Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012
Assets, Fair Value Disclosure [Abstract]
Trading securities (short term investments), Fair Value	$ 1,942	$ 1,796
Derivative financial instruments, Fair Value	463	361
Assets, Fair Value Disclosure, Total	2,405	2,157
Liabilities, Fair Value Disclosure [Abstract]
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	4,265	3,530
Deferred compensation obligation, Fair Value	1,943	1,835
Total liabilities, Fair Value	6,208	5,365
Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Trading securities (short term investments), Fair Value	1,932	1,784
Derivative financial instruments, Fair Value	0	0
Assets, Fair Value Disclosure, Total	1,932	1,784
Liabilities, Fair Value Disclosure [Abstract]
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Deferred compensation obligation, Fair Value	1,933	1,823
Total liabilities, Fair Value	1,933	1,823
Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Trading securities (short term investments), Fair Value	10	12
Derivative financial instruments, Fair Value	463	361
Assets, Fair Value Disclosure, Total	473	373
Liabilities, Fair Value Disclosure [Abstract]
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	4,265	3,530
Deferred compensation obligation, Fair Value	10	12
Total liabilities, Fair Value	4,275	3,542
Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Trading securities (short term investments), Fair Value	0	0
Derivative financial instruments, Fair Value	0	0
Assets, Fair Value Disclosure, Total	0	0
Liabilities, Fair Value Disclosure [Abstract]
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Deferred compensation obligation, Fair Value	0	0
Total liabilities, Fair Value	$ 0	$ 0

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

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- Definition

Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

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Derivative instrument obligations meeting the definition of a liability which the Company is a party to as of the balance sheet date.

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This element represents a certain statement of financial position liability caption which represents a class of liabilities, or which may include an individual liability, measured at fair value on a recurring basis.

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This element represents the aggregate of the liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Trading Securities which consist of all investments in certain debt and equity securities that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for which an entity has elected the fair value option. Trading generally reflects active and frequent buying and selling, and trading securities are generally used with the objective of generating profits on short-term differences in price, but this category of investments may also include items which are not intended to be sold in the near term or for which the fair value option has been elected.

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