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Stock-Based Compensation - Assumptions Used for Restricted Stock Grants (Details) - Restricted Stock Units (Market Condition) | 12 Months Ended
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Mar. 31, 2021 $ / shares shares
September 2020 Grant |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Dividend yield (per annum) | 0.00%
Expected volatility | 39.20%
Risk free interest rate | 0.20%
Expected life in years | 2 years 10 months 24 days
JHX stock price at grant date (A$ per share) | $ / shares | $ 30.33
Number of restricted stock units (in shares) | shares | 167,491
November 2020 Grant |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Dividend yield (per annum) | 1.30%
Expected volatility | 40.10%
Risk free interest rate | 0.20%
Expected life in years | 2 years 9 months 18 days
JHX stock price at grant date (A$ per share) | $ / shares | $ 37.24
Number of restricted stock units (in shares) | shares | 127,083
February 2020 Grant |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Dividend yield (per annum) | 2.90%
Expected volatility | 26.60%
Risk free interest rate | 1.20%
Expected life in years | 2 years 6 months
JHX stock price at grant date (A$ per share) | $ / shares | $ 29.54
Number of restricted stock units (in shares) | shares | 6,676
September 2019 Grant |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Dividend yield (per annum) | 3.10%
Expected volatility | 26.60%
Risk free interest rate | 1.60%
Expected life in years | 2 years 10 months 24 days
JHX stock price at grant date (A$ per share) | $ / shares | $ 24.69
Number of restricted stock units (in shares) | shares | 477,979
August 2019 Grant |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Dividend yield (per annum) | 3.10%
Expected volatility | 27.80%
Risk free interest rate | 1.60%
Expected life in years | 2 years
JHX stock price at grant date (A$ per share) | $ / shares | $ 21.68
Number of restricted stock units (in shares) | shares | 18,518

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- Definition Share based compensation arrangement by share based payment award fair value assumptions grant date stock price. + References No definition available. + Details
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- Definition Share based compensation arrangement by share based payment award restricted stock units number. + References No definition available. + Details
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- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(ii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iv) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.D.2) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 + Details
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