Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount									$ 35,718	$ 0	$ 0
Goodwill and Intangible Asset Impairment										0	0
Revenues	$ 67,863	$ 64,331	$ 60,852	$ 59,581	$ 67,903	$ 61,741	$ 61,237	$ 54,525	252,627	245,406	236,268
Benefits and expenses	76,998	61,221	58,756	58,638	68,277	57,134	58,678	55,834	255,613	239,923	238,211
Federal income tax expense (benefit)	35,069	(339)	1,524	(1,113)	(490)	1,845	1,077	1,082	35,141	3,514	1,200
Net income (loss)	(44,204)	3,449	572	2,056	116	2,762	1,482	(2,391)	$ (38,127)	$ 1,969	$ (3,143)
Common Stock Class A [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (44,204)	$ 3,449	$ 572	$ 2,056	$ 116	$ 2,762	$ 1,482	$ (2,391)
Basic and diluted earnings (losses) per share common stock	$ (0.89)	$ 0.07	$ 0.01	$ 0.04	$ 0.00	$ 0.06	$ 0.03	$ (0.05)	$ (0.77)	$ 0.04	$ (0.06)
Common Stock Class B [Member]
Basic and diluted earnings (losses) per share common stock	$ (0.44)	$ 0.03	$ 0.01	$ 0.02	$ 0.00	$ 0.03	$ 0.01	$ (0.02)	$ (0.38)	$ 0.02	$ (0.03)
Home Service Insurance Segment [Member]
Goodwill and Intangible Asset Impairment									$ (4,631)	$ 0	$ 0
Revenues									61,126	60,091	59,211
Benefits and expenses									$ 66,725	$ 57,752	$ 54,673