Historical Loss and LAE Development - Schedule of Reconciliation of Unpaid Losses and Settlement Expenses (LAE) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Unpaid losses and LAE at beginning of year
Gross	$ 2,043,555	$ 1,750,049
Ceded	(608,086)	(443,729)
Net	1,435,469	1,306,320
Increase (decrease) in incurred losses and LAE
Current accident year	150,999	142,013
Prior accident years	(45,475)	(37,121)
Total incurred	105,524	104,892
Loss and LAE payments for claims incurred
Current accident year	(7,875)	(5,962)
Prior accident years	(82,851)	(64,896)
Total paid	(90,726)	(70,858)
Net unpaid losses and LAE at March 31	1,450,267	1,340,354
Unpaid losses and LAE at March 31
Gross	2,081,712	1,795,275
Ceded	(631,445)	(454,921)
Net unpaid losses and LAE at March 31	$ 1,450,267	$ 1,340,354