Derivative Instruments - Effect of Derivative Instruments in Consolidated Statements of Comprehensive Loss (Detail) (Interest rate contracts [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivatives designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in AOCL (Effective Portion)	$ 0	$ 0	$ 0	$ 0
Derivatives designated as hedging instruments [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Reclassified from AOCL into Net Loss (Effective Portion )	0	7.2	3.9	14.3
Amount of (Gain) or Loss Recognized in Net Loss (Ineffective Portion)	0	0	0	0
Derivatives not designated as hedging instruments [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in Net Loss	$ (45.5)	$ (17.6)	$ (66.5)	$ 17.1