Income Taxes - Effective Tax Rate Reconciliation (Details)	12 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory tax rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	0.80%	0.60%	0.00%
Foreign tax differentials	(8.40%)	(12.50%)	(13.80%)
Foreign tax holiday	(2.60%)	(4.30%)	(3.00%)
U.S. taxes on foreign earnings	1.70%	(0.90%)	(0.30%)
Other credit and incentives	(0.30%)	(0.30%)	(0.10%)
Domestic production activities	(0.30%)	(0.00%)	(0.00%)
Valuation allowance	(6.90%)	(2.80%)	1.80%
Other	2.10%	(0.60%)	0.00%
Effective Tax Rate	21.10%	14.20%	19.60%

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32698-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32698-109319

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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.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32687-109319

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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 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 income exempt from income tax because of a tax holiday.

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Effective Income Tax Rate Reconciliation Tax Credits Net Of Repatriation Of Foreign Earnings

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