Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions		12 Months Ended
Apr. 01, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Exposure to earthquake loss	$ 77.1
Reduction in premiums written, net		$ 128.0

Amount, after premiums ceded to other entities and premiums assumed by the entity, of decrease (increase) in unearned premiums.

No definition available.

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