Variable Interest Entities Assets and liabilities related to variable interest entities which are consolidated by the Company (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Oct. 12, 2017
Variable Interest Entity [Line Items]
Limited liability investments, at fair value	$ 26,015	$ 32,211
Investments in private companies, at adjusted cost	3,090	4,870
Cash and cash equivalents and restricted stock of continuing operations at beginning of period	14,619	5,377
Accrued expenses and other liabilities	14,786	10,359	$ 2,368
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Limited liability investments, at fair value	25,809	21,895
Investments in private companies, at adjusted cost	750	750
Cash and cash equivalents and restricted stock of continuing operations at beginning of period	351	220
Accrued investment income	217	107
Other receivable	48	0
Total Assets	27,175	22,972
Accrued expenses and other liabilities	252	97
Other Notes Payable	9,000	9,000
Total Liabilities	$ 9,252	$ 9,097