Long Term Obligation - Additional Information (Detail) (Senior Secured Term Loan Facility, due 2018 [Member], USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Debt Instrument [Line Items]
Amended and Restated senior secured term loans	$ 970.0
Repayment of New term loan	$ 448.4
Soft call option	1.00%
Libor Rate [Member]
Debt Instrument [Line Items]
Interest rate margin	4.50%
Interest rate floor	1.25%
Base Rate [Member]
Debt Instrument [Line Items]
Interest rate margin	3.50%
Interest rate floor	2.25%