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
	Mar. 31, 2013	Mar. 31, 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
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 )	3.9	7.1
Amount of (Gain) or Loss Recognized in Net Loss (Ineffective Portion)	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	$ (21.0)	$ 34.7