Reserves for Unpaid Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 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	126,471	96,673
Prior years	(8,350)	(5,722)
Total net losses and loss adjustment expenses incurred	118,121	90,951
Payments:
Current year	12,258	4,095
Prior years	53,808	52,056
Total payments	66,066	56,151
Net reserves for unpaid losses and loss adjustment expenses, end of period	365,818	302,293
Reinsurance recoverable on unpaid losses	63,714	63,521
Gross reserves for unpaid losses and loss adjustment expenses, end of period	$ 429,532	$ 365,814