Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Summary of Significant Accounting Policies - Derivatives (Details)

v3.19.1
Basis of Presentation and Summary of Significant Accounting Policies - Derivatives (Details) - Convertible Notes - 2019 Convertible Senior Notes
Mar. 31, 2019
yr
$ / shares
Aug. 31, 2014
$ / shares
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Common stock price (USD per share) $ 125.71  
Exercise price, conversion premium and bond hedge (USD per share) $ 75.05 $ 75.05
Risk-free interest rate    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Measurement input (as a percent) 0.0246  
Volatility    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Measurement input (as a percent) 0.35  
Dividend yield    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Measurement input (as a percent) 0  
Annual coupon rate    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Measurement input (as a percent) 0.0075  
Remaining contractual term (in years)    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Measurement input (as a percent) | yr 0.38