Condensed Consolidated Statements of Changes in Equity (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Treasury Stock [Member]	Total Attributed To Stockholders [Member]	Non-controlling Interests [Member]	Redeemable Non-controlling Interests [Member]
Beginning Balance at Dec. 31, 2012	$ 244,471	$ 81	$ 942,825	$ (680,411)	$ (287)	$ (17,734)	$ 244,474	$ (3)	$ 3,163
Balance, shares at Dec. 31, 2012		7,826,674				245,000
Net income (loss)	50,388			50,434			50,434	(46)	(118)
Net unrealized gain on securities available-for-sale	91				91		91
Foreign currency translation adjustment	19				19		19
Activity of noncontrolling interests, net									15,810
Issuance of common stock, net	191,581	13	191,568				191,581
Issuance of common stock, net, shares		1,298,386
Repurchase of common shares	(19,704)					(19,704)	(19,704)
Repurchase of common shares, shares	105,000	(105,000)				105,000
Issuance of common stock related to employee stock transactions	983	1	982				983
Issuance of common stock related to employee stock transactions, shares		80,738
Taxes paid on stock-based compensation	(7,493)		(7,493)				(7,493)
Stock-based compensation	5,468		5,468				5,468
Ending Balance at Sep. 30, 2013	465,804	95	1,133,350	(629,977)	(177)	(37,438)	465,853	(49)	18,855
Balance, shares at Sep. 30, 2013		9,100,798				350,000
Beginning Balance at Dec. 31, 2013	492,868	95	1,135,644	(605,221)	(150)	(37,438)	492,930	(62)	42,186
Balance, shares at Dec. 31, 2013	9,105,521	9,105,521				350,000
Net income (loss)	78,737	0	0	78,821	0	0	78,821	(84)	(183)
Net unrealized gain on securities available-for-sale	90	0	0	0	90	0	90	0	0
Foreign currency translation adjustment	(80)	0	0	0	(80)	0	(80)	0	0
Activity of noncontrolling interests, net	0	0	0	0	0	0	0	0	(19,738)
Cash dividends declared	(8,333)	0	(8,333)	0	0	0	(8,333)		0
Repurchase of common shares	(26,257)	0	0	0	0	(26,257)	(26,257)	0	0
Repurchase of common shares, shares	136,874	(136,874)				136,874
Issuance of common stock related to employee stock transactions	1,224	0	1,224	0	0	0	1,224	0	0
Issuance of common stock related to employee stock transactions, shares		90,731				0
Taxes paid on stock-based compensation	(9,512)	0	(9,512)	0	0	0	(9,512)	0	0
Stock-based compensation	6,604	0	6,604	0	0	0	6,604	0	0
Excess tax benefits from stock-based compensation	25,089	0	25,089	0	0	0	25,089	0	0
Ending Balance at Sep. 30, 2014	$ 560,430	$ 95	$ 1,150,716	$ (526,400)	$ (140)	$ (63,695)	$ 560,576	$ (146)	$ 22,265
Balance, shares at Sep. 30, 2014	9,059,378	9,059,378				486,874