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Fair Value Measurement - Additional Information (Details) - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2021
Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Asset transfers Level 1 to Level 2 $ 0 $ 0
Asset transfers Level 2 to Level 1 0 0
Asset transfers into Level 3 0 0
Asset transfers out of Level 3 0 0
Liabilities transfers Level 1 to Level 2 0 0
Liabilities transfers Level 2 to Level 1 0 0
Liability transfers into Level 3 0 0
Liability transfers out of Level 3 0 0
Cash and cash equivalents, fair value 547,859,000 350,846,000
2025 Convertible Senior Notes    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Aggregate principal amount 172,500,000  
Debt instrument, convertible, if-converted value in excess of principal 47,100,000  
2028 Convertible Senior Notes    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Aggregate principal amount 287,500,000  
Recurring | Money Market Funds    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Cash and cash equivalents, fair value $ 204,400,000 $ 200,326,000