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Long-Term Debt and Letters of Credit - Credit Facility and Capital Lease (Details)
Mar. 31, 2019
USD ($)
Letter of Credit  
Line of Credit Facility [Line Items]  
Letters of credit, outstanding $ 34,700,000
Credit facility | $750.0 million credit facility due March 2024, weighted average rate of 3.45% at March 31, 2019 and 5.50% at December 30, 2018  
Line of Credit Facility [Line Items]  
Maximum borrowing capacity 750,000,000
Credit facility | Letter of Credit  
Line of Credit Facility [Line Items]  
Available borrowings capacity under letters of credit $ 571,200,000