Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Income Taxes - Deferred Tax Assets and Liabilities (Detail)

v2.4.1.9
Income Taxes - Deferred Tax Assets and Liabilities (Detail) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Mar. 31, 2014
Deferred tax assets:    
Asbestos liability $ 405.2jhx_DeferredTaxAssetsTaxDeferredExpenseAsbestosLiability $ 471.8jhx_DeferredTaxAssetsTaxDeferredExpenseAsbestosLiability
Other provisions and accruals 46.3us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals 52.5us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals
Net operating loss carryforwards 17.0us-gaap_DeferredTaxAssetsOperatingLossCarryforwards 12.8us-gaap_DeferredTaxAssetsOperatingLossCarryforwards
Foreign tax credit carryforwards 107.0us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign 135.4us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign
Total deferred tax assets 575.5us-gaap_DeferredTaxAssetsGross 672.5us-gaap_DeferredTaxAssetsGross
Valuation allowance (113.0)us-gaap_DeferredTaxAssetsValuationAllowance (142.4)us-gaap_DeferredTaxAssetsValuationAllowance
Total deferred tax assets, net of valuation allowance 462.5us-gaap_DeferredTaxAssetsNet 530.1us-gaap_DeferredTaxAssetsNet
Deferred tax liabilities:    
Depreciable and amortizable assets (112.3)us-gaap_DeferredTaxLiabilitiesOtherFiniteLivedAssets (111.2)us-gaap_DeferredTaxLiabilitiesOtherFiniteLivedAssets
Other (3.7)us-gaap_DeferredTaxLiabilitiesOther (6.9)us-gaap_DeferredTaxLiabilitiesOther
Total deferred tax liabilities (116.0)us-gaap_DeferredTaxLiabilities (118.1)us-gaap_DeferredTaxLiabilities
Net deferred tax assets $ 346.5us-gaap_DeferredTaxAssetsLiabilitiesNet $ 412.0us-gaap_DeferredTaxAssetsLiabilitiesNet