Long-Term Debt - Summary of Long-Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Long-term debt	$ 1,661,487	$ 1,845,774
Less discounts	(17,948)	(21,800)
Less current maturities	(14,050)	(21,330)
Total long-term debt, net of current maturities	1,629,489	1,802,644
Term Loan A [Member]
Debt Instrument [Line Items]
Long-term debt		152,000
Term Loan B [Member]
Debt Instrument [Line Items]
Long-term debt		1,293,774
Term B-2 Loans [Member]
Debt Instrument [Line Items]
Long-term debt	1,401,487
Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 260,000	$ 400,000