Other Comprehensive Income (Loss) - Changes in AOCI Balance by Component (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Other Comprehensive Income (Loss)
Income Before Reclassifications		$ 28
Amounts Reclassified to Net Earnings		11
Tax (Expense)/Benefit		(8)
Total Other Comprehensive Income		31	$ 68
Pension and Other Post-Employment Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance December 31, 2021, Net of Tax		(431)
Other Comprehensive Income (Loss)
Income Before Reclassifications		0
Amounts Reclassified to Net Earnings		11
Tax (Expense)/Benefit		(3)
Total Other Comprehensive Income		8
Balance March 31, 2022, Net of Tax		(423)
Interest Rate Derivatives
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance December 31, 2021, Net of Tax		70
Other Comprehensive Income (Loss)
Income Before Reclassifications		28
Amounts Reclassified to Net Earnings		0
Tax (Expense)/Benefit		(7)
Total Other Comprehensive Income		21
Balance March 31, 2022, Net of Tax		91
Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance December 31, 2021, Net of Tax		(47)
Other Comprehensive Income (Loss)
Income Before Reclassifications		0
Amounts Reclassified to Net Earnings		0
Tax (Expense)/Benefit		2
Total Other Comprehensive Income		2
Balance March 31, 2022, Net of Tax		(45)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance December 31, 2021, Net of Tax		(408)
Other Comprehensive Income (Loss)
Total Other Comprehensive Income	[1]	31	$ 68
Balance March 31, 2022, Net of Tax		$ (377)

[1] (a) Accumulated Other Comprehensive Loss balances shown above are net of tax. The associated taxes were $99 million and $137 million as of March 31, 2022 and March 31, 2021, respectively. For additional information, see Note 11, Other Comprehensive Income.