Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) arising during the period, before income taxes	$ (1,101)	$ 3,369	$ (7,193)	$ 4,987
Income taxes	232	(1,179)	1,511	(1,745)
Unrealized gains (losses) arising during the period, net of income tax	(869)	2,190	(5,682)	3,242
Less reclassification adjustment [Abstract]
Net realized investment gains (losses)	185	24	240	(8)
Income taxes	(38)	(8)	(50)	3
Reclassification adjustment included in net income	147	16	190	(5)
Other comprehensive income (loss)	(1,016)	2,174	(5,872)	3,247
Fixed maturities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) arising during the period, before income taxes	(1,101)	2,792	(7,193)	3,489
Equity securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) arising during the period, before income taxes	$ 0	$ 577	$ 0	$ 1,498