XML 75 R44.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Restricted Cash and Cash Equivalents - Additional Information (Detail) - USD ($) $ in Millions | Mar. 31, 2017 | Mar. 31, 2016
--- | --- | ---
Cash and Cash Equivalents [Abstract] |  |
Restricted cash and cash equivalents related to insurance policy | $ 5.0 | $ 5.0

X
- Definition Restricted cash and cash equivalents excluding amounts for asbestos claims. + References No definition available. + Details
Name: | jhx_RestrictedCashAndCashEquivalentsExcludingAmountsForAsbestosClaims
Namespace Prefix: | jhx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_CashAndCashEquivalentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration