Reinsurance (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Reinsurance Retention Policy
Amount of risk reinsured in excess of stated retention	$ 3,300,000,000
Flood premiums ceded (percentage)			100.00%
Insurance commissions and fees under Flood Program	$ 431,000	$ 298,000	$ 764,000	$ 640,000
Document Period End Date			Jun. 30, 2020