Reinsurance - Quota Share Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effects of Reinsurance [Line Items]
Ceded losses incurred	$ 77,975	$ 11,400	$ 6,829
Quota Share Reinsurance Agreements
Effects of Reinsurance [Line Items]
Ceded premiums written and earned, net of profit commission	167,930	111,550	108,337
Ceded losses incurred	78,012	11,395	6,543
Ceding commisisons	48,077	48,793	51,201
Profit commission	$ 72,452	$ 139,179	$ 147,667