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Income Taxes - Reconciled Tax at Statutory Rates (Detail) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2020 | Mar. 31, 2020 | Mar. 31, 2019 | Mar. 31, 2018
Income Tax Disclosure [Abstract] |  |  |  |
Income tax expense computed at the statutory tax rates |  | $ (38.7) | $ (48.9) | $ (24.6)
US state income taxes, net of the federal benefit |  | (5.7) | (3.1) | (4.3)
Asbestos - effect of foreign exchange |  | 20.9 | 14.9 | (1.8)
Expenses not deductible |  | (7.4) | (4.9) | (4.7)
US manufacturing deduction |  | 0.0 | 0.0 | 2.5
Foreign taxes on domestic income |  | (43.5) | (34.5) | (34.2)
Amortization of intangibles |  | 0.0 | 0.0 | 12.4
Taxes on foreign income |  | 2.7 | 4.5 | (3.0)
Net deferred tax liability revaluation |  | (1.8) | 0.2 | 27.7
US net operating loss carryback |  | 25.5 | 0.0 | 0.0
Other items |  | 1.5 | 0.0 | 1.8
Total income tax expense | $ 25.5 | $ (46.5) | $ (71.8) | $ (28.2)
Effective tax rate (as percent) |  | 16.10% | 23.90% | 16.20%

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