XML 67 R62.htm IDEA: XBRL DOCUMENT v2.4.1.9

Product Warranties - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Limited warranty period	30 years

X

- Definition

Limited warranty period.

+ References

No definition available.

+ Details

Name:	jhx_LimitedWarrantyPeriod
Namespace Prefix:	jhx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration