v3.20.4
Debt - 2025 Notes - Additional Information (Detail) - 5.30% Senior Notes due in 2025 ("2025 Notes") [Member]
$ in Millions
1 Months Ended
Aug. 31, 2017
USD ($)
Debt Instrument [Line Items]  
Principal amount of convertible senior notes $ 1,800
Proceeds from convertible senior notes, net of underwriting discounts and issuance costs $ 1,770