Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total Attributed To Shareholders	Non- controlling Interest	Series D preferred stock	Series D preferred stock Preferred Stock	Series D preferred stock Total Attributed To Shareholders
Balance (in shares) at Dec. 31, 2014		8,975,833				575,441
Balance at Dec. 31, 2014	$ 563,352	$ 96	$ 1,148,908	$ (507,521)	$ (242)	$ (77,699)	$ 563,542	$ (190)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	34,930			35,106			35,106	(176)
Net unrealized gain (loss)on securities available-for-sale	(358)				(358)		(358)
Foreign currency translation adjustment	(434)				(434)		(434)
Activity of noncontrolling interests, net				(199)			(199)	199
Cash dividends declared	(16,009)		(16,009)				(16,009)
Repurchase of common shares (in shares)		(638,703)				(638,703)
Repurchase of common shares	(80,000)					$ (80,000)	(80,000)
Issuance of common shares related to employee stock transactions (in shares)		61,814
Issuance of common shares related to employee stock transactions	842		842				842
Taxes paid on stock-based compensation	(5,080)		(5,080)				(5,080)
Stock-based compensation	11,116		11,116				11,116
Excess tax benefits (tax deficiencies) from stock-based compensation	1,098		1,098				1,098
Balance (in shares) at Dec. 31, 2015		8,398,944				1,214,144
Balance at Dec. 31, 2015	509,457	$ 96	1,140,875	(472,614)	(1,034)	$ (157,699)	509,624	(167)
Balance at Dec. 31, 2014	23,071
Increase (Decrease) in Redeemable Noncontrolling Interest [Roll Forward]
Net income (loss)	(4,259)
Activity of noncontrolling interests, net	55,052
Balance at Dec. 31, 2015	73,864
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	48,502			48,502			48,502	0
Net unrealized gain (loss)on securities available-for-sale	241				241		241
Foreign currency translation adjustment	569				569		569
Activity of noncontrolling interests, net				(167)			(167)	167
Cash dividends declared	(13,015)		(13,015)				(13,015)
Repurchase of common shares (in shares)		(2,572,417)				(2,015,901)
Repurchase of common shares	(233,757)	$ (6)	(47,204)			$ (186,547)	(233,757)
Issuance of common shares related to employee stock transactions (in shares)		62,486
Issuance of common shares related to employee stock transactions	1,055	$ 1	1,054				1,055
Taxes paid on stock-based compensation	(1,530)		(1,530)				(1,530)
Stock-based compensation	11,449		11,449				11,449
Excess tax benefits (tax deficiencies) from stock-based compensation	(1,298)		(1,298)				(1,298)
Balance (in shares) at Dec. 31, 2016		5,889,013				3,230,045
Balance at Dec. 31, 2016	321,673	$ 91	1,090,331	(424,279)	(224)	$ (344,246)	321,673	0
Increase (Decrease) in Redeemable Noncontrolling Interest [Roll Forward]
Net income (loss)	261
Activity of noncontrolling interests, net	(36,859)
Balance at Dec. 31, 2016	37,266
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment for adoption of ASU 2016-09	1,051			1,051			1,051
Net income (loss)	38,519			37,012			37,012	1,507
Net unrealized gain (loss)on securities available-for-sale	(388)				(388)		(388)
Foreign currency translation adjustment	12				12		12
Activity of noncontrolling interests, net	$ 15,160							15,160
Issuance of stock, net of offering costs (in shares)	1,260,169	1,046,500								1,150,000
Issuance of stock, net of offering costs	$ 109,327	$ 11	109,316				109,327		$ 110,843	$ 110,843	$ 110,843
Dividends	(8,337)		(8,337)				(8,337)
Issuance of common stock for acquisition of business (in shares)		213,669
Issuance of common stock for acquisition of business	21,740	$ 2	21,738				21,740
Cash dividends declared	$ (13,545)		(13,545)				(13,545)
Repurchase of common shares (in shares)	(66,244)	(66,244)				(66,244)
Repurchase of common shares	$ (7,502)					$ (7,502)	(7,502)
Issuance of common shares related to employee stock transactions (in shares)		76,707
Issuance of common shares related to employee stock transactions	841	$ 1	840				841
Taxes paid on stock-based compensation	(3,499)		(3,499)				(3,499)
Stock-based compensation	19,329		19,329				19,329
Balance (in shares) at Dec. 31, 2017		7,159,645				3,296,289				1,150,000
Balance at Dec. 31, 2017	605,224	$ 105	$ 1,216,173	$ (386,216)	$ (600)	$ (351,748)	$ 588,557	$ 16,667		$ 110,843
Increase (Decrease) in Redeemable Noncontrolling Interest [Roll Forward]
Net income (loss)	1,420
Activity of noncontrolling interests, net	(34,508)
Balance at Dec. 31, 2017	$ 4,178