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Credit Facility (Details) - Line of credit - USD ($)
1 Months Ended
Dec. 31, 2018
Dec. 31, 2019
Prior Credit Agreement    
Debt Instrument [Line Items]    
Borrowings outstanding $ 0  
Senior unsecured revolving credit facility    
Debt Instrument [Line Items]    
Maximum borrowing capacity $ 750,000,000.0  
Line of credit facility, expiration period 5 years  
Borrowings outstanding   $ 0
Increase Limit $ 250,000,000.0  
Letters of credit    
Debt Instrument [Line Items]    
Maximum borrowing capacity $ 50,000,000.0