Supplemental Cash Flow Information (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Supplemental Cash Flow [Line Items]    
Capital expenditures included in current liabilities $ 98.8 $ 58.9
Cash paid for interest, net of interest capitalized amounts 15.6 0.3
Cash paid for income taxes $ 0 $ 20.6