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Debt - Convertible Senior Notes, Additional Information (Details)
3 Months Ended
Dec. 31, 2019
USD ($)
Mar. 31, 2020
USD ($)
d
$ / shares
Mar. 31, 2019
USD ($)
Mar. 31, 2015
USD ($)
Dec. 31, 2015
USD ($)
Debt Instrument [Line Items]          
If-converted amount exceed principal $ 600,000        
Interest expense, debt   $ 200,000 $ 1,000,000.0    
Convertible Senior Notes          
Debt Instrument [Line Items]          
Face amount         $ 172,500,000
Convertible Senior Notes | 3.25% Convertible Senior Notes due 2020          
Debt Instrument [Line Items]          
Debt issuance cost         5,100,000
Deferred financing costs         $ 4,200,000
Debt instrument, term       6 years  
Adjustments to additional paid in capital       $ 900,000  
Effective interest rate         6.90%
Conversion ratio   31.1891      
Conversion price (in usd per share) | $ / shares   $ 32.06      
Number of threshold trading days | d   20      
Number of threshold consecutive trading days | d   30      
Threshold percentage of stock price trigger   130.00%      
Threshold consecutive trading days | d   5      
Threshold percentage of stock price trigger   98.00%      
Amortization of debt discount (premium)   $ 100,000 500,000    
Interest expense   $ 100,000 $ 500,000    
Convertible Senior Notes | Convertible Senior Notes | 3.25% Convertible Senior Notes due 2020          
Debt Instrument [Line Items]          
Stated interest rate   3.25%