Segmented Information - Segment (loss) income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Total segment operating income	$ (1,622)	$ (899)
Net investment income	719	699
Net realized gains	208	315
(Loss) gain on change in fair value of equity investments	(597)	78
Gain on change in fair value of limited liability investments, at fair value	1,899	4,265
Net change in unrealized (loss) gain on private company investments	(670)	19
Other-than-temporary impairment loss	(117)	(75)
Interest expense not allocated to segments	(2,153)	(2,102)
Other income and expenses not allocated to segments, net	(3,030)	(1,764)
Amortization of intangible assets	(574)	(521)
Gain on change in fair value of debt	2,645	576
Equity in net loss of investee	0	(33)
(Loss) income before income tax expense (benefit)	(223)	2,476
Income tax expense (benefit)	170	(713)
Income from continuing operations	(393)	3,189
Operating Segments
Segment Reporting Information [Line Items]
Total segment operating income	1,447	1,019
Extended Warranty | Operating Segments
Segment Reporting Information [Line Items]
Total segment operating income	850	567
Leased Real Estate | Operating Segments
Segment Reporting Information [Line Items]
Total segment operating income	$ 597	$ 452