Casualty, Environmental and Other Reserves - Schedule of Claims Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Loss Contingency Accrual [Roll Forward]
Balance at beginning of period	$ 462	$ 440	$ 436
Charged to Expense	199	168	165
Payments	(182)	(146)	(161)
Balance at end of period	479	462	440
Casualty Reserves
Loss Contingency Accrual [Roll Forward]
Balance at beginning of period	208	195	194
Charged to Expense	67	72	69
Payments	(62)	(59)	(68)
Balance at end of period	213	208	195
Environmental Reserves
Loss Contingency Accrual [Roll Forward]
Balance at beginning of period	151	154	161
Charged to Expense	32	28	29
Payments	(27)	(31)	(36)
Balance at end of period	156	151	154
Other Reserves
Loss Contingency Accrual [Roll Forward]
Balance at beginning of period	103	91	81
Charged to Expense	100	68	67
Payments	(93)	(56)	(57)
Balance at end of period	$ 110	$ 103	$ 91