Supplemental Balance Sheet Information - Schedule of supplemental balance sheet information (Details) - USD ($) $ in Millions	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Short-term restricted cash included in other current assets	$ 0.4		$ 0.8
Trade accounts receivable reserves	24.6	$ 22.8
Accumulated depreciation on property, plant, and equipment	322.3	309.0
Inventories, net:
Raw materials and components	138.0	72.3
Work in process	101.3	44.0
Finished goods	184.0	60.3
Total inventories, net	$ 423.3	$ 176.6

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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