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Retirement Plans (Schedule of Assets by Industry Type) (detail) - USD ($) $ in Thousands | Mar. 31, 2016 | Mar. 31, 2015 | Mar. 31, 2014
--- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | $ 176,238 | $ 157,948 | $ 154,650
MoneyMarketFundsMember |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 1,497 | 5,545 |
Equity Securities [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 174,741 | 152,403 |
Equity Securities [Member] | Materials |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 9,379 | 5,460 |
Equity Securities [Member] | Industrials |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 30,355 | 33,813 |
Equity Securities [Member] | Telecommunication services |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 9,325 | 11,393 |
Equity Securities [Member] | Consumer staples |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 33,048 | 23,410 |
Equity Securities [Member] | Energy |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 14,658 | 15,062 |
Equity Securities [Member] | Financials |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 34,891 | 32,808 |
Equity Securities [Member] | Health Care |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 10,538 | 7,503 |
Equity Securities [Member] | Information technology |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | 9,681 | 5,608 |
Equity Securities [Member] | Uitlities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets at beginning of year | $ 22,866 | $ 17,346 |

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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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