Consolidated Statements of Changes in Stockholders' Equity - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Treasury Stock [Member]	Total Attributed To Shareholders [Member]	Non-controlling Interest [Member]	Redeemable Non-controlling Interest [Member]
Beginning Balance (in shares) at Dec. 31, 2012		7,826,674				245,000
Beginning Balance at Dec. 31, 2012	$ 244,471,000	$ 81,000	$ 942,825,000	$ (680,411,000)	$ (287,000)	$ (17,734,000)	$ 244,474,000	$ (3,000)	$ 3,163,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	75,131,000			75,190,000			75,190,000	(59,000)	1,999,000
Net unrealized loss on securities available-for-sale	56,000				56,000		56,000
Foreign currency translation adjustment	81,000				81,000		81,000
Activity of noncontrolling interests, net	1,477,000								37,024,000
Issuance of common stock, net	191,578,000	$ 13,000	191,565,000				191,578,000
Issuance of common stock, net (in shares)		1,298,386
Cash dividends declared	0
Repurchase of common shares	(19,704,000)					$ (19,704,000)	(19,704,000)
Repurchase of common shares (in shares)		105,000				105,000
Issuance of common stock related to employee stock transactions	633,000	$ 1,000	632,000				633,000
Issuance of common stock related to employee stock transactions (in shares)		85,461
Taxes paid on stock-based compensation	(7,513,000)		(7,513,000)				(7,513,000)
Stock-based compensation	7,657,000		7,657,000				7,657,000
Excess tax benefits from stock-based compensation	478,000		478,000				478,000
Ending Balance (in shares) at Dec. 31, 2013		9,105,521				350,000
Ending Balance at Dec. 31, 2013	492,868,000	$ 95,000	1,135,644,000	(605,221,000)	(150,000)	$ (37,438,000)	492,930,000	(62,000)	42,186,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	97,572,000			97,700,000			97,700,000	(128,000)	(607,000)
Net unrealized loss on securities available-for-sale	124,000				124,000		124,000
Foreign currency translation adjustment	(216,000)				(216,000)		(216,000)
Activity of noncontrolling interests, net	(47,165,000)								(18,508,000)
Cash dividends declared	(12,451,000)		(12,451,000)				(12,451,000)
Repurchase of common shares	$ (40,261,000)					$ (40,261,000)	(40,261,000)
Repurchase of common shares (in shares)	225,441	225,441				225,441
Issuance of common stock related to employee stock transactions	$ 1,417,000	$ 1,000	1,416,000				1,417,000
Issuance of common stock related to employee stock transactions (in shares)		95,753
Taxes paid on stock-based compensation	(9,512,000)		(9,512,000)				(9,512,000)
Stock-based compensation	9,006,000		9,006,000				9,006,000
Excess tax benefits from stock-based compensation	24,805,000		24,805,000				24,805,000
Ending Balance (in shares) at Dec. 31, 2014		8,975,833				575,441
Ending Balance at Dec. 31, 2014	563,352,000	$ 96,000	1,148,908,000	(507,521,000)	(242,000)	$ (77,699,000)	563,542,000	(190,000)	23,071,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	34,930,000			35,106,000			35,106,000	(176,000)	(4,259,000)
Net unrealized loss on securities available-for-sale	(358,000)				(358,000)		(358,000)
Foreign currency translation adjustment	(434,000)				(434,000)		(434,000)
Activity of noncontrolling interests, net	(648,000)			(199,000)			(199,000)	199,000	55,052,000
Cash dividends declared	(16,009,000)		(16,009,000)				(16,009,000)
Repurchase of common shares	$ (80,000,000)					$ (80,000,000)	(80,000,000)
Repurchase of common shares (in shares)	638,703	638,703				638,703
Issuance of common stock related to employee stock transactions	$ 842,000		842,000				842,000
Issuance of common stock related to employee stock transactions (in shares)		61,814
Taxes paid on stock-based compensation	(5,080,000)		(5,080,000)				(5,080,000)
Stock-based compensation	11,116,000		11,116,000				11,116,000
Excess tax benefits from stock-based compensation	1,098,000		1,098,000				1,098,000
Ending Balance (in shares) at Dec. 31, 2015		8,398,944				1,214,144
Ending Balance at Dec. 31, 2015	$ 509,457,000	$ 96,000	$ 1,140,875,000	$ (472,614,000)	$ (1,034,000)	$ (157,699,000)	$ 509,624,000	$ (167,000)	$ 73,864,000