Deferred Policy Acquisition Costs - Activity in Deferred Policy Acquisition Costs (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance at beginning of period				$ 12,011				$ 12,781	$ 12,011	$ 12,781	$ 13,290
Deferred policy acquisition costs									24,806	24,764	25,736
Amortization of policy acquisition costs	$ (6,959)	$ (6,153)	$ (6,210)	$ (5,589)	$ (6,097)	$ (6,452)	$ (6,472)	$ (6,513)	(24,911)	(25,534)	(26,245)
Net change									(105)	(770)	(509)
Balance at end of period	$ 11,906				$ 12,011				$ 11,906	$ 12,011	$ 12,781