Derivative Financial Instruments and Hedging Activities (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Derivative [Line Items]
Debt Carrying Value Fair Value	$ 36,500,000,000		$ 33,300,000,000
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(129,000,000)	$ (24,000,000)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	817,000,000		987,000,000
Fair Value of Derivative Liabilities	2,436,000,000		3,026,000,000
Derivative, Notional Amount	88,860,000,000		91,832,000,000
Derivative, Collateral, Obligation to Return Cash	180,000,000		210,000,000
Derivative, Collateral, Right to Reclaim Cash	172,000,000		193,000,000
Derivative Asset, Not Offset, Policy Election Deduction	211,000,000		166,000,000
Derivative Liability, Not Offset, Policy Election Deduction	211,000,000		166,000,000
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Net interest settlements and accruals excluded from the assessment of hedge effectiveness	(140,000,000)	76,000,000
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	250,000,000	(986,000,000)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	(279,000,000)	991,000,000
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	19,042,000,000		16,883,000,000
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Currency Swap
Income Effect of Derivative Financial Instruments [Abstract]
Net interest settlements and accruals excluded from the assessment of hedge effectiveness	(14,000,000)	(3,000,000)
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	22,000,000	(37,000,000)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	(19,000,000)	41,000,000
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	1,421,000,000		885,000,000
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Level 2 [Member] | Fair Value, Recurring [Member] | Fair Value Hedging [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	15,000,000		0
Fair Value of Derivative Liabilities	1,302,000,000		1,653,000,000
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Level 2 [Member] | Fair Value, Recurring [Member] | Currency Swap
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	4,000,000		0
Fair Value of Derivative Liabilities	135,000,000		161,000,000
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(12,000,000)	123,000,000
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	57,312,000,000		63,210,000,000
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Level 2 [Member] | Fair Value, Recurring [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	753,000,000		931,000,000
Fair Value of Derivative Liabilities	397,000,000		483,000,000
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(22,000,000)	(2,000,000)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	4,970,000,000		4,219,000,000
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Level 2 [Member] | Fair Value, Recurring [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	7,000,000		41,000,000
Fair Value of Derivative Liabilities	74,000,000		76,000,000
Cross Currency Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	85,000,000	$ (227,000,000)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	6,115,000,000		6,635,000,000
Cross Currency Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Level 2 [Member] | Fair Value, Recurring [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	38,000,000		15,000,000
Fair Value of Derivative Liabilities	$ 528,000,000		$ 653,000,000