Reserve for Property and Casualty Insurance Claims and Claims Expense - Schedule of Average Annual Percentage Payout of Incurred Claims by Age, Net of Recoverables (Details)	Dec. 31, 2024
Auto insurance – liability coverage
Claims Development [Line Items]
1 year	33.30%
2 years	32.50%
3 years	15.20%
4 years	8.80%
5 years	4.90%
After 5 years	5.30%
Auto insurance - physical damage coverage
Claims Development [Line Items]
1 year	93.10%
2 years	7.00%
3 years	(0.60%)
4 years	(0.20%)
5 years	0.00%
After 5 years	0.70%
Homeowners
Claims Development [Line Items]
1 year	66.60%
2 years	25.30%
3 years	3.90%
4 years	1.60%
5 years	0.80%
After 5 years	1.80%