Long-Term Debt - Capped Called Transactions (Details) - USD ($)
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Line of Credit Facility [Line Items]    
Premiums paid on capped call transactions $ 14,688,000 $ 0
Convertible Senior Notes Due 2028 | Convertible Notes Payable    
Line of Credit Facility [Line Items]    
Debt instrument conversion strike price $ 6.28  
Debt instrument conversion cap price $ 8.4525  
Premiums paid on capped call transactions $ 14,700,000