Consolidation - Revenue and Expenses of Consolidated Investment Product (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income:
Realized and unrealized gain, net	$ 297	$ (658)
Interest Income	188	273
Total revenues	79,776	80,295
Expenses:
Other operating expenses	13,226	10,765
Net Income Attributable to Common Stockholders	10,943	12,363
Consolidated Investment Product
Income:
Realized and unrealized gain, net	718	2,235
Interest Income	4,161	2,206
Total revenues	4,879
Expenses:
Other operating expenses	65	56
Interest expense	2,857	$ 732
Total Expense	2,922
Net Income Attributable to Common Stockholders	$ 1,957