Debt - Asset-Backed Debt Narrative (Detail)	1 Months Ended				12 Months Ended
	Jan. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) agreement	May 31, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Repayments of debt					$ 9,078,000,000
Asset-Backed Debt
Debt Instrument [Line Items]
Secured debt, carrying value		$ 14,200,000,000			14,200,000,000
Repayments of debt					4,800,000,000	$ 7,400,000,000
Asset Backed Notes
Debt Instrument [Line Items]
Principal amount issued		3,100,000,000			3,100,000,000
2020 ABS Financing Facility
Debt Instrument [Line Items]
Repayments of debt			$ 1,500,000,000
Amount drawn from credit facilities				$ 1,000,000,000
Outstanding balance		0			0
2021 ABS Financing Facility
Debt Instrument [Line Items]
Amount drawn from credit facilities		4,300,000,000
Outstanding balance		$ 4,300,000,000			4,300,000,000
Number of loan agreements | agreement		2
2021 ABS Financing Facility | Minimum
Debt Instrument [Line Items]
Debt revolving period		1 year
2021 ABS Financing Facility | Maximum
Debt Instrument [Line Items]
Debt revolving period		2 years
Senior asset-backed notes | Asset Backed Notes
Debt Instrument [Line Items]
Repayments of debt					$ 3,300,000,000	$ 3,400,000,000
Senior asset-backed notes | Asset Backed Notes | Minimum
Debt Instrument [Line Items]
Debt revolving period					2 years
Senior asset-backed notes | Asset Backed Notes | Maximum
Debt Instrument [Line Items]
Debt revolving period					3 years
Subsequent event | Asset Backed Notes
Debt Instrument [Line Items]
Repayments of debt	$ 179,000,000
Principal amount issued	1,700,000,000
Subsequent event | 2021 ABS Financing Facility
Debt Instrument [Line Items]
Repayments of debt	$ 515,000,000