Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Assets
Available-for-sale securities	$ 6,135	$ 133,308
Fair Value, Measurements, Recurring
Assets
Cash equivalents	143	11,628
Available-for-sale securities	6,135	133,308
Foreign exchange contracts, Assets	5
Stock warrant	45	59
Total Assets	12,102	150,421
Liabilities
Contingent consideration	500	811
Foreign exchange contracts, Liabilities	97	36
Total Liabilities	597	847
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash equivalents	98	10,133
Available-for-sale securities	0	0
Stock warrant	0	0
Total Assets	98	10,133
Liabilities
Contingent consideration	0	0
Foreign exchange contracts, Liabilities	0	0
Total Liabilities	0	0
Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets
Cash equivalents	45	1,495
Available-for-sale securities	6,135	133,308
Foreign exchange contracts, Assets	5	89
Stock warrant	0	0
Total Assets	6,185	134,892
Liabilities
Contingent consideration	0	0
Foreign exchange contracts, Liabilities	97	36
Total Liabilities	97	36
Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Assets
Cash equivalents	0	0
Available-for-sale securities	0	0
Foreign exchange contracts, Assets	0	0
Stock warrant	45	59
Total Assets	5,819	5,396
Liabilities
Contingent consideration	500	811
Foreign exchange contracts, Liabilities	0	0
Total Liabilities	500	811
Convertible Debt Securities [Member] \| Fair Value, Measurements, Recurring
Assets
Convertible debt securities	5,774	5,337
Convertible Debt Securities [Member] \| Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Convertible debt securities	0	0
Convertible Debt Securities [Member] \| Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets
Convertible debt securities	0	0
Convertible Debt Securities [Member] \| Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Assets
Convertible debt securities	$ 5,774	$ 5,337

Stock Warrants Assets, Fair Value Disclosure

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
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Amount of liability recognized arising from contingent consideration in a business combination.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6507016

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Fair value portion of asset contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward contracts, and swaps.

+ References

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Fair value portion of liability contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward (delivery or nondelivery) contracts, and swaps entered into.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Trading Securities
-URI http://asc.fasb.org/extlink&oid=6526789

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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 1
-Subparagraph a, f, g
-Article 7

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Aggregation of the liabilities reported on the balance sheet measured at fair value on a recurring basis by the entity.

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