Long-Term Debt - Summary of Long-Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt	$ 1,615,950	$ 1,657,975
Long-term debt	1,615,950	1,657,975
Less discounts	(9,531)	(11,394)
Less current maturities	(14,050)	(14,050)
Total long-term debt, net of current maturities	1,592,369	1,632,531
Revolving Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term debt
Long-term debt
Term B-2 Loans [Member]
Debt Instrument [Line Items]
Long-term debt	1,355,950	1,397,975
Long-term debt	1,355,950	1,397,975
Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt	260,000	260,000
Long-term debt	$ 260,000	$ 260,000