Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	$ 64	$ 208
Amounts reclassified from accumulated OCI	(476)	(447)
Net other comprehensive income (loss)	(412)	(239)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	2,766	3,529
Net other comprehensive income (loss)	(412)	(239)
Accumulated other comprehensive income, ending balance	2,354	3,290
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	(1,800)	(1,964)
Other comprehensive income (loss) before reclassifications	193	19
Amounts reclassified from accumulated OCI	0	0
Net other comprehensive income (loss)	193	19
Accumulated other comprehensive income, ending balance	(1,607)	(1,945)
Net Unrealized Gains (Losses) on Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	(90)	45
Other comprehensive income (loss) before reclassifications	23	(69)
Amounts reclassified from accumulated OCI	3	3
Net other comprehensive income (loss)	26	(66)
Accumulated other comprehensive income, ending balance	(64)	(21)
Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	(1,998)	(1,422)
Other comprehensive income (loss) before reclassifications	(152)	258
Amounts reclassified from accumulated OCI	12	15
Net other comprehensive income (loss)	(140)	273
Accumulated other comprehensive income, ending balance	(2,138)	(1,149)
Defined Benefit Postretirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	6,654	6,870
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated OCI	(491)	(465)
Net other comprehensive income (loss)	(491)	(465)
Accumulated other comprehensive income, ending balance	$ 6,163	$ 6,405