CONDENSED CONSOLIDATED STATEMENTS OF EQUITY UNAUDITED - USD ($) $ in Thousands	Noncontrolling Interests [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Deficit) [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]	Total	Redeemable Noncontrolling Interests [Member]
Balance at Dec. 31, 2014	$ 2,734	$ 33	$ 291,681	$ 602,950	$ 25,014	$ (394,617)	$ 527,795	$ 68,334
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemptions of redeemable noncontrolling interests	0	0	0	0	0	0	0	(441)
Contributions from redeemable noncontrolling interests	0	0	0	0	0	0	0	336
Consolidation of a consolidated feeder fund and a partnership	0	0	0	0	0	0	0	996
Deconsolidation of offshore fund	0	0	0	0	0	0	0	(63,256)
Net income (loss)	(45)	0	0	48,877	0	0	48,832	(26)
Net unrealized losses on securities available for sale, net of income tax expense	0	0	0	0	(681)	0	(681)	0
Amounts reclassified from accumulated other comprehensve income, net of income tax expense (benefit)	0	0	0	0	(41)	0	(41)	0
Foreign currency translation	0	0	0	0	13	0	13	0
Dividends declared	0	0	0	(3,596)	0	0	(3,596)	0
Stock based compensation expense	0	0	4,544	0	0	0	4,544	0
Exercise of stock options including tax benefit ($102)	0	0	1,269	0	0	0	1,269	0
Purchase of treasury stock	0	0	0	0	0	(11,016)	(11,016)	0
Balance at Jun. 30, 2015	$ 2,689	33	297,494	648,231	24,305	(405,633)	567,119	$ 5,943
Balance at Dec. 31, 2015		33	345	(34,224)	9,115	(251,596)	(276,327)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		0	0	53,568	0	0	53,568
Net unrealized losses on securities available for sale, net of income tax expense		0	0	0	(85)	0	(85)
Amounts reclassified from accumulated other comprehensve income, net of income tax expense (benefit)		0	0	0	(98)	0	(98)
Foreign currency translation		0	0	0	(93)	0	(93)
Dividends declared		0	0	(1,189)	0	0	(1,189)
Stock based compensation expense		0	2,072	0	0	0	2,072
Purchase of treasury stock		0	0	0	0	(1,331)	(1,331)
Balance at Jun. 30, 2016		$ 33	$ 2,417	$ 18,155	$ 8,839	$ (252,927)	$ (223,483)