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Antidilutive Securities Excluded from Computation of Earnings, No Net Income from Continuing Operations,Share, Amount

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Estimated Annual Revenue Of Joint Venture

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Basis of Presentation and Accounting Policies - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2019	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Allowance for doubtful accounts	$ 19.6			$ 19.6		$ 17.1
Allowance for certain customer returns, rebates and incentives	$ 13.5			$ 13.5		$ 8.7
Antidilutive share-based compensation awards (in shares)	1.8	0.9		1.8	0.9
Potentially antidilutive securities excluding from computation of earnings per share, amount (in shares)					2.6
Shares to be included if recorded net income from continuing operations (in shares)					1.7
Capital expenditures in accounts payable or other current liabilities at period end				$ 11.1	$ 14.0
Outstanding purchase of common stock recorded in accounts payable				$ 11.9	$ 12.3
Scenario, Forecast \| Sensia
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Payments to acquire interest in joint venture			$ 250.0
Schlumberger \| Scenario, Forecast \| Sensia
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners			47.00%
ROCKWELL AUTOMATION INC. \| Scenario, Forecast \| Sensia
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ownership percentage			53.00%
Sensia \| Scenario, Forecast
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenues			$ 400.0