Consolidated funded indebtedness ratio.

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Debt instrument calculation of make whole amount description.

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No definition available.

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- Definition

Debt instrument covenant percentage of consolidated assets.

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No definition available.

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Debt Instrument covenant percentage of consolidated revenues.

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No definition available.

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Debt instrument maturity period.

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No definition available.

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- Definition

Debt instrument permitted minimum aggregate principal amount prepayment without penalty.

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No definition available.

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- Definition

Discount on senior notes principal and interest percentage.

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No definition available.

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- Definition

Interest coverage ratio minimum.

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No definition available.

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- Definition

Letter of credit maximum capacity.

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No definition available.

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Number of tranches.

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No definition available.

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- Definition

Percentage of face value to be paid if notes are prepaid.

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No definition available.

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- Definition

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

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No definition available.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
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-Paragraph 1
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-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
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- Definition

Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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- Definition

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

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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.

+ References

No definition available.

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- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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Percentage of principal amount of debt redeemed.

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No definition available.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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No definition available.

+ Details

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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.

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- Definition

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.

+ References

No definition available.

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Date the credit facility terminates, in CCYY-MM-DD format.

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Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

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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 of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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No definition available.

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- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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No definition available.

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Long-Term Debt - Additional Information (Detail)			1 Months Ended	9 Months Ended
Long-Term Debt - Additional Information (Detail)	Aug. 02, 2016 USD ($)	Oct. 31, 2014	Oct. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2017 USD ($)	Oct. 02, 2007 USD ($) Loan	Nov. 15, 2005 USD ($) Loan
Debt Instrument [Line Items]
Interest coverage ratio		250.00%
Unused line of credit commitment fee based on leverage ratio		0.10%
Borrowings outstanding under Credit Facility				$ 185,000,000	$ 225,000,000
Bank Credit Facility, borrowings available				305,600,000
Letter of Credit Facility				40,000,000
Letters of credit outstanding, amount				$ 9,400,000
Maximum [Member]
Debt Instrument [Line Items]
Consolidated funded indebtedness ratio		350.00%
Unused line of credit commitment fee based on leverage ratio		0.35%
London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Variable margin		1.00%
London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Variable margin		2.25%
Federal Funds Effective Swap Rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Variable margin		0.00%
Federal Funds Effective Swap Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Variable margin		1.25%
4.500% Senior Unsecured Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt instrument, principal amount	$ 350,000,000
Debt instrument, interest rate	4.50%			4.50%
Debt instrument, maturity period	2026-08
4.500% Senior Unsecured Notes Due 2026 [Member] \| Prior to August 1, 2019 [Member]
Debt Instrument [Line Items]
Redemption price, percentage	104.50%
4.500% Senior Unsecured Notes Due 2026 [Member] \| On or After August 1, 2019 and Prior to August 1, 2021 [Member]
Debt Instrument [Line Items]
Redemption price, percentage	100.00%
4.500% Senior Unsecured Notes Due 2026 [Member] \| Maximum [Member] \| Prior to August 1, 2019 [Member]
Debt Instrument [Line Items]
Percentage of principal amount redeemable	40.00%
2005 Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Senior Notes, sale							$ 200,000,000
Number of tranches \| Loan							3
2007 Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Interest coverage ratio				250.00%
Senior Notes, sale						$ 200,000,000
Number of tranches \| Loan						4
Senior Notes, payment terms				Interest for each tranche of Notes is payable semi-annually April 2 and October 2 of each year until all principal is paid for the respective tranche.
Purchase agreement additional requirements				and to maintain an interest coverage ratio (Consolidated EBITDA to Consolidated Interest Expense (calculated as consolidated EBITDA, as defined above, to consolidated interest expense)) of at least 2.50:1.00. In addition, the 2007 Note Purchase Agreement requires the Company to ensure that at all times either (i) Consolidated Total Assets equal at least 80% of the consolidated total assets of the Company and its Subsidiaries, determined in accordance with GAAP, or (ii) consolidated total revenues of the Company and its Restricted Subsidiaries for the period of four consecutive fiscal quarters most recently ended equals at least 80% of the consolidated total revenues of the Company and its Subsidiaries during such period.
Senior Notes, permitted minimum aggregate principal amount prepayment without penalty				10.00%
Percentage of face value to be paid if notes are prepaid				100.00%
Senior Notes, calculation of make-whole amount, description				Discounting the remaining scheduled payments of interest and principal of the Private Placement Senior Unsecured Notes being prepaid at a discount rate equal to the sum of 50 basis
Discount on Senior Notes principal and interest				0.50%
2007 Note Purchase Agreement [Member] \| Series 2007A Tranche C [Member]
Debt Instrument [Line Items]
Repayments of debt			$ 24,000,000
2007 Note Purchase Agreement [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Percentage of consolidated assets require to maintain				80.00%
Percentage of consolidated revenues require to maintain				80.00%
2007 Note Purchase Agreement [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Consolidated funded indebtedness ratio				350.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit Facility, principal balance				$ 500,000,000
Credit Facility, termination date				Aug. 02, 2021
Credit Facility, interest rate description				At the option of the Company, outstanding principal amounts on the Credit Facility bear interest at a variable rate equal to (i) The London Interbank Offered Rate (“LIBOR”) for the selected period, plus an applicable rate (ranging from 100 to 225 basis points), which is to be established quarterly based upon the Company’s ratio of consolidated EBITDA, defined as earnings before interest, taxes, depreciation and amortization, to the Company’s consolidated indebtedness (the “Leverage Ratio”), or (ii) an alternative base rate which is the higher of (a) the prime rate or (b) the federal funds rate plus 1⁄2% per annum plus an applicable rate (ranging from 0 to 125 basis points). Interest payments are payable, in the case of loans bearing interest at a rate based on the federal funds rate, quarterly, or in the case of loans bearing interest at a rate based on LIBOR, at the end of the applicable interest period. The Company is also required to pay a commitment fee on unused available borrowings under the Credit Facility ranging from 10 to 35 basis points depending upon the Leverage Ratio.
Revolving Credit Facility [Member] \| Swingline Loan [Member]
Debt Instrument [Line Items]
Credit Facility, principal balance				$ 25,000,000
Line of Credit \| Federal Funds Effective Swap Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Variable margin		0.50%
Letter of Credit [Member]
Debt Instrument [Line Items]
Bank Credit Facility, one-time fee				0.125%