Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements and Derivatives (Detail Textuals)

v3.19.2
Fair Value Measurements and Derivatives (Detail Textuals)
kT in Thousands, MT in Millions, $ in Millions, € in Billions
6 Months Ended
Jun. 30, 2019
USD ($)
kT
MT
Jun. 30, 2019
EUR (€)
kT
MT
Dec. 31, 2018
USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair value of long-term debt $ 6,471.1   $ 6,601.9
Fair value of long-term debt in excess of carrying value $ 16.7   $ 8.4
Fuel swaps      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Derivative maturing date Dec. 31, 2022    
Projected fuel purchases | MT 1.3 1.3  
Fuel swaps | Derivative Contracts Not Designated as Hedging Instruments      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Derivative maturing date Dec. 31, 2019    
Projected fuel purchases | kT 19 19  
Foreign currency contracts      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Notional amount of derivatives $ 2,800.0 € 2.5  
Interest rate contracts      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Notional amount of derivatives $ 1,200.0