Reinsurance - Effect of Reinsurance Programs (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Ceded Credit Risk [Line Items]
Direct premiums written	$ 1,024,660,000	$ 1,108,513,000	$ 1,132,338,000
Ceded premiums written	(48,279,000)	(87,201,000)	(56,132,000)
Total net premiums written	983,447,000	1,033,509,000	1,086,585,000
Direct premiums earned	1,144,361,000	1,286,527,000	1,244,870,000
Assumed premiums earned	7,066,000	12,214,000	10,382,000
Ceded premiums earned	(114,244,000)	(183,420,000)	(109,903,000)
Total net premiums earned	1,037,183,000	1,115,321,000	1,145,349,000
Ceding commissions earned	31,745,000	53,654,000	48,659,000
Ceded losses	(4,570,000)	58,266,000	5,859,000
Deferred ceding commissions	38,600,000	52,500,000
Mortgage insurance
Ceded Credit Risk [Line Items]
Direct premiums written	984,995,000	1,085,670,000	1,120,996,000
Assumed premiums written	7,066,000	12,197,000	10,379,000
Ceded premiums written	(47,515,000)	(86,912,000)	(55,925,000)
Direct premiums earned	1,104,696,000	1,263,684,000	1,233,528,000
Assumed premiums earned	7,066,000	12,214,000	10,382,000
Ceded premiums earned	(113,480,000)	(183,131,000)	(109,696,000)
Total net premiums earned	998,282,000	1,092,767,000	1,134,214,000
Title insurance
Ceded Credit Risk [Line Items]
Direct premiums written	39,665,000	22,843,000	11,342,000
Ceded premiums written	(764,000)	(289,000)	(207,000)
Direct premiums earned	39,665,000	22,843,000	11,342,000
Ceded premiums earned	$ (764,000)	$ (289,000)	$ (207,000)