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Asbestos - Asbestos Adjustments (Detail) - USD ($) $ in Millions | 12 Months Ended
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Mar. 31, 2016 | Mar. 31, 2015 | Mar. 31, 2014
Change in estimates: |  |  |
Change in actuarial estimate - asbestos liability | $ 2.4 | $ (129.0) | $ (340.3)
Change in actuarial estimate - insurance receivable | 4.5 | 16.6 | 31.2
Change in estimate - AICF claims-handling costs | 1.2 | 1.1 | 0.9
Subtotal - Change in estimates | 8.1 | (111.3) | (308.2)
Recovery of Insurance Receivables |  |  | 15.2
(Loss) gain on foreign currency exchange | (2.6) | 144.7 | 97.2
Total Asbestos Adjustments | $ 5.5 | $ 33.4 | $ (195.8)

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- Definition Gain (loss) on foreign exchange movements in the other asbestos related assets and liabilities which are denominated in Australian dollars. + References No definition available. + Details
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- Definition Comprised of changes in actuarial estimates received as of March 31 each year and the effect of foreign exchange movements in the asbestos related assets and liabilities which are denominated in Australian dollars. + References No definition available. + Details
Name: | jhx_AsbestosAdjustments
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- Definition Change in actuarial estimate asbestos liability. + References No definition available. + Details
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- Definition Change in actuarial estimate insurance receivables. + References No definition available. + Details
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- Definition Change in estimate claims handling costs. + References No definition available. + Details
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- Definition Change in estimates. + References No definition available. + Details
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- Definition Changes in estimates. + References No definition available. + Details
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- Definition The change in asbestos adjustments associated with the recovery of insurance receivables associated with the asbestos related liability. + References No definition available. + Details
Name: | jhx_RecoveryOfInsuranceReceivablesAsbestos
Namespace Prefix: | jhx_
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