Fair Value of Financial Instruments - Schedule of Estimated Fair Values and Carrying Values (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	$ 9,479	$ 10,402
Convertible Senior Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	3,734	3,686
Fair Value	7,375	6,067
5.30% Senior Notes due in 2025 ("2025 Notes") [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	1,783	1,782
Fair Value	1,688	1,748
Solar asset-backed notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	1,139	1,155
Fair Value	969	1,211
Solar Loan-backed Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	161	175
Fair Value	$ 136	$ 189