Retirement Benefits Amounts in Paragraphs - Retirement Benefits (Details 9) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 669	$ 657	$ 634
Pension and post-retirement benefits disclosures (Amounts in paragraphs)
Accumulated benefit obligation for all defined benefit pension plans	$ 29,100	28,700
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Actual Percent Return On Plan Assets	11.30%
Yearly Discount Rate change in basis points	(15)
Pension Benefits
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 97
Defined Benefit Plan, Plan Assets, Contributions by Employer	99	96
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Defined Benefit Plan, Plan Assets, Contributions by Employer, Voluntary Contributions	0
OPB contributions
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	34
Defined Benefit Plan, Plan Assets, Contributions by Employer	31	33
U.S. equities
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 0	0
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Frequency	daily, monthly or quarterly
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	90 days
International Equity Securities [Member]
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 0	0
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Frequency	daily, monthly or quarterly
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	90 days
Fixed Income Funds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 0	0
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Frequency	daily, monthly or quarterly
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	2 days
Private Equity Funds [Member]
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 1,200	1,600
Average investment term, alternative investments	10 years
Real Estate Funds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 124	24
Average investment term, alternative investments	10 years
AlternativeFunds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 3,000	$ 2,000
Minimum | AlternativeFunds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	5 years
Maximum | AlternativeFunds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	10 years