Basic and Diluted Net Loss Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net loss
Net loss	$ (678.2)	$ (69.8)	$ (866.8)	$ (187.2)
Basic and diluted net loss per share:
Basic	$ (7.88)	$ (0.82)	$ (10.10)	$ (2.22)
Diluted	$ (7.88)	$ (0.82)	$ (10.10)	$ (2.22)
Weighted average number of shares used in per share calculations:
Basic shares	86.1	84.7	85.8	84.5
Diluted shares	86.1	84.7	85.8	84.5