Employee Benefit Plans Employee Benefit Plans (Obligations, Funded Status, and Periodic Benefit Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	$ 9,498	$ 9,298	$ 12,182
Estimated fair value of plan assets	8,270	8,294	10,971
Over (under) funded status	(1,228)	(1,004)
Net periodic benefit costs	291	122	194
Pension Benefits | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	8,649	8,425
Estimated fair value of plan assets	7,786	7,831
Over (under) funded status	(863)	(594)
Net periodic benefit costs	227	49
Pension Benefits | Non- U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	849	873
Estimated fair value of plan assets	484	463
Over (under) funded status	(365)	(410)
Net periodic benefit costs	64	73
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	765	794	1,138
Estimated fair value of plan assets	1,334	1,303	1,443
Over (under) funded status	569	509
Net periodic benefit costs	(38)	(42)	$ (53)
Other Postretirement Benefits | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	723	758
Estimated fair value of plan assets	1,307	1,277
Over (under) funded status	584	519
Net periodic benefit costs	(41)	(43)
Other Postretirement Benefits | Non- U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	42	36
Estimated fair value of plan assets	27	26
Over (under) funded status	(15)	(10)
Net periodic benefit costs	$ 3	$ 1