Quarterly Financial Information (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2014
Revenues	$ 67,903,000	$ 61,741,000	$ 61,237,000	$ 54,525,000	$ 62,205,000	$ 58,124,000	$ 60,079,000	$ 55,860,000	$ 245,406,000	$ 236,268,000	$ 230,225,000
Benefits and expenses	68,277,000	57,134,000	58,678,000	55,834,000	64,193,000	58,039,000	60,693,000	55,286,000	239,923,000	238,211,000	232,175,000
Federal income tax expense (benefit)	(490,000)	1,845,000	1,077,000	1,082,000	208,000	(165,000)	1,153,000	2,000	3,514,000	1,200,000	4,020,000
Net income (loss)	116,000	2,762,000	1,482,000	(2,391,000)	(2,197,000)	250,000	(1,767,000)	572,000	$ 1,969,000	(3,143,000)	(5,970,000)	$ (5,970,000)
Common Class A [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 116,000	$ 2,762,000	$ 1,482,000	$ (2,391,000)	$ (2,197,000)	$ 250,000	$ (1,767,000)	$ 572,000
Basic earnings per share	$ 0.00	$ 0.06	$ 0.03	$ (0.05)	$ (0.04)	$ 0.01	$ (0.04)	$ 0.01
Diluted earnings per share	0.00	0.06	0.03	(0.05)	(0.04)	0.01	(0.04)	0.01
Common Class B [Member]
Basic earnings per share	0.00	0.03	0.01	(0.02)	(0.02)	0.00	(0.02)	0.01
Diluted earnings per share	$ 0.00	$ 0.03	$ 0.01	$ (0.02)	$ (0.02)	$ 0.00	$ (0.02)	$ 0.01
Restatement Adjustment [Member]
Benefits and expenses										(664,000)	(830,000)
Federal income tax expense (benefit)										228,000	295,000
Net income (loss)										$ 436,000	$ 535,000