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Asbestos - Narrative (Details) $ in Millions, $ in Millions | 12 Months Ended |
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Mar. 31, 2023 USD ($) | Mar. 31, 2023 AUD ($) | Mar. 31, 2022 USD ($) | Mar. 31, 2022 AUD ($) | Mar. 31, 2021 USD ($) | Mar. 31, 2021 AUD ($) | Mar. 31, 2023 AUD ($)
Schedule Of Asbestos Claims [Line Items] |  |  |  |  |  |  |
Secured standby loan facility maximum borrowing capacity | $ 214.8 |  |  |  |  |  | $ 320.0
Restricted Cash and Investments |  |  |  |  |  |  |
Schedule Of Asbestos Claims [Line Items] |  |  |  |  |  |  |
Payment received in accordance with AFFA | $ 109.6 | $ 158.8 | $ 248.5 | $ 328.2 | $ 153.3 | $ 220.9 |
Central Estimate – Discounted and Inflated |  |  |  |  |  |  |
Schedule Of Asbestos Claims [Line Items] |  |  |  |  |  |  |
Discounted actuarial estimate, potential period shift | 2 years | 2 years |  |  |  |  |
Discounted actuarial estimate, potential percent increase | 21.00% |  |  |  |  |  | 21.00%

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