Debt - Summary of Debt and Finance Leases (Detail) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2021	Dec. 31, 2020	Jan. 01, 2021
Debt Instrument [Line Items]
Net Carrying Value, Current		$ 1,082	$ 1,758
Net Carrying Value, Long-Term		6,878	8,462
Unpaid Principal Balance		8,029	10,569
Unused Committed Amount	[1]	1,576	2,632
Net Carrying Value Finance leases, Current		448	374
Net Carrying Value Finance leases, Long-Term		993	1,094
Current portion of debt and finance leases		1,530	2,132	$ 2,182
Net Carrying Value Total debt and finance leases, Long-Term		7,871	9,556	$ 9,775
5.30% Senior Notes due in 2025 (2025 Notes) [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long-Term		1,787	1,785
Solar Asset-backed Notes [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long-Term		1,095	1,115
Solar Loan-backed Notes [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long-Term		128	146
Recourse debt [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		139	709
Net Carrying Value, Long-Term		3,838	4,951
Unpaid Principal Balance		3,992	5,957
Unused Committed Amount	[1]	280	278
Recourse debt [Member] | 2.375% Convertible Senior Notes due in 2022 [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		130	115
Net Carrying Value, Long-Term			366
Unpaid Principal Balance		$ 131	$ 503
Debt Instrument Interest Rate Stated Percentage		2.375%	2.375%
Contractual Maturity Date		2022-03	2022-03
Recourse debt [Member] | 2.00% Convertible Senior Notes due in 2024 [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		$ 7	$ 171
Net Carrying Value, Long-Term		166	856
Unpaid Principal Balance		$ 174	$ 1,282
Debt Instrument Interest Rate Stated Percentage		2.00%	2.00%
Contractual Maturity Date		2024-05	2024-05
Net Carrying Value Total debt and finance leases, Long-Term		$ 7
Recourse debt [Member] | 5.30% Senior Notes due in 2025 (2025 Notes) [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long-Term		1,787	$ 1,785
Unpaid Principal Balance		$ 1,800	$ 1,800
Debt Instrument Interest Rate Stated Percentage		5.30%	5.30%
Contractual Maturity Date		2025-08	2025-08
Recourse debt [Member] | 1.25% Convertible Senior Notes due in 2021 (2021 Notes) [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current			$ 419
Unpaid Principal Balance			$ 422
Debt Instrument Interest Rate Stated Percentage		1.25%	1.25%
Contractual Maturity Date			2021-03
Recourse debt [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long-Term		$ 1,878	$ 1,895
Unpaid Principal Balance		1,878	1,895
Unused Committed Amount	[1]	$ 280	$ 278
Debt Instrument Interest Rate Stated Percentage		3.30%	3.30%
Contractual Maturity Date		2023-07	2023-07
Recourse debt [Member] | Solar Bonds and other Loans [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		$ 2	$ 4
Net Carrying Value, Long-Term		7	49
Unpaid Principal Balance		$ 9	$ 55
Contractual Maturity Date, Start		2021-10	2021-01
Contractual Maturity Date, End		2031-01	2031-01
Recourse debt [Member] | Solar Bonds and other Loans [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		4.00%	3.60%
Recourse debt [Member] | Solar Bonds and other Loans [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		5.80%	5.80%
Non-recourse debt [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		$ 943	$ 1,049
Net Carrying Value, Long-Term		3,040	3,511
Unpaid Principal Balance		4,037	4,612
Unused Committed Amount	[1]	1,296	2,354
Non-recourse debt [Member] | Automotive Asset-backed Notes [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		869	777
Net Carrying Value, Long-Term		1,455	921
Unpaid Principal Balance		$ 2,333	1,705
Unused Committed Amount	[1]		$ 153
Contractual Maturity Date, Start		2021-08	2021-08
Contractual Maturity Date, End		2025-03	2024-08
Non-recourse debt [Member] | Automotive Asset-backed Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		0.20%	0.60%
Non-recourse debt [Member] | Automotive Asset-backed Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		7.90%	7.90%
Non-recourse debt [Member] | Solar Asset-backed Notes [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		$ 41	$ 39
Net Carrying Value, Long-Term		1,054	1,076
Unpaid Principal Balance		$ 1,122	$ 1,141
Contractual Maturity Date, Start		2024-09	2024-09
Contractual Maturity Date, End		2048-02	2048-02
Non-recourse debt [Member] | Solar Asset-backed Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		2.90%	3.00%
Non-recourse debt [Member] | Solar Asset-backed Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		7.70%	7.70%
Non-recourse debt [Member] | China Loan Agreements [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long-Term			$ 616
Unpaid Principal Balance			616
Unused Committed Amount	[1]		$ 1,372
Debt Instrument Interest Rate Stated Percentage			4.00%
Contractual Maturity Date, Start			2021-06
Contractual Maturity Date, End			2024-12
Non-recourse debt [Member] | Cash Equity Debt [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		$ 20	$ 18
Net Carrying Value, Long-Term		402	408
Unpaid Principal Balance		$ 434	$ 439
Contractual Maturity Date, Start		2033-07	2033-07
Contractual Maturity Date, End		2035-01	2035-01
Non-recourse debt [Member] | Cash Equity Debt [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		5.30%	5.30%
Non-recourse debt [Member] | Cash Equity Debt [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		5.80%	5.80%
Non-recourse debt [Member] | Solar Loan-backed Notes [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current		$ 13
Net Carrying Value, Long-Term		115	$ 133
Unpaid Principal Balance		$ 134	$ 152
Debt Instrument Interest Rate Stated Percentage			13.00%
Contractual Maturity Date, Start		2048-09	2048-09
Contractual Maturity Date, End		2049-09	2049-09
Non-recourse debt [Member] | Solar Loan-backed Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		4.80%	4.80%
Non-recourse debt [Member] | Solar Loan-backed Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage		7.50%	7.50%
Non-recourse debt [Member] | Warehouse Agreements [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current			$ 37
Net Carrying Value, Long-Term			257
Unpaid Principal Balance			294
Unused Committed Amount	[1]	$ 1,100	$ 806
Contractual Maturity Date		2022-09	2022-09
Non-recourse debt [Member] | Warehouse Agreements [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage			1.70%
Non-recourse debt [Member] | Warehouse Agreements [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage			1.80%
Non-recourse debt [Member] | Automotive Lease-backed Credit Facilities [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current			$ 14
Net Carrying Value, Long-Term			19
Unpaid Principal Balance			$ 33
Unused Committed Amount	[1]	$ 173
Contractual Maturity Date		2022-09
Contractual Maturity Date, Start			2022-09
Contractual Maturity Date, End			2022-11
Non-recourse debt [Member] | Automotive Lease-backed Credit Facilities [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage			1.90%
Non-recourse debt [Member] | Automotive Lease-backed Credit Facilities [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage			5.90%
Non-recourse debt [Member] | Solar Revolving Credit Facility and Other Loans [Member]
Debt Instrument [Line Items]
Net Carrying Value, Long-Term		$ 14	$ 81
Unpaid Principal Balance		14	81
Unused Committed Amount	[1]	$ 23	$ 23
Debt Instrument Interest Rate Stated Percentage		5.10%
Contractual Maturity Date		2033-02
Contractual Maturity Date, Start			2022-06
Contractual Maturity Date, End			2033-02
Non-recourse debt [Member] | Solar Revolving Credit Facility and Other Loans [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage			2.70%
Non-recourse debt [Member] | Solar Revolving Credit Facility and Other Loans [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage			5.10%
Non-recourse debt [Member] | Solar Term Loans [Member]
Debt Instrument [Line Items]
Net Carrying Value, Current			$ 151
Unpaid Principal Balance			$ 151
Debt Instrument Interest Rate Stated Percentage			3.70%
Contractual Maturity Date			2021-01

[1] There are no restrictions on draw-down or use for general corporate purposes with respect to any available committed funds under our credit facilities and financing funds, except certain specified conditions prior to draw-down, including pledging to our lenders sufficient amounts of qualified receivables, inventories, leased vehicles and our interests in those leases, solar energy systems and the associated customer contracts, our interests in financing funds or various other assets and as may be described below and in the notes to the consolidated financial statements included in our report on Form 10-K for the year ended December 31, 2020.