Equity (Schedule of Common Stock Reserved for Future Issuances) (Details) - shares	Mar. 31, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise of outstanding stock options (in shares)	68,453	69,980
Purchases under the employee stock purchase plan (in shares)	674,152
Issuance of stock-based awards under the Equity Plans (in shares)	3,621,906
Purchases under the officer and director share purchase plan (in shares)	88,741
Total reserved (in shares)	5,731,313
Restricted stock units and awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock units (in shares)	742,747
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested award potential, percentage	200.00%
Unvested stock units (in shares)	234,324	397,777
Unvested performance stock units (in shares)	535,314

Common Stock, Stock-based Awards Reserved for Future Issuance

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- Definition

Employee Stock Purchase Plan (ESPP), Shares Reserved for Future Issuances

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Officer and Director Share Purchase Plan, Shares Reserved for Future Issuances

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Maximum Award Potential

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Maximum Award Potential, Percentage

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of options outstanding, including both vested and non-vested options.

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-Topic 718
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