Underwriting Information - Gross Written Premiums by Product (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Gross written premiums
Amount	$ 218,689	$ 129,359	$ 389,623	$ 232,936
% of GWP	100.00%	100.00%	100.00%	100.00%
Residential Earthquake
Gross written premiums
Amount	$ 54,090	$ 42,192	$ 100,426	$ 78,090
% of GWP	24.70%	32.60%	25.80%	33.50%
Fronting Premiums - N10K
Gross written premiums
Amount	$ 42,154		$ 71,999
% of GWP	19.30%	0.00%	18.50%	0.00%
Commercial Earthquake
Gross written premiums
Amount	$ 33,103	$ 17,343	$ 58,247	$ 38,619
% of GWP	15.10%	13.40%	14.90%	16.60%
Inland Marine
Gross written premiums
Amount	$ 23,134	$ 11,681	$ 41,371	$ 19,515
% of GWP	10.60%	9.00%	10.60%	8.40%
Specialty Homeowners
Gross written premiums
Amount	$ 13,891	$ 19,135	$ 30,176	$ 33,138
% of GWP	6.40%	14.80%	7.70%	14.20%
Commercial All Risk
Gross written premiums
Amount	$ 21,213	$ 14,976	$ 31,791	$ 23,165
% of GWP	9.70%	11.60%	8.20%	9.90%
Hawaii Hurricane
Gross written premiums
Amount	$ 8,240	$ 7,788	$ 15,154	$ 13,925
% of GWP	3.80%	6.00%	3.90%	6.00%
Residential Flood
Gross written premiums
Amount	$ 3,583	$ 2,865	$ 6,577	$ 5,149
% of GWP	1.60%	2.20%	1.70%	2.20%
Others
Gross written premiums
Amount	$ 19,281	$ 13,379	$ 33,882	$ 21,335
% of GWP	8.80%	10.40%	8.70%	9.20%