v3.19.3.a.u2
Fair Value of Financial Instruments - Additional Information (Detail) - Recourse debt [Member]
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
1.25% Convertible Senior Notes due in 2021 ("2021 Notes") [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Interest Rate 1.25%  
Maturity Date Mar. 31, 2021  
5.30% Senior Notes due in 2025 ("2025 Notes") [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Interest Rate 5.30% 5.30%
Maturity Date Aug. 31, 2025 Aug. 31, 2025
2.375% Convertible Senior Notes due in 2022 ("2022 Notes") [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Interest Rate 2.375%  
Maturity Date Mar. 31, 2022  
2.00% Convertible Senior Notes due in 2024 ("2024 Notes") [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Interest Rate 2.00%  
Maturity Date May 31, 2024  
Zero Coupon Convertible Senior Notes due in 2020 ("2020 Notes") [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Interest Rate 0.00% 0.00%
Maturity Date Dec. 31, 2020