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

Restricted Cash and Cash Equivalents - Additional Information (Detail)

v2.4.1.9
Restricted Cash and Cash Equivalents - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Mar. 31, 2014
Cash and Cash Equivalents [Abstract]    
Restricted cash and cash equivalents related to insurance policy $ 5.0jhx_RestrictedCashAndCashEquivalentsRelatedToInsurancePolicy $ 5.0jhx_RestrictedCashAndCashEquivalentsRelatedToInsurancePolicy