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Employee Benefit Plans - Fair Values of Company's Pension Plan Assets by Asset Category (Detail) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Thousands | Mar. 31, 2016 | Mar. 31, 2015 | Mar. 31, 2014
--- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | $ 36,471 | $ 40,384 | $ 38,548
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 36,471 | 40,384 |
Cash [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 103 | 126 |
Cash [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 103 | 126 |
U.S. companies, Equity Securities [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 20,010 | 21,586 |
U.S. companies, Equity Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 20,010 | 21,586 |
International companies, Equity Securities [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 4,459 | 4,854 |
International companies, Equity Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 4,459 | 4,854 |
Fixed income, Corporate bond funds, Intermediate-term [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 9,520 | 11,109 |
Fixed income, Corporate bond funds, Intermediate-term [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 9,520 | 11,109 |
Fixed income, Corporate bond funds, Short-term [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 2,379 | 2,709 |
Fixed income, Corporate bond funds, Short-term [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | $ 2,379 | $ 2,709 |

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- Definition Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 30 -Section 35 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=49178875&loc=d3e12355-114930 Reference 2: 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=58740216&loc=d3e1928-114920 + Details
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