Summary of Option Activity Under Twenty Zero Four ESOP Plan (Detail) (Stock Option Plan 2004, USD $)	12 Months Ended
Mar. 31, 2013
Stock Option Plan 2004
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options Outstanding, Beginning Balance	135,487
Number of options, Forfeited	375
Number of options Outstanding, Ending Balance	135,112
Number of Options, Exercisable	117,237
Weighted average exercise price Outstanding, Beginning Balance	$ 11.40
Weighted average exercise price, Forfeited	$ 5.16
Weighted average exercise price Outstanding, Ending Balance	$ 11.41
Weighted average exercise price, Exercisable	$ 12.37
Weighted average remaining contractual term, Outstanding	3 years 7 months 6 days
Weighted average remaining contractual term, Exercisable	3 years 2 months 12 days
Aggregate intrinsic value, Outstanding	$ 19,600
Aggregate intrinsic value, Exercisable	$ 12,450

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ 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)(iii)

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

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ 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)(iv)(3)

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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-Publisher FASB

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

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of fully vested and expected to vest options that are exercisable.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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