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Commitments and Contingencies - Additional Information (Details) - claim | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Mar. 31, 2016 | Mar. 31, 2021 | Mar. 31, 2020 | Mar. 31, 2019 | Mar. 31, 2018 | Mar. 31, 2017
Loss Contingencies [Line Items] |  |  |  |  |  |
Number of pending claims | 426 | 360 | 393 | 332 | 336 | 352
New Zealand | Subsidiaries | New Zealand Weathertightness |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |
Number of claims | 4 |  |  |  |  |
Number of pending claims | 3 |  |  |  |  |

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- Definition The total number of new claims filed pertaining to a loss contingency during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349 + Details
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