Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenues
Investment management fees	$ 58,192	$ 68,867	$ 115,836	$ 139,363
Distribution and service fees	12,167	17,635	24,645	37,233
Administration and transfer agent fees	9,499	12,577	19,497	25,619
Other income and fees	227	577	402	1,272
Total revenues	80,085	99,656	160,380	203,487
Operating Expenses
Employment expenses	33,065	33,593	69,042	69,215
Distribution and other asset-based expenses	17,432	23,676	35,533	48,183
Other operating expenses	12,457	23,512	23,222	40,238
Restructuring and severance	2,391	0	2,391	0
Depreciation and other amortization	776	873	1,638	1,652
Amortization expense	603	837	1,254	1,674
Total operating expenses	71,342	83,448	138,887	162,737
Operating Income	8,743	16,208	21,493	40,750
Other Income (Expense)
Realized and unrealized gain on investments, net	3,281	343	2,623	888
Other (expense) income, net	(15)	247	213	682
Total other income (expense), net	6,944	(2,652)	9,044	918
Interest Income (Expense)
Interest and dividend income	619	302	892	582
Total interest (expense) income, net	(900)	3,279	3,676	5,760
Income Before Income Taxes	14,787	16,835	34,213	47,428
Income tax expense	6,087	7,823	13,643	18,691
Net Income	8,700	9,012	20,570	28,737
Noncontrolling interests	(612)	765	(119)	382
Net Income Attributable to Common Stockholders	$ 8,088	$ 9,777	$ 20,451	$ 29,119
Earnings per share—Basic (in $ per share)	$ 0.99	$ 1.10	$ 2.48	$ 3.26
Earnings per Share—Diluted (in $ per share)	0.97	1.08	2.43	3.20
Cash Dividends Declared per Share (in $ per share)	$ 0.45	$ 0.45	$ 0.90	$ 0.9
Weighted Average Shares Outstanding—Basic (in shares)	8,170	8,889	8,257	8,927
Weighted Average Shares Outstanding—Diluted (in shares)	8,314	9,037	8,410	9,094
Parent [Member]
Interest Income (Expense)
Interest expense	$ (129)	$ (121)	$ (261)	$ (244)
Consolidated Sponsored Investment Products [Member]
Operating Expenses
Other operating expenses	777	957	1,910	1,775
Other Income (Expense)
Realized and unrealized gain on investments, net	3,097	(3,242)	3,392	(652)
Interest Income (Expense)
Interest and dividend income	1,696	3,098	4,657	5,422
Consolidated Investment Product [Member]
Operating Expenses
Other operating expenses	3,841	0	3,897	0
Other Income (Expense)
Realized and unrealized gain on investments, net	581	0	2,816	0
Interest Income (Expense)
Interest expense	(5,668)	0	(6,400)	0
Interest and dividend income	$ 2,582	$ 0	$ 4,788	$ 0