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Employee Benefit Plans (Tables) | 12 Months Ended
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Mar. 31, 2013
Defined Benefit Plan Disclosure [Line Items] |
Summary of weighted average asset allocation of the plan assets by asset category |
|  | Target Allocation |  |  | March 31, |
|  | 2013 |  |  | 2012 |
Asset Category |  |  |  |  |  |  |  |  |  |  |  |
Equity securities |  |  | 50-70 | % |  |  | 68 | % |  |  | 67 | %
Debt securities |  |  | 20-50 | % |  |  | 32 | % |  |  | 33 | %
Other, including cash |  |  | 0-10 | % |  |  | — | % |  |  | — | %
|  |  |  |  |  |  | 100 | % |  |  | 100 | %
Pension plans, defined benefit [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Components of postretirement benefit income and pension cost |
|  | Year ended March 31, |
|  | 2013 |  |  | 2012 |  |  | 2011 |
Service cost during the period |  | $ | 544 |  |  | $ | 459 |  |  | $ | 384 |
Interest cost on projected benefit obligation |  |  | 1,427 |  |  |  | 1,421 |  |  |  | 1,340 |
Expected return on assets |  |  | (2,738 | ) |  |  | (2,713 | ) |  |  | (2,499 | )
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |
Unrecognized prior service cost |  |  | 4 |  |  |  | 4 |  |  |  | 4 |
Actuarial loss |  |  | 1,011 |  |  |  | 517 |  |  |  | 421 |
Net pension cost (benefit) |  | $ | 248 |  |  | $ | (312 | ) |  | $ | (350 | )
Weighted average actuarial assumptions used to determine net pension cost |
|  | Year ended March 31, |
|  | 2013 |  |  | 2012 |  |  | 2011 |
Discount rate |  |  | 4.76 | % |  |  | 5.63 | % |  |  | 6.07 | %
Rate of increase in compensation levels |  |  | 3.50 | % |  |  | 3.50 | % |  |  | 3.50 | %
Long-term rate of return on plan assets |  |  | 8.50 | % |  |  | 8.50 | % |  |  | 8.50 | %
Changes in the Company's benefit obligation, plan assets and funded status for the plan |
|  | Year ended March 31, |
|  | 2013 |  |  | 2012 |
Change in the benefit obligation |  |  |  |  |  |  |  |
Projected benefit obligation at beginning of year |  | $ | 30,430 |  |  | $ | 25,688 |
Service cost |  |  | 439 |  |  |  | 354 |
Interest cost |  |  | 1,427 |  |  |  | 1,421 |
Actuarial loss |  |  | 1,561 |  |  |  | 3,889 |
Benefit payments |  |  | (1,579 | ) |  |  | (922 | )
Projected benefit obligation at end of year |  | $ | 32,278 |  |  | $ | 30,430 |
Summary of amounts recognized in accumulated other comprehensive loss, net of income tax |
|  | March 31, |
|  | 2013 |  |  | 2012 |
Net actuarial losses |  | $ | 8,278 |  |  | $ | 8,508 |
Prior service cost |  |  | 5 |  |  |  | 7 |
|  | $ | 8,283 |  |  | $ | 8,515 |
Summary of increase/decrease in accumulated other comprehensive loss (income), net of income tax |
|  | March 31, |
|  | 2013 |  |  | 2012 |
Net actuarial loss arising during the year |  | $ | 424 |  |  | $ | 3,434 |
Amortization of actuarial loss |  |  | (653 | ) |  |  | (334 | )
Amortization of prior service cost |  |  | (3 | ) |  |  | (3 | )
|  | $ | (232 | ) |  | $ | 3,097 |
Summary of benefit payments, which reflect future service, are expected to be paid |
2014 |  | $ | 1,184 |
2015 |  |  | 1,244 |
2016 |  |  | 1,230 |
2017 |  |  | 1,331 |
2018 |  |  | 1,416 |
2019-2023 |  |  | 8,030 |
Total |  | $ | 14,435 |
Summary of weighted average asset allocation of the plan assets by asset category |
|  |  |  |  | Fair Value Measurements Using |
Asset Category |  | At March 31, 2013 |  |  | Quoted prices in active markets for identical assets (Level 1) |  |  | Significant other observable inputs (Level 2) |  |  | Significant unobservable inputs (Level 3) |
Cash |  | $ | 108 |  |  | $ | 108 |  |  | $ | — |  |  | $ | — |
Equity securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
U.S. companies |  |  | 19,209 |  |  |  | 19,209 |  |  |  | — |  |  |  | — |
International companies |  |  | 4,284 |  |  |  | 4,284 |  |  |  | — |  |  |  | — |
Fixed income: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Corporate bond funds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Intermediate-term |  |  | 8,953 |  |  |  | 8,953 |  |  |  | — |  |  |  | — |
Short-term |  |  | 2,073 |  |  |  | 2,073 |  |  |  | — |  |  |  | — |
|  | $ | 34,627 |  |  | $ | 34,627 |  |  | $ | — |  |  | $ | — |
|  |  |  |  | Fair Value Measurements Using |
Asset Category |  | At March 31, 2012 |  |  | Quoted prices in active markets for identical assets (Level 1) |  |  | Significant other observable inputs (Level 2) |  |  | Significant unobservable inputs (Level 3) |
Cash |  | $ | 80 |  |  | $ | 80 |  |  | $ | — |  |  | $ | — |
Equity securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
U.S. companies |  |  | 18,021 |  |  |  | 18,021 |  |  |  | — |  |  |  | — |
International companies |  |  | 3,951 |  |  |  | 3,951 |  |  |  | — |  |  |  | — |
Fixed income: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Corporate bond funds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Intermediate-term |  |  | 8,577 |  |  |  | 8,577 |  |  |  | — |  |  |  | — |
Short-term |  |  | 2,039 |  |  |  | 2,039 |  |  |  | — |  |  |  | — |
|  | $ | 32,668 |  |  | $ | 32,668 |  |  | $ | — |  |  | $ | — |
Weighted average actuarial assumptions used to develop the projected benefit obligation |
|  | March 31, |
|  | 2013 |  |  | 2012 |
Discount rate |  |  | 4.28 | % |  |  | 4.76 | %
Rate of increase in compensation levels |  |  | 3.00 | % |  |  | 3.50 | %
Change in fair value of plan assets Fair value of plan assets at beginning of year |  | $ | 32,668 |  |  | $ | 32,368 |
Actual return on plan assets |  |  | 3,538 |  |  |  | 1,222 |
Benefit and administrative expense payments |  |  | (1,579 | ) |  |  | (922 | )
Fair value of plan assets at end of year |  | $ | 34,627 |  |  | $ | 32,668 |
Funded status |  |  |  |  |  |  |  |
Funded status at end of year |  | $ | 2,349 |  |  | $ | 2,238 |
Amount recognized in the Consolidated Balance Sheets |  | $ | 2,349 |  |  | $ | 2,238 |
Other postretirement benefit plans [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Components of postretirement benefit income and pension cost |
|  | Year ended March 31, |
|  | 2013 |  |  | 2012 |  |  | 2011 |
Interest cost on accumulated benefit obligation |  | $ | 39 |  |  | $ | 45 |  |  | $ | 50 |
Amortization of prior service benefit |  |  | (166 | ) |  |  | (166 | ) |  |  | (166 | )
Amortization of actuarial loss |  |  | 44 |  |  |  | 37 |  |  |  | 34 |
Net postretirement benefit income |  | $ | (83 | ) |  | $ | (84 | ) |  | $ | (82 | )
Changes in the Company's benefit obligation, plan assets and funded status for the plan |
|  | Year ended March 31, |
|  | 2013 |  |  | 2012 |
Change in the benefit obligation |  |  |  |  |  |  |  |
Projected benefit obligation at beginning of year |  | $ | 999 |  |  | $ | 999 |
Interest cost |  |  | 39 |  |  |  | 45 |
Actuarial gain |  |  | 95 |  |  |  | 66 |
Benefit payments |  |  | (103 | ) |  |  | (111 | )
Projected benefit obligation at end of year |  | $ | 1,030 |  |  | $ | 999 |
Summary of amounts recognized in accumulated other comprehensive loss, net of income tax |
|  | March 31, |
|  | 2013 |  |  | 2012 |
Net actuarial loss |  | $ | 336 |  |  | $ | 303 |
Prior service cost |  |  | (176 | ) |  |  | (283 | )
|  | $ | 160 |  |  | $ | 20 |
Summary of increase/decrease in accumulated other comprehensive loss (income), net of income tax |
|  | March 31, |
|  | 2013 |  |  | 2012 |
Net actuarial loss arising during the year |  | $ | 61 |  |  | $ | 43 |
Amortization of actuarial loss |  |  | (28 | ) |  |  | (24 | )
Amortization of prior service cost |  |  | 107 |  |  |  | 107 |
|  | $ | 140 |  |  | $ | 126 |
Summary of benefit payments, which reflect future service, are expected to be paid |
2014 |  | $ | 107 |
2015 |  |  | 102 |
2016 |  |  | 96 |
2017 |  |  | 91 |
2018 |  |  | 86 |
2019-2023 |  |  | 352 |
Total |  | $ | 834 |
Weighted average actuarial assumptions used to develop the projected benefit obligation |
|  | March 31, |
|  | 2013 |  |  | 2012 |
Discount rate |  |  | 3.26 | % |  |  | 3.96 | %
Medical care cost trend rate |  |  | 8.00 | % |  |  | 8.00 | %
Change in fair value of plan assets |
|  | Year ended March 31, |
|  | 2013 |  |  | 2012 |
Change in fair value of plan assets |  |  |  |  |  |  |  |
Fair value of plan assets at beginning of year |  | $ | — |  |  | $ | — |
Employer contribution |  |  | 103 |  |  |  | 111 |
Benefit payments |  |  | (103 | ) |  |  | (111 | )
Fair value of plan assets at end of year |  | $ | — |  |  | $ | — |
Funded status |  |  |  |  |  |  |  |
Funded status at end of year |  | $ | (1,030 | ) |  | $ | (999 | )
Amount recognized in the Consolidated Balance Sheets |  | $ | (1,030 | ) |  | $ | (999 | )

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- Definition Tabular disclosure of the assumptions used to determine the defined benefit pension plan or other postretirement plan benefit obligation, including assumed discount rates, rate increase in compensation levels and medical care cost trend rate. + References No definition available. + Details
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- Definition Tabular disclosure of the assumptions used to determine for the pension plan net benefit cost, including assumed discount rates, rate increase in compensation levels, and expected long-term rates of return on plan assets. + References No definition available. + Details
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- Definition Aggregate amount in accumulated other comprehensive income or loss related to defined benefit pension plans or other postretirement plans that will be recognized as a component of net periodic benefit cost in future periods. + References No definition available. + Details
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- Definition Tabular disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans. This information may include, but is not limited to, the target allocation of plan assets, the fair value of each major category of plan assets, and the level within the fair value hierarchy in which the fair value measurements fall. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5) -URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the net gain (loss) and net prior service cost or credit recognized in other comprehensive income (loss) for the period for pension plans and/or other employee benefit plans, and reclassification adjustments of other comprehensive income (loss) for the period, as those amounts, including amortization of the net transition asset or obligation, are recognized as components of net periodic benefit cost. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the reconciliation of beginning and ending balances of the fair value of plan assets of pension plans and/or other employee benefit plans showing separately, if applicable, the effects during the period attributable to each of the following: actual return on plan assets, foreign currency exchange rate changes, contributions by the employer, contributions by plan participants, benefits paid, business combinations, divestitures, and settlements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of the change in the benefit obligation of pension plans and/or other employee benefit plans from the beginning to the end of the period, showing separately, if applicable, the effects of the following: service cost, interest cost, contributions by plan participants, actuarial gains and losses, foreign currency exchange rate changes, benefits paid, plan amendments, business combinations, divestitures, curtailments, settlements, and special and contractual termination benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920 + Details
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- Definition Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920 + Details
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