Reinsurance - Quota Share Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effects of Reinsurance [Line Items]
Ceded losses incurred	$ 11,400	$ 6,829	$ 21,201
Quota Share Reinsurance Agreements, Excluding Captives
Effects of Reinsurance [Line Items]
Ceded premiums written and earned, net of profit commission	111,550	108,337	120,974
Ceded losses incurred	11,395	6,543	22,336
Ceding commisisons	48,793	51,201	49,321
Profit commission	$ 139,179	$ 147,667	$ 125,629