Debt (Details 3) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Interest Expense, net    
Interest $ 13.0 $ 13.1
Accretion of debt discount, deferred financing amortization and line of credit fees 1.8 1.8
Capitalized interest (2.1) (14.8)
Interest expense 12.7 0.1
Interest income   (0.1)
Interest expense, net $ 12.7