Reserves for Unpaid Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Net reserves for unpaid losses and loss adjustment expenses, beginning of year	$ 313,763	$ 267,493
Incurred losses and loss adjustment expenses:
Current year	81,127	62,389
Prior years	(7,816)	(3,523)
Total net losses and loss adjustment expenses incurred	73,311	58,866
Payments:
Current year	5,530	1,858
Prior years	36,100	33,309
Total payments	41,630	35,167
Net reserves for unpaid losses and loss adjustment expenses, end of period	345,444	291,192
Reinsurance recoverable on unpaid losses	61,989	53,373
Gross reserves for unpaid losses and loss adjustment expenses, end of period	$ 407,433	$ 344,565