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

Stock-Based Compensation - Assumptions Used for Restricted Stock Grants (Detail)

v2.4.0.8
Stock-Based Compensation - Assumptions Used for Restricted Stock Grants (Detail) (Restricted Stock Units (Market Condition) [Member], AUD)
12 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Restricted Stock Units (Market Condition) [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Date of grant Sep. 16, 2013 Sep. 14, 2012
Dividend yield (per annum) 3.00% 1.50%
Expected volatility 43.30% 52.20%
Risk free interest rate 1.40% 0.70%
Expected life in years 3 years 3 years
JHX stock price at grant date (A$) 10.17 8.95
Number of restricted stock units 489,888 432,654