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Reinsurance (Ceded Premiums and Losses Related to Flood Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Ceded premiums written	$ (111,303)	$ (104,651)	$ (211,305)	$ (200,596)
Ceded premiums earned	(103,471)	(98,499)	(205,497)	(196,528)
Ceded loss and loss expenses incurred	(59,064)	(27,050)	$ (102,407)	(71,029)
National Flood Insurance Program [Member]
Percentage of NFIP claims ceded by federal government			100.00%
Ceded premiums written	(71,574)	(66,341)	$ (131,587)	(123,010)
Ceded premiums earned	(63,804)	(60,143)	(126,067)	(119,134)
Ceded loss and loss expenses incurred	$ (21,063)	$ (10,261)	$ (34,749)	$ (25,980)

X

- Definition

Percentage of unpaid NFIP claims ceded to federal government.

+ References

No definition available.

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Amount of earned premiums ceded to other entities.

+ References

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-Publisher FASB
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-SubTopic 235
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Amount of written premiums ceded to other entities.

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Amount of reduction of provision for policy benefits and costs incurred for policies ceded.

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