Investments Amortized cost, gross unrealized gains and losses, and estimated fair value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Other-than-temporary impairment loss	$ 316	$ 157	$ 10
Limited liability investment, at fair value	10,314	10,700
Other than Temporary Impairment Losses, Investments	316	157	$ 10
Total fixed maturities	53,746	62,136
Total equity investments	8,994	23,230
Total fixed maturities and equity investments	62,892	81,235
Gross Unrealized Gains, Fixed Maturities	33	133
Gross Unrealized Losses, Fixed Maturities	565	505
Estimated Fair Value, Fixed Maturities	53,214	61,764
Equity investments, cost	9,146	19,099
Gross Unrealized Gains	671	4,748
Gross Unrealized Losses	1,355	989
Estimated Fair Value, Fixed Maturities and Equity Investments	62,208	84,994
Limited liability investments	25,173	22,974
US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total fixed maturities	25,519	28,312
Gross Unrealized Gains, Fixed Maturities	0	22
Gross Unrealized Losses, Fixed Maturities	275	186
Estimated Fair Value, Fixed Maturities	25,244	28,148
Gross Unrealized Losses	275	186
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total fixed maturities	3,826	3,131
Gross Unrealized Gains, Fixed Maturities	3	1
Gross Unrealized Losses, Fixed Maturities	46	44
Estimated Fair Value, Fixed Maturities	3,783	3,088
Gross Unrealized Losses	46	44
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Total fixed maturities	7,784	8,610
Gross Unrealized Gains, Fixed Maturities	7	12
Gross Unrealized Losses, Fixed Maturities	128	116
Estimated Fair Value, Fixed Maturities	7,663	8,506
Gross Unrealized Losses	128	116
Asset-backed Securities, Securitized Loans and Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Total fixed maturities	2,279	3,468
Gross Unrealized Gains, Fixed Maturities	1	4
Gross Unrealized Losses, Fixed Maturities	11	5
Estimated Fair Value, Fixed Maturities	2,269	3,467
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total fixed maturities	14,338	18,615
Gross Unrealized Gains, Fixed Maturities	22	94
Gross Unrealized Losses, Fixed Maturities	105	154
Estimated Fair Value, Fixed Maturities	14,255	18,555
Gross Unrealized Losses	105	154
Common Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Total equity investments	7,419	21,426
Equity investments, cost	7,583	17,701
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	199	4,156
Gross Unrealized Losses, Equity Investments	363	431
Gross Unrealized Losses	363	431
Warrant [Member]
Schedule of Available-for-sale Securities [Line Items]
Total equity investments	1,575
Equity investments, cost	1,563
Gross Unrealized Losses	427	53
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total equity investments	8,994	23,230
Equity investments, cost	9,146	19,099
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	638	4,615
Gross Unrealized Losses, Equity Investments	790	484
Gross Unrealized Losses	790	484
US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities and Equity Investments	25,244	28,148
Fair Value, Inputs, Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Total equity investments	8,146	22,090
Fair Value, Inputs, Level 1 [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities	0	0
Fair Value, Inputs, Level 1 [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities	0	0
Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities		0
Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities	0	0
Fair Value, Inputs, Level 1 [Member] | Warrant [Member]
Schedule of Available-for-sale Securities [Line Items]
Total equity investments	727	664
Equity investments, cost	603	438
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	266	279
Gross Unrealized Losses, Equity Investments	142	53
Fair Value, Inputs, Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Limited liability investment, at fair value	10,314	10,700
Total equity investments	848	1,140
Estimated Fair Value, Fixed Maturities	53,214
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities	25,244	28,148
Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities	3,783	3,088
Fair Value, Inputs, Level 2 [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities	7,663	8,506
Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities	2,269	3,467
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Fixed Maturities	14,255	18,555
Fair Value, Inputs, Level 2 [Member] | Warrant [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Gain (Loss) on Securities	(112)	180
Total equity investments	848	1,140
Equity investments, cost	960	960
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	173	180
Gross Unrealized Losses, Equity Investments	$ 285	$ 0