Related Party Transactions - Schedule of AmTrust Quota Share Arrangement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Related Party Transaction [Line Items]
Net premiums earned	$ 13,312	$ 21,308	$ 25,076	$ 52,523
Net loss and LAE	5,327	(11,008)	2,968	(32,094)
Commission and other acquisition expenses	(6,899)	(8,154)	(12,841)	(20,127)
Quota Share Reinsurance Agreements | AmTrust Financial Services, Inc.
Related Party Transaction [Line Items]
Gross and net premiums written	(1,757)	(4,705)	(4,219)	(4,705)
Net premiums earned	6,350	9,540	11,874	28,224
Net loss and LAE	6,574	(4,970)	5,630	(19,015)
Commission and other acquisition expenses	$ (2,447)	$ (3,780)	$ (4,634)	$ (10,774)