Reinsurance (Details) - USD ($)	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Reinsurance Retention Policy
Amount of risk reinsured in excess of stated retention	$ 3,200,000,000
Flood premiums ceded (percentage)	100.00%
Insurance commissions and fees under Flood Program	$ 333,000	$ 342,000

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