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Reinsurance (List of Direct, Assumed, and Ceded Reinsurance Amounts) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Premiums earned:
Net	$ 902,336	$ 812,283
Loss and loss expenses incurred:
Net	567,438	494,236
Direct Assumed and Ceded Reinsurance Amounts [Member]
Premiums written:
Direct	1,132,760	1,001,049
Assumed	5,394	5,314
Ceded	(138,386)	(116,565)
Net	999,768	889,798
Premiums earned:
Direct	1,032,228	931,376
Assumed	6,290	5,528
Ceded	(136,182)	(124,621)
Net	902,336	812,283
Loss and loss expenses incurred:
Direct	613,229	528,588
Assumed	5,255	4,278
Ceded	(51,046)	(38,630)
Net	$ 567,438	$ 494,236

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