Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues
Investment management fees	$ 64,891	$ 78,960	$ 204,254	$ 225,289
Distribution and service fees	15,587	23,671	52,820	70,049
Administration and transfer agent fees	11,614	14,804	37,233	41,819
Other income and fees	283	406	1,555	1,304
Total revenues	92,375	117,841	295,862	338,461
Operating Expenses
Employment expenses	33,504	35,246	102,719	105,756
Distribution and other asset-based expenses	21,717	29,180	69,900	96,139
Other operating expenses	11,165	11,288	51,403	34,952
Restructuring and severance	0	294	0	294
Depreciation and other amortization	910	713	2,562	2,040
Amortization expense	837	947	2,511	2,851
Total operating expenses	69,253	78,914	231,990	244,406
Operating Income	23,122	38,927	63,872	94,055
Other Income (Expense)
Realized and unrealized (loss) gain on investments, net	(2,082)	(1,039)	(1,194)	1,712
Other income, net	141	233	823	573
Total other (expense) income, net	(20,281)	(6,136)	(19,363)	3,435
Interest Income (Expense)
Interest expense	(138)	(149)	(382)	(412)
Interest and dividend income	324	326	906	1,053
Total interest income, net	3,125	2,399	8,885	5,375
Income Before Income Taxes	5,966	35,190	53,394	102,865
Income tax expense (benefit)	9,669	(1,805)	28,360	24,311
Net (Loss) Income	(3,703)	36,995	25,034	78,554
Noncontrolling interests	3,054	345	3,436	267
Net (Loss) Income Attributable to Common Stockholders	$ (649)	$ 37,340	$ 28,470	$ 78,821
(Loss) Earnings per share—Basic (in $ per share)	$ (0.07)	$ 4.10	$ 3.21	$ 8.65
(Loss) Earnings per Share—Diluted (in $ per share)	(0.07)	4.02	3.15	8.46
Cash Dividends Declared per Share (in $ per share)	$ 0.45	$ 0.45	$ 1.35	$ 0.90
Weighted Average Shares Outstanding—Basic (in shares)	8,775	9,096	8,876	9,115
Weighted Average Shares Outstanding—Diluted (in shares)	8,775	9,279	9,039	9,322
Consolidated Sponsored Investment Products [Member]
Operating Expenses
Other operating expenses	$ 1,120	$ 1,246	$ 2,895	$ 2,374
Other Income (Expense)
Realized and unrealized (loss) gain on investments, net	(17,619)	(5,330)	(18,271)	1,150
Interest Income (Expense)
Interest and dividend income	2,898	2,222	8,320	4,734
Consolidated Investment Product [Member]
Other Income (Expense)
Realized and unrealized (loss) gain on investments, net	(764)	0	(764)	0
Other income, net	43	0	43	0
Interest Income (Expense)
Interest and dividend income	$ 41	$ 0	$ 41	$ 0