Segmented Information - Segment (loss) income (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total segment operating income	$ 450,000	$ 1,824,000	$ (1,277,000)	$ (394,000)
Net investment income	897,000	629,000	2,345,000	2,277,000
Net investment income	897,000	629,000	2,345,000	2,277,000
Net realized gains (losses)	1,001,000	(414,000)	760,000	(17,000)
(Loss) gain on change in fair value of equity investments	(38,000)	337,000	(23,000)	1,081,000
(Loss) gain on change in fair value of limited liability investments, at fair value	(3,356,000)	(131,000)	3,256,000	(1,592,000)
Net change in unrealized (loss) gain on private company investments	(343,000)	19,000	(324,000)	(136,000)
Other-than-temporary impairment loss	0	0	(75,000)	0
Interest expense not allocated to segments	(2,314,000)	(1,900,000)	(6,755,000)	(5,461,000)
Other income and expenses not allocated to segments, net	(1,863,000)	210,000	(6,224,000)	(5,415,000)
Amortization of intangible assets	(675,000)	(1,339,000)	(1,872,000)	(1,848,000)
Gain (loss) on change in fair value of debt	610,000	(1,450,000)	2,104,000	(2,511,000)
Gain on disposal of subsidiary	0	0	0	17,000
Equity in net (loss) income of investee	(126,000)	(339,000)	42,000	(623,000)
Loss from continuing operations before income tax expense (benefit)	(3,844,000)	(2,750,000)	(1,596,000)	(9,172,000)
Income tax expense (benefit)	162,000	(144,000)	(383,000)	300,000
Loss from continuing operations	(4,006,000)	(2,606,000)	(1,213,000)	(9,472,000)
Operating Segments
Segment Reporting Information [Line Items]
Total segment operating income	2,363,000	1,628,000	5,170,000	5,056,000
Extended Warranty | Operating Segments
Segment Reporting Information [Line Items]
Total segment operating income	1,579,000	1,155,000	3,181,000	3,091,000
Leased Real Estate | Operating Segments
Segment Reporting Information [Line Items]
Total segment operating income	$ 784,000	$ 473,000	$ 1,989,000	$ 1,965,000