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

Stock-Based Compensation - Assumptions Used to Fair Value Restricted Stock Grants (Details)

v3.24.1.1.u2
Stock-Based Compensation - Assumptions Used to Fair Value Restricted Stock Grants (Details) - Restricted Stock Units (Market Condition)
 12 Months Ended
Mar. 31, 2024
$ / shares
shares
September 2023 Grant  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield (per annum) 0.00%
Expected volatility 35.40%
Risk free interest rate 4.60%
Expected life in years 3 years
JHX stock price at grant date (A$ per share) | $ / shares $ 46.72
Number of restricted stock units (in shares) | shares 451,945
September 2023 Grant  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield (per annum) 0.00%
Expected volatility 38.70%
Risk free interest rate 4.90%
Expected life in years 2 years
JHX stock price at grant date (A$ per share) | $ / shares $ 46.72
Number of restricted stock units (in shares) | shares 7,886
March 2023 Grant  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield (per annum) 0.00%
Expected volatility 36.30%
Risk free interest rate 4.00%
Expected life in years 2 years 4 months 24 days
JHX stock price at grant date (A$ per share) | $ / shares $ 30.98
Number of restricted stock units (in shares) | shares 41,401
November 2022 Grant  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield (per annum) 0.00%
Expected volatility 42.50%
Risk free interest rate 4.70%
Expected life in years 9 months 18 days
JHX stock price at grant date (A$ per share) | $ / shares $ 33.05
Number of restricted stock units (in shares) | shares 38,387
November 2022 Grant  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield (per annum) 0.00%
Expected volatility 35.10%
Risk free interest rate 4.70%
Expected life in years 1 year 9 months 18 days
JHX stock price at grant date (A$ per share) | $ / shares $ 33.05
Number of restricted stock units (in shares) | shares 39,450
November 2022 Grant  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield (per annum) 0.00%
Expected volatility 43.80%
Risk free interest rate 4.70%
Expected life in years 2 years 9 months 18 days
JHX stock price at grant date (A$ per share) | $ / shares $ 33.05
Number of restricted stock units (in shares) | shares 115,688
August 2022 Grant  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield (per annum) 1.50%
Expected volatility 41.90%
Risk free interest rate 3.50%
Expected life in years 3 years
JHX stock price at grant date (A$ per share) | $ / shares $ 33.51
Number of restricted stock units (in shares) | shares 387,360
August 2022 Grant  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield (per annum) 1.50%
Expected volatility 33.40%
Risk free interest rate 3.50%
Expected life in years 2 years
JHX stock price at grant date (A$ per share) | $ / shares $ 33.51
Number of restricted stock units (in shares) | shares 102,250