Annual report pursuant to Section 13 and 15(d)

Debt - Additional Information (Details)

v3.19.3.a.u2
Debt - Additional Information (Details)
12 Months Ended
Apr. 02, 2018
USD ($)
Instrument
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Debt Instrument [Line Items]      
Available credit under agreement $ 500,000,000.0    
Credit facility maximum borrowing capacity under accordion feature 200,000,000.0    
Letter of credit, sub-limit amount $ 50,000,000.0    
Interest rate percentage   3.71%  
Line of credit facility drawn   $ 253,000,000 $ 235,000,000.0
Letter of credit outstanding   $ 28,400,000 $ 30,400,000
Minimum      
Debt Instrument [Line Items]      
Commitment fee rates for unused commitments 0.20%    
Maximum      
Debt Instrument [Line Items]      
Commitment fee rates for unused commitments 0.35%    
Federal Funds Rate      
Debt Instrument [Line Items]      
Line of credit facility interest rate 0.50%    
Eurodollar      
Debt Instrument [Line Items]      
Line of credit facility interest rate 1.50% 3.56%  
Line of credit facility, borrowing outstanding | Instrument 15    
Eurodollar | Minimum      
Debt Instrument [Line Items]      
Line of credit facility interest rate 1.50%    
Eurodollar | Maximum      
Debt Instrument [Line Items]      
Line of credit facility interest rate 2.25%    
Base rate      
Debt Instrument [Line Items]      
Line of credit facility interest rate   5.50%  
Base rate | Minimum      
Debt Instrument [Line Items]      
Line of credit facility interest rate 0.50%    
Base rate | Maximum      
Debt Instrument [Line Items]      
Line of credit facility interest rate 1.25%