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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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The carrying value as of the balance sheet date of the current portion 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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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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Carrying value as of the balance sheet date of the portion of long-term notes having the highest claim on the assets of the issuer in case of bankruptcy or liquidation, due within one year or the normal operating cycle, if longer. Senior note holders are paid off in full before any payments are made to debt holders having a lesser priority of repayment.

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Long-Term Debt - Long-Term Debt Instrument (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Apr. 16, 2014	Jan. 15, 2015
Debt Instrument [Line Items]
Total current portion of long-term debt	$ 27,500,000us-gaap_LongTermDebtCurrent	$ 45,625,000us-gaap_LongTermDebtCurrent
Total notes	623,510,000us-gaap_SeniorNotes	623,471,000us-gaap_SeniorNotes
Long-term credit agreements	522,500,000us-gaap_LineOfCredit	529,375,000us-gaap_LineOfCredit	25,000,000.0us-gaap_LineOfCredit
Total long-term debt	1,146,010,000us-gaap_LongTermDebtNoncurrent	1,152,846,000us-gaap_LongTermDebtNoncurrent
Current portion of long-term debt	27,500,000us-gaap_LongTermDebtCurrent	45,625,000us-gaap_LongTermDebtCurrent
Total debt	1,173,510,000us-gaap_LongTermDebt	1,198,471,000us-gaap_LongTermDebt
5.370% senior notes, Series D, quarterly interest payments, balloon due 2015
Debt Instrument [Line Items]
Current portion of senior notes	0	25,000,000		25,000,000
5.660% senior notes, Series C, semi-annual interest payments, balloon due 2016
Debt Instrument [Line Items]
Total notes	25,000,000	25,000,000
4.500% senior notes, Series E, quarterly interest payments, balloon due 2018
Debt Instrument [Line Items]
Total notes	100,000,000	100,000,000
4.200% senior notes, semi-annual interest payments, balloon due 2024
Debt Instrument [Line Items]
Total notes	498,510,000	498,471,000
5-year term-loan facility, periodic interest and principal payments, currently LIBOR plus 1.375%, expires May 20, 2019
Debt Instrument [Line Items]
Current portion of loan facility	27,500,000	20,625,000
Long-term credit agreements	522,500,000	529,375,000
5-year revolving-loan facility, periodic interest payments, currently LIBOR plus 1.175%, plus commitment fees of 0.20%, expires May 20, 2019
Debt Instrument [Line Items]
Long-term credit agreements	0	0
Revolving credit loan, quarterly interest payments, LIBOR plus up to 1.40% and availability fee up to 0.25%, expires December 31, 2016
Debt Instrument [Line Items]
Long-term credit agreements	$ 0	$ 0