Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Schedule of Long-Term Debt (Parenthetical) (Detail)

v3.19.2
Long-Term Debt - Schedule of Long-Term Debt (Parenthetical) (Detail)
1 Months Ended 6 Months Ended
Aug. 31, 2018
Mar. 31, 2018
Feb. 28, 2014
Jun. 30, 2019
2.00% Convertible Senior Notes Due 2019 [Member]        
Debt Instrument [Line Items]        
Debt instrument interest rate     2.00% 2.00%
Debt instrument maturity date     Aug. 15, 2019 Aug. 15, 2019
2.625% Convertible Senior Notes Due 2024 [Member]        
Debt Instrument [Line Items]        
Debt instrument interest rate   2.625%   2.625%
Debt instrument maturity date   Mar. 15, 2024   Mar. 15, 2024
7.250% Senior Notes Due 2026 [Member]        
Debt Instrument [Line Items]        
Debt instrument interest rate 7.25%     7.25%
Debt instrument maturity date Aug. 15, 2026     Aug. 15, 2026