Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

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- Definition

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.

+ References

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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-Subparagraph (SX 210.7-03(a)(16))
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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts 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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- Definition

Sum of the carrying values as of the balance sheet date of the portions of long-term notes payable due within one year or the operating cycle if longer.

+ References

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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 ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Jan. 15, 2015	Apr. 16, 2014
Debt Instrument [Line Items]
Total current portion of long-term debt	$ 80,492,000	$ 73,125,000
Total notes	598,746,000	598,628,000
Long-term credit agreements	440,000,000	481,250,000		$ 25,000,000.0
Debt Issuance Costs, Gross	(7,053,000)	(8,260,000)
Total long-term debt	1,031,693,000	1,071,618,000
Current portion of long-term debt	80,492,000	73,125,000
Total debt	1,112,185,000	1,144,743,000
Notes Payable, Current	492,000	0
5.660% senior notes, Series C, semi-annual interest payments, balloon due 2016
Debt Instrument [Line Items]
Current portion of senior notes	25,000,000	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	498,746,000	498,628,000
5-year term-loan facility, periodic interest and principal payments, LIBOR plus up to 1.75%, expires May 20, 2019
Debt Instrument [Line Items]
Current portion of loan facility	55,000,000	48,125,000
Long-term credit agreements	440,000,000	481,250,000
5-year revolving-loan facility, periodic interest payments, currently LIBOR plus up to 1.50%, plus commitment fees up to 0.25%, expires May 20, 2019
Debt Instrument [Line Items]
Long-term credit agreements	0	$ 0
Revolving Credit Loan Expires In Two Thousand Sixteen [Member]
Debt Instrument [Line Items]
Long-term credit agreements	$ 0
London Interbank Offered Rate (LIBOR) [Member] \| 5-year term-loan facility, periodic interest and principal payments, LIBOR plus up to 1.75%, expires May 20, 2019
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%	1.75%
London Interbank Offered Rate (LIBOR) [Member] \| 5-year revolving-loan facility, periodic interest payments, currently LIBOR plus up to 1.50%, plus commitment fees up to 0.25%, expires May 20, 2019
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.50%	1.50%