Quarterly report pursuant to Section 13 or 15(d)

Debt - Lines of Credit and Other Debt Facilities (Details)

v3.19.1
Debt - Lines of Credit and Other Debt Facilities (Details) - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Debt Instrument    
Debt and capital lease obligations $ 1,644,500,000 $ 5,376,000,000.0
Revolving Credit Facility    
Debt Instrument    
Reduction in borrowings 5,100,000 9,700,000
Line of Credit    
Debt Instrument    
Debt and capital lease obligations 200,000 0
Outstanding letters of credit 5,400,000 10,200,000
Line of Credit | Revolving Credit Facility    
Debt Instrument    
Debt and capital lease obligations 120,000,000.0 25,000,000.0
Line of Credit | Lines of Credit and Revolving Lines of Credit    
Debt Instrument    
Debt and capital lease obligations 120,000,000 25,000,000.0
Remaining borrowing capacity $ 232,000,000 $ 481,000,000