Pension Plans and Other Postretirement Benefits - Benefit Obligations and Plan Assets (Details) - Pension Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Change in benefit obligation:
Benefit obligation, beginning of year	$ 4,349	$ 4,736
Interest cost	221	222	$ 231
Actuarial loss (gain)	123	(262)
Benefit payments	(356)	(347)
Benefit obligation, end of year	4,337	4,349	4,736
Change in plan assets:
Beginning balance	5,188	5,379
Actual return on plan assets	433	133
Employer contributions	22	23
Benefit payments	(356)	(347)
Ending balance	5,287	5,188	$ 5,379
Funded status	950	839
Assets (liabilities) recognized on the consolidated balance sheet
Noncurrent assets reflected in other assets	1,137	1,030
Current liabilities reflected in accrued expenses and other current liabilities	(22)	(22)
Noncurrent liabilities reflected in other long-term liabilities	(165)	(169)
Net assets	$ 950	$ 839