Accumulated Other Comprehensive Loss (Summary of Changes in AOCI) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (2,115)	$ (3,921)	$ (1,915)	$ (3,734)
Other comprehensive (loss) income before reclassifications, net - Foreign Currency Translation	(242)	(176)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax	(11)	(10)
Other comprehensive (loss) income before reclassifications, net - Unrealized Hedging Gains (Losses)	31	(46)
Other comprehensive (loss) income before reclassifications, net	(222)	(232)
Amounts reclassified, pretax - Foreign Currency Translation	2	0
Amounts reclassified, pretax - Pension	32	64
Amounts reclassified, pretax - Unrealized Hedging Gains (Losses)	6	(14)
Amounts reclassified, pre-tax	40	50
Tax benefit (expense) - Foreign Currency Translation	(3)	(5)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	(4)	(12)
Tax benefit (expense) - Unrealized Hedging Gains (Losses)	(11)	12
Income tax expense related to items of other comprehensive income (loss)	(18)	(5)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(194)	529	49	710
Defined Benefit Pension and Post-retirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(1,811)	(4,441)	(1,828)	(4,483)
Unrealized hedging (losses) gains
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (110)	$ (9)	$ (136)	$ 39