Consolidated funded indebtedness ratio.

No definition available.

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- Definition

Debt instrument calculation of make whole amount description.

+ References

No definition available.

+ Details

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- Definition

Debt instrument permitted minimum aggregate principal amount prepayment without penalty.

+ References

No definition available.

+ Details

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- Definition

Discount on senior notes principal and interest percentage.

+ References

No definition available.

+ Details

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- Definition

Interest coverage ratio minimum.

+ References

No definition available.

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- Definition

Letter of credit maximum capacity.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Number of tranches.

+ References

No definition available.

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

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

+ References

No definition available.

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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

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-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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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.

+ Details

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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.

+ 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(a)(3))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

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- Definition

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

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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-Name Accounting Standards Codification

-Topic 944

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-Section S99

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

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Balance Type:	credit
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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.

+ Details

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- Definition

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

+ References

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Balance Type:	na
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- Definition

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).

+ References

+ Details

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- Definition

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.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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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.

+ References

No definition available.

+ Details

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Balance Type:	credit
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- Definition

The cash outflow for a borrowing supported by a written promise to pay an obligation.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3291-108585

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Long-Term Debt - Additional Information (Detail)		1 Months Ended		6 Months Ended	66 Months Ended	88 Months Ended
Long-Term Debt - Additional Information (Detail)	Oct. 31, 2014	Oct. 31, 2014 USD ($)	Nov. 30, 2012 USD ($)	Sep. 30, 2015 USD ($)	Mar. 31, 2013 USD ($)	Mar. 31, 2013 USD ($)	Mar. 31, 2015 USD ($)	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				$ 327,000,000			$ 330,000,000
Bank Credit Facility, borrowings available				164,000,000
Letter of Credit Facility				50,000,000
Letters of credit outstanding, amount				$ 9,000,000
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 Senior Notes being prepaid at a discount rate equal to the sum of 50 basis points
Discount on Senior Notes principal and interest				0.50%
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 \| Minimum [Member]
Debt Instrument [Line Items]
Variable margin	0.00%
Federal Funds Effective Swap Rate \| Maximum [Member]
Debt Instrument [Line Items]
Variable margin	1.25%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit Facility, principal balance				$ 500,000,000
Credit Facility, maturity date				Oct. 30, 2019
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) LIBOR, plus an agreed margin (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 agreed margin (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 LIBOR advance periods, which can be a period of up to nine months at the option of the Company. 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.
Line of Credit \| Federal Funds Effective Swap Rate \| 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%
Swingline Loan [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit Facility, principal balance				$ 25,000,000
2005 Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Senior Notes, sale									$ 200,000,000
Number of tranches \| Loan									3
Senior Notes, repurchased amount						$ 81,100,000
Senior Notes, payment terms				Interest for each tranche of Notes is payable semi-annually on the 15th day of May and the 15th day of November of each year until all principal is paid for the respective tranche.
2005 Note Purchase Agreement [Member] \| Series 2005A Tranche A [Member]
Debt Instrument [Line Items]
Repayment of Senior Note			$ 4,700,000
2007 Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Senior Notes, sale								$ 200,000,000
Number of tranches \| Loan								4
Senior Notes, repurchased amount					$ 122,000,000
Senior Notes, payment terms				Interest for each tranche of Notes is payable semi-annually on the second day of April and the second day of October of each year until all principal is paid for the respective tranche.
2007 Note Purchase Agreement [Member] \| Series 2007A Tranche A [Member]
Debt Instrument [Line Items]
Repayment of Senior Note		$ 9,500,000