, related to mandatorily redeemable noncontrolling interests)	(24,936)				(24,512)	(424)
Formation of noncontrolling interests	2,661					2,661
Distribution to noncontrolling interests	(1,784)					(1,784)
Purchase of noncontrolling interests	(690)		(217)			(473)
Share-based compensation	12,086		12,086
Issuance of common stock under stock incentive plans, shares		633
Issuance of common stock under stock incentive plans	1,571	$ 1	1,570
Stock repurchases, shares		(3,003)
Stock repurchases	(161,117)	$ (3)	(161,114)
Excess tax benefit from stock based compensation	$ 8,008		8,008
Ending Balances, shares at Sep. 30, 2015	80,567	80,567
Ending Balances at Sep. 30, 2015	$ 1,196,884	$ 81	$ 16,135	$ 1,211,612	$ (43,909)	$ 12,965