Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Effective Tax Rate Reconciliation
Statutory tax rate	21.00%	21.00%	24.50%
State and local income taxes	0.80%	0.10%	1.00%
Non-United States taxes	(5.20%)	(4.80%)	(4.40%)
Repatriation of foreign earnings	1.30%	2.80%	4.20%
Foreign-derived intangible income	(1.00%)	(1.60%)	0.00%
Impact of the Tax Act	0	0	0.366
Sensia formation	(1.10%)	0.00%	0.00%
Change in valuation allowance	(2.70%)	7.60%	0.70%
Share-based compensation	1.90%	0.90%	1.30%
Research and development tax credit	1.10%	1.20%	1.30%
Other	(0.20%)	(0.20%)	(0.20%)
Effective income tax rate	9.90%	22.80%	59.80%
PTC
Effective Tax Rate Reconciliation
Change in valuation allowance	2.70%
Effective income tax rate reconciliation, change in deferred tax assets valuation allowance, amount	$ 30.1

Effective Income Tax Rate Reconciliation, Business Combination, Percent

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Percentage of the difference between the reported income tax expense and expected income tax expense computed by applying the domestic federal statutory income tax rates to pretax income attributable to the excess income tax benefit from share-based compensation.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to the repatriation of foreign earnings and deemed income, net of related foreign tax credits.

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Effective income tax rate reconciliation, foreign-derived intangible income

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Percentage of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to Tax Cuts and Jobs Act.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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