Quarterly report pursuant to Section 13 or 15(d)

Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details)

v3.20.4
Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Jun. 30, 2020
Dec. 31, 2019
Dec. 31, 2019
Dec. 31, 2020
Sep. 30, 2020
Apr. 01, 2020
Mar. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Recognition of total right-of-use assets       $ 43,530      
Total operating lease liabilities       48,197      
Shareholders' equity       1,059,742 $ 1,022,912   $ 961,497
Derecognized deferred rent   $ (3,500) $ (10,200)        
Cumulative Effect, Period of Adoption, Adjustment              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Shareholders' equity             306
Accumulated Deficit              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Shareholders' equity       $ (544,960) $ (563,376)   (594,026)
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Shareholders' equity             $ 306
Accounting Standards Update 2016-02              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Recognition of total right-of-use assets           $ 50,600  
Total operating lease liabilities           50,700  
Derecognized deferred rent $ 3,300            
Accounting Standards Update 2016-02 | Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Shareholders' equity           $ 300