Long-Term Debt - Additional Information (Detail) (USD $)	12 Months Ended				1 Months Ended			1 Months Ended	12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 16, 2011	May 13, 2011	Dec. 20, 2012 Before Amendment	Dec. 20, 2012 After Amendment	Dec. 08, 2011 Interest Rate Cap	Dec. 08, 2011 Interest Rate Cap J P Morgan	Dec. 31, 2012 Second Lien Facility	Sep. 16, 2011 Second Lien Facility	Dec. 31, 2012 Revolving Credit Facility	Sep. 16, 2011 Revolving Credit Facility	Dec. 31, 2012 First Lien Facility	Sep. 16, 2011 First Lien Facility	Dec. 20, 2012 LIBOR Before Amendment	Dec. 20, 2012 LIBOR After Amendment	Dec. 20, 2012 Base Rate Before Amendment	Dec. 20, 2012 Base Rate After Amendment
Line of Credit Facility [Line Items]
Total credit facility										$ 790,000,000		$ 300,000,000		$ 1,325,000,000
Term loan discount										12,000,000				13,500,000
Letters of credit drawn			30,000,000
Swingline borrowings			30,000,000
Basis spread on LIBOR/base rate															4.50%	3.50%	3.50%	2.50%
LIBOR floor					1.25%	1.00%			1.50%		1.00%		1.00%
Write off of deferred financing costs	2,400,000
Deferred financing capitalized costs	800,000
Interest on LIBOR-based borrowings									LIBOR plus 6.0 %				LIBOR plus 3.5 %
Interest on Base Rate-based borrowings													2.50%
Base Rate Floor									2.50%		2.00%		2.25%
Federal Funds Rate									1.00%		1.00%		1.00%
Federal Funds Rate									Federal Reserve Bank Rate plus 1/2 of 1.0%		Federal Reserve Bank Rate plus 1/2 of 1.0%		Federal Reserve Bank Rate plus 1/2 of 1.0%
Base Rate									1.00%		1.00%		1.00%
Base Rate									30 day LIBOR plus 1.0%		30 day LIBOR plus 1.0%		30 day LIBOR plus 1.0%
Amortization rate per annum	1.00%
Interest on Base Rate-based borrowings on Second Lien Facility									Base Rate plus 5.0 %
Amount outstanding									790,000,000				1,300,000,000
Interest on borrowings, per annum									7.50%				4.50%
Interest rate cap aggregate notional amount							71,300,000	71,300,000
LIBOR-based variable interest rate component of long-term debt								3.00%
Swap agreement, Date of maturity								Dec. 08, 2015
Consolidated net leverage ratio													6.5
Prepayment of excess cash flow													63,200,000
Period of repayment of excess cash flow after filing date													10 days
Security interest granted													66.00%
Senior Notes issued				610,000,000
Amount repaid under outstanding term loan facility	575,800,000
Agreement maturity date	May 01, 2019
Percentage of Senior Notes to be redeemed prior to May 1, 2014	35.00%
Percentage of Senior Notes to be redeemed prior to May 1, 2015	100.00%
Amortization of debt discount and debt issuance costs	$ 10,100,000	$ 4,400,000