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)

v3.4.0.3
Stock-Based Compensation - Assumptions Used for Restricted Stock Grants (Detail) - Restricted Stock Units (Market Condition) [Member] - AUD / shares
12 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Date of grant Sep. 16, 2015 Sep. 16, 2015
Dividend yield (per annum) 3.80% 4.50%
Expected volatility 36.80% 37.40%
Risk free interest rate 1.50% 1.60%
Expected life in years 3 years 3 years
JHX stock price at grant date (A$) AUD 17.76 AUD 12.42
Number of restricted stock units 579,262 459,317