Reserve for Property and Casualty Insurance Claims and Claims Expense - Schedule of Reconciliation of Total Claims and Claims Expense Incurred and Paid by Coverage (Details) - Property and casualty - USD ($)
$ in Millions

Reserve for Property and Casualty Insurance Claims and Claims Expense - Schedule of Reconciliation of Total Claims and Claims Expense Incurred and Paid by Coverage (Details) - Property and casualty - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Increase (decrease) in claims and claims expense
Incurred	$ 37,454	$ 39,735	$ 41,070
Paid	(37,702)	$ (37,882)	$ (37,973)
Claims incurred and paid from before 2021
Increase (decrease) in claims and claims expense
Incurred	(15)
Paid	(612)
Auto insurance - liability coverage
Increase (decrease) in claims and claims expense
Incurred	14,575
Paid	(13,741)
Auto insurance - physical damage coverage
Increase (decrease) in claims and claims expense
Incurred	7,459
Paid	(7,584)
Homeowners insurance
Increase (decrease) in claims and claims expense
Incurred	8,852
Paid	(8,945)
Total auto and homeowners insurance
Increase (decrease) in claims and claims expense
Incurred	30,886
Paid	(30,270)
Other personal lines
Increase (decrease) in claims and claims expense
Incurred	2,281
Paid	(1,891)
Commercial lines
Increase (decrease) in claims and claims expense
Incurred	145
Paid	(667)
Other business lines
Increase (decrease) in claims and claims expense
Incurred	213
Paid	(254)
Protection Services
Increase (decrease) in claims and claims expense
Incurred	604
Paid	(598)
Run-off Property-Liability
Increase (decrease) in claims and claims expense
Incurred	123
Paid	(125)
Unallocated loss adjustment expenses (“ULAE”)
Increase (decrease) in claims and claims expense
Incurred	3,241
Paid	(3,400)
Other
Increase (decrease) in claims and claims expense
Incurred	(24)
Paid	$ 115