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

Asbestos - Numbers of Open Claims, New Claims and Closed Claims and Average Settlement Per Settled Claim and Case Closed (Detail)

v2.4.1.9
Asbestos - Numbers of Open Claims, New Claims and Closed Claims and Average Settlement Per Settled Claim and Case Closed (Detail)
 12 Months Ended
Mar. 31, 2015
USD ($)
Claim
Mar. 31, 2015
AUD
Claim
Mar. 31, 2014
USD ($)
Claim
Mar. 31, 2014
AUD
Claim
Mar. 31, 2013
USD ($)
Claim
Mar. 31, 2013
AUD
Claim
Mar. 31, 2012
USD ($)
Claim
Mar. 31, 2012
AUD
Claim
Mar. 31, 2011
USD ($)
Claim
Mar. 31, 2011
AUD
Claim
Insurance [Abstract]                    
Number of open claims at beginning of period 466us-gaap_LossContingencyPendingClaimsNumber 466us-gaap_LossContingencyPendingClaimsNumber 462us-gaap_LossContingencyPendingClaimsNumber 462us-gaap_LossContingencyPendingClaimsNumber 592us-gaap_LossContingencyPendingClaimsNumber 592us-gaap_LossContingencyPendingClaimsNumber 564us-gaap_LossContingencyPendingClaimsNumber 564us-gaap_LossContingencyPendingClaimsNumber 529us-gaap_LossContingencyPendingClaimsNumber 529us-gaap_LossContingencyPendingClaimsNumber
Number of new claims 665us-gaap_LossContingencyNewClaimsFiledNumber 665us-gaap_LossContingencyNewClaimsFiledNumber 608us-gaap_LossContingencyNewClaimsFiledNumber 608us-gaap_LossContingencyNewClaimsFiledNumber 542us-gaap_LossContingencyNewClaimsFiledNumber 542us-gaap_LossContingencyNewClaimsFiledNumber 456us-gaap_LossContingencyNewClaimsFiledNumber 456us-gaap_LossContingencyNewClaimsFiledNumber 494us-gaap_LossContingencyNewClaimsFiledNumber 494us-gaap_LossContingencyNewClaimsFiledNumber
Number of closed claims 637us-gaap_LossContingencyClaimsSettledAndDismissedNumber 637us-gaap_LossContingencyClaimsSettledAndDismissedNumber 604us-gaap_LossContingencyClaimsSettledAndDismissedNumber 604us-gaap_LossContingencyClaimsSettledAndDismissedNumber 672us-gaap_LossContingencyClaimsSettledAndDismissedNumber 672us-gaap_LossContingencyClaimsSettledAndDismissedNumber 428us-gaap_LossContingencyClaimsSettledAndDismissedNumber 428us-gaap_LossContingencyClaimsSettledAndDismissedNumber 459us-gaap_LossContingencyClaimsSettledAndDismissedNumber 459us-gaap_LossContingencyClaimsSettledAndDismissedNumber
Number of open claims at end of period 494us-gaap_LossContingencyPendingClaimsNumber 494us-gaap_LossContingencyPendingClaimsNumber 466us-gaap_LossContingencyPendingClaimsNumber 466us-gaap_LossContingencyPendingClaimsNumber 462us-gaap_LossContingencyPendingClaimsNumber 462us-gaap_LossContingencyPendingClaimsNumber 592us-gaap_LossContingencyPendingClaimsNumber 592us-gaap_LossContingencyPendingClaimsNumber 564us-gaap_LossContingencyPendingClaimsNumber 564us-gaap_LossContingencyPendingClaimsNumber
Average settlement amount per settled claim $ 222,619jhx_AverageSettlementAmountPerSettledClaim 254,209jhx_AverageSettlementAmountPerSettledClaim $ 236,268jhx_AverageSettlementAmountPerSettledClaim 253,185jhx_AverageSettlementAmountPerSettledClaim $ 238,615jhx_AverageSettlementAmountPerSettledClaim 231,313jhx_AverageSettlementAmountPerSettledClaim $ 228,361jhx_AverageSettlementAmountPerSettledClaim 218,610jhx_AverageSettlementAmountPerSettledClaim $ 193,090jhx_AverageSettlementAmountPerSettledClaim 204,366jhx_AverageSettlementAmountPerSettledClaim
Average settlement amount per case closed $ 190,468jhx_AverageSettlementAmountPerCaseClosed 217,495jhx_AverageSettlementAmountPerCaseClosed $ 198,716jhx_AverageSettlementAmountPerCaseClosed 212,944jhx_AverageSettlementAmountPerCaseClosed $ 206,892jhx_AverageSettlementAmountPerCaseClosed 200,561jhx_AverageSettlementAmountPerCaseClosed $ 207,019jhx_AverageSettlementAmountPerCaseClosed 198,179jhx_AverageSettlementAmountPerCaseClosed $ 163,642jhx_AverageSettlementAmountPerCaseClosed 173,199jhx_AverageSettlementAmountPerCaseClosed