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Reinsurance (List of Direct, Assumed, and Ceded Reinsurance Amounts) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Premiums earned:
Net	$ 812,283	$ 724,960
Loss and loss expenses incurred:
Net	494,236	413,401
Direct Assumed and Ceded Reinsurance Amounts [Member]
Premiums written:
Direct	1,001,049	908,774
Assumed	5,314	5,533
Ceded	(116,565)	(116,129)
Net	889,798	798,178
Premiums earned:
Direct	931,376	837,369
Assumed	5,528	5,676
Ceded	(124,621)	(118,085)
Net	812,283	724,960
Loss and loss expenses incurred:
Direct	528,588	441,507
Assumed	4,278	3,447
Ceded	(38,630)	(31,553)
Net	$ 494,236	$ 413,401

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