Other Comprehensive Income (Loss) - Changes in AOCI Balance by Component (Details) - USD ($) $ in Millions	3 Months Ended								6 Months Ended
	Jun. 30, 2022		Mar. 31, 2022		Jun. 30, 2021		Mar. 31, 2021		Jun. 30, 2022
Other Comprehensive Income (Loss)
Income Before Reclassifications									$ 71
Amounts Reclassified to Net Earnings									18
Tax (Expense)/Benefit									(19)
Total Other Comprehensive Income	$ 39		$ 31		$ (21)		$ 68		70
Pension and Other Post-Employment Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance December 31, 2021, Net of Tax			(431)						(431)
Other Comprehensive Income (Loss)
Income Before Reclassifications									0
Amounts Reclassified to Net Earnings									21
Tax (Expense)/Benefit									(5)
Total Other Comprehensive Income									16
Balance June 30, 2022, Net of Tax	(415)								(415)
Interest Rate Derivatives
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance December 31, 2021, Net of Tax			70						70
Other Comprehensive Income (Loss)
Income Before Reclassifications									71
Amounts Reclassified to Net Earnings									0
Tax (Expense)/Benefit									(17)
Total Other Comprehensive Income									54
Balance June 30, 2022, Net of Tax	124								124
Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance December 31, 2021, Net of Tax			(47)						(47)
Other Comprehensive Income (Loss)
Income Before Reclassifications									0
Amounts Reclassified to Net Earnings									(3)
Tax (Expense)/Benefit									3
Total Other Comprehensive Income									0
Balance June 30, 2022, Net of Tax	(47)								(47)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance December 31, 2021, Net of Tax			(408)						(408)
Other Comprehensive Income (Loss)
Total Other Comprehensive Income	39	[1]	$ 31	[1]	$ (21)	[2]	$ 68	[2]
Balance June 30, 2022, Net of Tax	$ (338)								$ (338)

[1] Accumulated Other Comprehensive Loss balances shown above are net of tax. The associated taxes were $99 million and $88 million as of first and second quarters 2022, respectively. For additional information, see Note 10, Other Comprehensive Income.

[2] Accumulated Other Comprehensive Loss balances shown above are net of tax. The associated taxes were $137 million and $142 million as of first and second quarters 2021, respectively. For additional information, see Note 10, Other Comprehensive Income.