Unpaid Losses and Loss Adjustment Expenses - Changes in the Liability for Unpaid Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves - beginning of period	$ 97,981	$ 83,662	$ 92,807	$ 87,896
Less: reinsurance recoverables on unpaid losses	21,396	20,467	29,685	20,066
Plus: deferred gain on ADC	0	(4,933)	0	(4,933)	$ (481)	$ (5,677)	$ (2,412)	$ 0
Net reserves - beginning of period	77,066	65,607	68,799	67,830
Add: incurred losses and LAE, net of reinsurance:
Current period	12,154	13,153	36,619	40,079
Prior period	2,703	3,401	7,076	4,871
Total net incurred losses and LAE	14,857	16,554	43,695	44,950
Deduct: loss and LAE payments, net of reinsurance:
Current period	4,933	5,423	8,675	11,448
Prior period	6,515	7,877	23,344	32,471
Total net loss and LAE payments	11,448	13,300	32,019	43,919
Net reserves - end of period	80,475	68,861	80,475	68,861
Plus: reinsurance recoverables on unpaid losses	16,862	27,118	16,862	27,118
Gross reserves - end of period	$ 97,337	$ 91,046	$ 97,337	$ 91,046