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Debt Instrument, Number of Extension Periods

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Debt Instruments Maturity Year

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Unsecured Revolving Credit Facility

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The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.

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

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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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Amount of the required periodic payments applied to principal.

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

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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 fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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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.

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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.

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The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

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No definition available.

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Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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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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Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

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Carrying value as of the balance sheet date of uncollateralized debt obligation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Long-Term Debt - Narrative (Detail)			3 Months Ended	6 Months Ended
Long-Term Debt - Narrative (Detail)	Sep. 18, 2014 USD ($)	May 20, 2014 USD ($) extension	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Jun. 28, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jan. 15, 2015 USD ($)	Apr. 17, 2014 USD ($)	Sep. 15, 2011 USD ($)	Feb. 01, 2008 USD ($)	Dec. 22, 2006 USD ($)
Debt Instrument [Line Items]
Document Period End Date				Jun. 30, 2017
Credit facility, outstanding amount			$ 375,000,000	$ 375,000,000				$ 426,250,000
Potential increased in line of credit facility										$ 500,000,000.0
Unsecured revolving credit facility							$ 400,000,000.0			800,000,000.0
Write off of Deferred Debt Issuance Cost			200,000
Debt Issuance Costs, Noncurrent, Net							1,600,000
Debt Instrument, Periodic Payment, Principal			5,000,000
Proceeds from Issuance of Debt			2,700,000
Unsecured term loans							$ 395,000,000.0			550,000,000.0
Outstanding debt balance			985,391,000	985,391,000				1,073,872,000
Notes Payable, Current			0	0				500,000
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
Credit Agreement
Debt Instrument [Line Items]
Number of extension periods \| extension		2
Extension period		1 year
Unsecured revolving credit facility										$ 1,350,000,000.0
Unsecured Senior Notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.20%
Debt instrument, face amount	$ 500,000,000.0
Debt instrument maturity year	2024
Outstanding debt balance			500,000,000	500,000,000				500,000,000
Term Loan
Debt Instrument [Line Items]
Credit facility, outstanding amount		$ 550,000,000.0
Debt Instrument, Periodic Payment, Principal			67,500,000.0
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, outstanding amount	$ 475,000,000	$ 375,000,000
Proceeds from lines of credit					$ 0
Uncommitted Facility \| New Master Agreement
Debt Instrument [Line Items]
Credit facility, outstanding amount								$ 0
Master Agreement
Debt Instrument [Line Items]
Unsecured senior notes outstanding			$ 100,000,000	$ 100,000,000
Master Agreement \| Series C
Debt Instrument [Line Items]
Unsecured senior notes outstanding												$ 25,000,000.0	$ 25,000,000.0
Debt instrument interest rate stated percentage													5.66%
Master Agreement \| Series D
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage												5.37%
Master Agreement \| Series E
Debt Instrument [Line Items]
Unsecured senior notes outstanding											$ 100,000,000.0
Debt instrument interest rate stated percentage											4.50%
LIBOR
Debt Instrument [Line Items]
30-day Adjusted LIBOR Rate			1.25%	1.25%
Minimum \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility fee				0.15%
Minimum \| LIBOR \| Term Loan
Debt Instrument [Line Items]
Debt instrument, variable interest rate				1.00%
Minimum \| LIBOR \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, variable interest rate				0.85%
Maximum \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility fee				0.25%
Maximum \| LIBOR \| Term Loan
Debt Instrument [Line Items]
Debt instrument, variable interest rate				1.75%
Maximum \| LIBOR \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, variable interest rate				1.50%
Scenario, Forecast [Member]
Debt Instrument [Line Items]
Unsecured senior notes outstanding						$ 5,000,000