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Debt - Additional Information (Details) - USD ($)
3 Months Ended 12 Months Ended
Feb. 12, 2019
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Line of Credit Facility        
Line of credit maximum borrowing amount   $ 300,000,000   $ 300,000,000
Debt amortization expense   $ 42,000 $ 42,000  
Revolving Credit Facility Due 2024        
Line of Credit Facility        
Line of credit maximum borrowing amount $ 300,000,000      
Line of credit facility contingent increase to maximum borrowing capacity $ 150,000,000      
Commitment fee percentage per annum   0.20%   0.23%
Revolving Credit Facility Due 2024 | Minimum        
Line of Credit Facility        
Commitment fee percentage per annum 0.20%      
Revolving Credit Facility Due 2024 | Maximum        
Line of Credit Facility        
Commitment fee percentage per annum 0.30%      
Revolving Credit Facility Due 2024 Swingline Sublimit        
Line of Credit Facility        
Line of credit maximum borrowing amount $ 15,000,000      
Revolving Credit Facility Due 2024 Letter Of Credit Sublimit        
Line of Credit Facility        
Line of credit maximum borrowing amount $ 10,000,000      
Line of Credit | Revolving Credit Facility Due 2024        
Line of Credit Facility        
Debt instrument, term 5 years