Schedule IV - Reinsurance (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Gross Amount									$ 951,302	$ 812,924	$ 660,260
Ceded to Other Companies									(88,738)	(35,499)	(10,768)
Assumed from Other Companies									0	0	0
Net premiums earned	$ 222,339	$ 222,258	$ 211,471	$ 206,496	$ 207,671	$ 203,473	$ 188,490	$ 177,791	$ 862,564	$ 777,425	$ 649,492
Assumed Premiums as a Percentage of Net Premiums									0.00%	0.00%	0.00%