Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization Period Remaining	12 months	24 months
Client relationships, Gross Carrying Amount			$ 273
Client relationships, Accumulated Amortization	$ (1,448)	$ (1,359)
Client relationships, Net	95	184
Fund management contracts	1,250	1,250	$ 1,250
Gross Carrying Amount	2,793	2,793
Intangible assets—net	1,345	1,434
Client Relationships
Finite-Lived Intangible Assets [Line Items]
Client relationships, Gross Carrying Amount	1,543	1,543
Client relationships, Accumulated Amortization	(1,448)	(1,359)
Client relationships, Net	95	184
Fund Management Contracts Member
Finite-Lived Intangible Assets [Line Items]
Fund management contracts	$ 1,250	$ 1,250