Derivative Financial Instruments and Hedging Activities (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Derivative [Line Items]
Debt Carrying Value Fair Value	$ 31,200,000,000		$ 31,200,000,000		$ 37,500,000,000
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(283,000,000)	$ (29,000,000)	(562,000,000)	$ (86,000,000)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	1,165,000,000		1,165,000,000		1,065,000,000
Fair Value of Derivative Liabilities	3,628,000,000		3,628,000,000		512,000,000
Derivative, Notional Amount	81,966,000,000		81,966,000,000		85,778,000,000
Derivative, Collateral, Obligation to Return Cash	225,000,000		225,000,000		26,000,000
Derivative, Collateral, Right to Reclaim Cash	182,000,000		182,000,000		71,000,000
Derivative Asset, Not Offset, Policy Election Deduction	225,000,000		225,000,000		415,000,000
Derivative Liability, Not Offset, Policy Election Deduction	225,000,000		225,000,000		415,000,000
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	(39,000,000)	98,000,000	62,000,000	299,000,000
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	(600,000,000)	(142,000,000)	(1,922,000,000)	(680,000,000)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	615,000,000	135,000,000	1,991,000,000	638,000,000
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	19,159,000,000		19,159,000,000		23,893,000,000
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	(8,000,000)	(2,000,000)	(17,000,000)	(6,000,000)
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	(66,000,000)	(28,000,000)	(164,000,000)	(67,000,000)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	67,000,000	25,000,000	173,000,000	58,000,000
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	885,000,000		885,000,000		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	0		0		544,000,000
Fair Value of Derivative Liabilities	1,645,000,000		1,645,000,000		274,000,000
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	0		0		0
Fair Value of Derivative Liabilities	220,000,000		220,000,000		49,000,000
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	130,000,000	0	342,000,000	(25,000,000)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	50,195,000,000		50,195,000,000		50,060,000,000
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	946,000,000		946,000,000		338,000,000
Fair Value of Derivative Liabilities	572,000,000		572,000,000		126,000,000
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	112,000,000	79,000,000	137,000,000	87,000,000
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	5,144,000,000		5,144,000,000		4,407,000,000
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	209,000,000		209,000,000		66,000,000
Fair Value of Derivative Liabilities	83,000,000		83,000,000		2,000,000
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	(494,000,000)	$ (194,000,000)	(1,164,000,000)	$ (390,000,000)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Derivative, Notional Amount	6,583,000,000		6,583,000,000		6,533,000,000
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	10,000,000		10,000,000		117,000,000
Fair Value of Derivative Liabilities	$ 1,108,000,000		$ 1,108,000,000		$ 61,000,000