Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income [Member]	Noncontrolling Interest [Member]
Stockholders' Equity, Beginning Balance at Dec. 31, 2011	$ 577,826	$ 484	$ 335,337	$ 144,424	$ 7,173	$ 90,408
Shares, Outstanding, Beginning Balance at Dec. 31, 2011		48,432,860
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	187,593			161,835		25,758
Other comprehensive income	4,389				3,799	590
Performance Units Vested		11,101
Restricted stock grant		13,500
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		1
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Units, Requisite Service Period Recognition			(1)
Minimum Tax Withholding Settlement	(205)		(205)
Restricted stock compensation	240		240
Noncontrolling Interest Distribution	(15,048)					(15,048)
Dividends, Common Stock				(50,871)
Cash Dividends declared ($1.05 per share)	(50,871)
Stockholders' Equity, Ending Balance at Sep. 30, 2012	$ 703,924	$ 485	$ 335,371	$ 255,388	$ 10,972	$ 101,708
Shares, Outstanding, Ending Balance at Sep. 30, 2012		48,457,461