Accounts Receivable (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable
Premiums receivable	$ 42,988,000	$ 46,974,000
Other receivables	3,169,000	3,166,000
Total accounts receivable	46,157,000	50,140,000
Less: Allowance for doubtful accounts	0	0
Accounts receivable, net	46,157,000	50,140,000
Provision for doubtful accounts	$ 0	$ 0	$ 0
Premiums Receivable
Accounts Receivable
Threshold period unpaid for write-off of mortgage insurance premiums (more than)	90 days