Fair Value of Financial Instruments - Schedule of Estimated Fair Values and Carrying Values (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	$ 5,439	$ 8,462
Convertible Senior Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	228	1,971
Fair Value	2,814	24,596
2025 Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	0	1,785
Fair Value	0	1,877
Solar Asset-backed Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	1,080	1,115
Fair Value	1,101	1,137
Solar Loan-backed Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	108	146
Fair Value	$ 115	$ 152