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Long-Term Debt - Senior Notes (Details)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
tranch
Debt Instrument      
Debt instrument face amount     $ 800,000,000.0
Number of tranches (tranche) | tranch     2
Unamortized debt issuance costs $ 10,774,000 $ 11,417,000  
Senior Note Maturing December 2025      
Debt Instrument      
Debt instrument face amount     $ 400,000,000.0
Debt instrument stated interest rate (percent)     4.63%
Senior Note Maturing December 2027      
Debt Instrument      
Debt instrument face amount     $ 400,000,000.0
Senior notes | Senior Note Maturing December 2027      
Debt Instrument      
Debt instrument stated interest rate (percent)     4.88%