Non-Insurance Revenues from Contracts with Customers (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenue from External Customer [Line Items]
Deferred non-insurance warranty revenue	$ 4,138	$ 4,530	$ 4,694
Contract with customer, liability, revenue recognized	1,400	1,400
Deferred non-insurance warranty acquisition expense	3,220	3,525	$ 3,661
Amortization of deferred sales commissions	1,200	1,200
Capitalized Commission Costs
Revenue from External Customer [Line Items]
Deferred non-insurance warranty acquisition expense	3,200	3,500
Capitalized Administrator Service Costs
Revenue from External Customer [Line Items]
Deferred non-insurance warranty acquisition expense	$ 61	$ 68