Reclassifications From Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 22, 2021
Reclassifications from accumulated other comprehensive (loss) income
Other, net	$ 440	$ 37	$ 648	$ 88
Tax (benefit)	(12)	(82)	(55)	(115)
Reclassifications, after tax	15	(234)	(99)	(772)
Interest expense	25	35	227	70
Disproportionate tax expense	11
5.95 Notes and Debentures Due March 15, 2022
Reclassifications from accumulated other comprehensive (loss) income
Debt instrument stated interest rate					5.95%
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest
Reclassifications from accumulated other comprehensive (loss) income
Defined benefit plan actuarial loss		0	447	0
Reclassification out of Accumulated Other Comprehensive Income
Reclassifications from accumulated other comprehensive (loss) income
Defined benefit plan actuarial loss	447
Tax (benefit)	96
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest
Reclassifications from accumulated other comprehensive (loss) income
Other, net	9	6	16	13
Defined benefit plan actuarial loss	447
Tax (benefit)	98	1	100	3
Reclassifications, after tax	358	5	363	10
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
Reclassifications from accumulated other comprehensive (loss) income
Tax (benefit)	0	0	(5)	0
Reclassifications, after tax	0	(1)	(7)	(1)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest | Interest Rate Swap
Reclassifications from accumulated other comprehensive (loss) income
Interest expense	0	$ 1	$ 2	$ 1
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Foreign Currency Adjustment Attributable to Parent | Hüppe
Reclassifications from accumulated other comprehensive (loss) income
Other, net	(23)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent | Hüppe
Reclassifications from accumulated other comprehensive (loss) income
Other, net	$ (3)