Employee Benefit Plans Employee Benefit Plans (Obligations, Funded Status, and Periodic Benefit Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	$ 12,182	$ 12,873	$ 11,950
Estimated fair value of plan assets	10,971	11,256	10,230
Over (under) funded status	(1,211)	(1,617)
Net periodic benefit costs	194	246	336
Pension Benefits | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	11,086	11,700
Estimated fair value of plan assets	10,392	10,692
Over (under) funded status	(694)	(1,008)
Net periodic benefit costs	97	143
Pension Benefits | Non- U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	1,096	1,173
Estimated fair value of plan assets	579	564
Over (under) funded status	(517)	(609)
Net periodic benefit costs	97	103
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	1,138	1,252	1,289
Estimated fair value of plan assets	1,443	1,492	1,468
Over (under) funded status	305	240
Net periodic benefit costs	(53)	(92)	$ (67)
Other Postretirement Benefits | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	1,099	1,208
Estimated fair value of plan assets	1,417	1,465
Over (under) funded status	318	257
Net periodic benefit costs	(55)	(94)
Other Postretirement Benefits | Non- U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	39	44
Estimated fair value of plan assets	26	27
Over (under) funded status	(13)	(17)
Net periodic benefit costs	$ 2	$ 2