General - Effects of Reinsurance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Premiums Written
Direct	$ 1,057,100	$ 1,032,100	$ 3,109,500	$ 2,958,400
Premiums Earned
Ceded	23,000	17,000	57,000	48,000
Net	996,939	940,941	2,947,000	2,783,682
Property & Casualty
Premiums Written
Direct	1,049,088	1,024,753	3,086,222	2,934,777
Ceded	(22,805)	(17,322)	(57,776)	(48,750)
Assumed	138	161	10,582	13,048
Net	1,026,421	1,007,592	3,039,028	2,899,075
Premiums Earned
Direct	1,009,829	947,458	2,974,651	2,800,357
Ceded	(22,825)	(17,175)	(57,383)	(48,335)
Assumed	2,684	3,322	8,142	9,912
Net	$ 989,688	$ 933,605	$ 2,925,410	$ 2,761,934