Underwriting, Acquisition and Insurance Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Underwriting, Acquisition and Insurance Expenses [Abstract]
Gross commissions	$ 11,387	$ 8,756	$ 22,061	$ 17,135
Ceding commissions	(3,114)	(2,464)	(6,052)	(4,908)
Other operating expenses	8,164	6,227	16,044	12,690
Underwriting, acquisition, and insurance expenses	16,437	12,519	32,053	24,917
Salaries, bonuses and employee benefits	$ 7,100	$ 5,300	$ 13,900	$ 10,300