Reserves for Losses and Loss Settlement Expenses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross liability for losses and loss settlement expenses at beginning of year	$ 1,514,265	$ 1,578,131
Ceded losses and loss settlement expenses	(112,900)	(131,843)
Net liability for losses and loss settlement expenses at beginning of year	1,401,365	1,446,288
Losses and loss settlement expenses incurred for claims occurring during
Current year	137,090	701,064
Prior years	(6,714)	(48,909)
Total incurred	130,376	652,155
Losses and loss settlement expense payments for claims occurring during
Current year	23,423	277,115
Prior years	144,042	419,963
Total paid	167,465	697,078
Net liability for losses and loss settlement expenses at end of year	1,364,276	1,401,365
Ceded loss and loss settlement expenses	123,714	112,900
Gross liability for losses and loss settlement expenses at end of period	$ 1,487,991	$ 1,514,265