Condensed, Consolidated Statements of Equity (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Noncontrolling Interests
Beginning Balances at Dec. 31, 2013	$ 1,317,616	$ 89	$ 384,797	$ 928,720	$ (6,190)	$ 10,200
Beginning Balances, shares at Dec. 31, 2013		88,508
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (excludes $417 and $359 related to redeemable and mandatorily redeemable noncontrolling interests as of March 31, 2015 and $151 and $368 as of March 31, 2014)	34,396			34,043		353
Other comprehensive loss (excludes $195 and $318 as of March 31, 2015 and 2014, respectively, related to mandatorily redeemable noncontrolling interests)	(5,203)				(5,093)	(110)
Formation of noncontrolling interests	81					81
Distribution to noncontrolling interests	(502)					(502)
Purchase of noncontrolling interests	30		30
Share-based compensation	4,544		4,544
Issuance of common stock under stock incentive plans, shares		87
Issuance of common stock under stock incentive plans	372		372
Stock repurchases, shares		(307)
Stock repurchases, value	(9,793)	(1)	(9,792)
Excess tax benefit from stock based compensation	392		392
Ending Balances at Mar. 31, 2014	1,341,933	88	380,343	962,763	(11,283)	10,022
Ending Balances, shares at Mar. 31, 2014		88,288
Beginning Balances at Dec. 31, 2014	1,211,621	83	155,802	1,064,158	(19,397)	10,975
Beginning Balances, shares at Dec. 31, 2014	82,937	82,937
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (excludes $417 and $359 related to redeemable and mandatorily redeemable noncontrolling interests as of March 31, 2015 and $151 and $368 as of March 31, 2014)	38,777			38,301		476
Other comprehensive loss (excludes $195 and $318 as of March 31, 2015 and 2014, respectively, related to mandatorily redeemable noncontrolling interests)	(15,485)				(15,208)	(277)
Formation of noncontrolling interests	(14)					(14)
Distribution to noncontrolling interests	(598)					(598)
Purchase of noncontrolling interests	(690)		(217)			(473)
Share-based compensation	4,132		4,132
Issuance of common stock under stock incentive plans, shares		76
Issuance of common stock under stock incentive plans	404		404
Stock repurchases, shares		(878)
Stock repurchases, value	(44,845)	(1)	(44,844)
Excess tax benefit from stock based compensation	791		791
Ending Balances at Mar. 31, 2015	$ 1,194,093	$ 82	$ 116,068	$ 1,102,459	$ (34,605)	$ 10,089
Ending Balances, shares at Mar. 31, 2015	82,135	82,135