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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

+ References

+ Details

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a, b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

- Definition

The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

+ References

+ Details

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- Definition

Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- Definition

The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

+ Details

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Stock Options and Stock-Based Compensation (Details 3) (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Stock options outstanding and exercisable
Number of Outstanding Options	550,476
Weighted Average Remaining Contractual Life	3 years 6 months 4 days
Price range of outstanding options	$ 37.31
Exercisable options	278,962	388,154	374,141
Exercisable Options-Weighted Average Exercise Price	$ 29.51
Range of Exercise Price, $15.55 to $26.85 [Member]
Stock options outstanding and exercisable
Range of Exercise Price, lower limit	$ 15.55
Range of Exercise Price, upper limit	$ 26.85
Number of Outstanding Options	132,822
Weighted Average Remaining Contractual Life	2 years 6 months 0 days
Price range of outstanding options	$ 20.92
Exercisable options	121,623
Exercisable Options-Weighted Average Exercise Price	$ 20.72
Range of Exercise Price, $26.86 to $40.16 [Member]
Stock options outstanding and exercisable
Range of Exercise Price, lower limit	$ 26.86
Range of Exercise Price, upper limit	$ 40.16
Number of Outstanding Options	148,000
Weighted Average Remaining Contractual Life	2 years 8 months 16 days
Price range of outstanding options	$ 33.67
Exercisable options	117,870
Exercisable Options-Weighted Average Exercise Price	$ 32.77
Range of Exercise Price, $40.17 to $46.70 [Member]
Stock options outstanding and exercisable
Range of Exercise Price, lower limit	$ 40.17
Range of Exercise Price, upper limit	$ 46.70
Number of Outstanding Options	138,981
Weighted Average Remaining Contractual Life	4 years 8 months 9 days
Price range of outstanding options	$ 44.66
Exercisable options	28,292
Exercisable Options-Weighted Average Exercise Price	$ 45.42
Range of Exercise Price, $46.71 to $52.76 [Member]
Stock options outstanding and exercisable
Range of Exercise Price, lower limit	$ 46.71
Range of Exercise Price, upper limit	$ 52.76
Number of Outstanding Options	130,673
Weighted Average Remaining Contractual Life	4 years 2 months 5 days
Price range of outstanding options	$ 50.28
Exercisable options	11,177
Exercisable Options-Weighted Average Exercise Price	$ 50.55