Loss And Loss Adjustment Expense Reserves - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Unusual or Infrequent Item, or Both [Line Items]
Prior years	$ (35,948)	$ 47,281	$ (26,091)
Pre-tax catastrophe losses	239,000	102,000	104,000
Catastrophe
Unusual or Infrequent Item, or Both [Line Items]
Pre-tax catastrophe losses	247,000	101,000	109,000
Prior year claims and claim adjustment expense payments, favorable (unfavorable) outcome	$ 8,000	$ (1,000)	$ 5,000