Unaudited Condensed Consolidated Statement of Stockholders' Equity (USD $) In Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Non-Controlling Interest
Beginning Balance at Dec. 31, 2011	$ 1,293,576	$ 75	$ 802,194	$ 420,421	$ (483)	$ (33,154)	$ 104,523
Beginning Balance (in shares) at Dec. 31, 2011		75,393
Shares issued on exercise of stock options and warrants (in shares)		252
Shares issued on exercise of stock options and warrants	694	1	693
Tax benefit of stock option exercises	769		769
Compensation expense in connection with restricted stock and stock options	2,598		2,598
Cost of shares repurchased on vesting of restricted stock and exercise of stock options	(651)					(651)
Cost of shares repurchased on the open market	(35,662)					(35,662)
Comprehensive income	31,362			27,599	483		3,280
Distributions to joint venture partners	(2,277)						(2,277)
Non-controlling interest of acquired companies	1,099						1,099
Ending Balance at Mar. 31, 2012	$ 1,291,508	$ 76	$ 806,254	$ 448,020		$ (69,467)	$ 106,625
Ending Balance (in shares) at Mar. 31, 2012		75,645