Long-Term Debt and Other Borrowing Arrangements - Carrying Values of Long-Term Debt and Other Borrowing Arrangements (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Senior subordinated notes	$ 1,521,547us-gaap_SubordinatedLongTermDebt	$ 1,118,261us-gaap_SubordinatedLongTermDebt
Total	1,767,922us-gaap_LongTermDebt	1,367,036us-gaap_LongTermDebt
Less current maturities of Term Loan	(2,500)us-gaap_LongTermDebtCurrent	(2,500)us-gaap_LongTermDebtCurrent
Long-term debt	1,765,422us-gaap_LongTermDebtNoncurrent	1,364,536us-gaap_LongTermDebtNoncurrent
Revolving Credit Agreement Mature 2018 [Member]
Debt Instrument [Line Items]
Revolving credit agreement	0	0
Variable Term loan Due 2020 [Member]
Debt Instrument [Line Items]
Long term debt	246,375	248,775
5.25% Senior Subordinated Notes Due 2024 [Member]
Debt Instrument [Line Items]
Senior subordinated notes	200,000
5.50% Senior subordinated notes due 2023 [Member]
Debt Instrument [Line Items]
Senior subordinated notes	616,326	413,040
5.50% Senior subordinated notes due 2022 [Member]
Debt Instrument [Line Items]
Senior subordinated notes	700,000	700,000
9.25% Senior Subordinated Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior subordinated notes	$ 5,221	$ 5,221

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets.

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Carrying value as of the balance sheet date of collateralized/uncollateralized debt obligation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Subordinated debt places a lender in a lien position behind the primary lender of the company.

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