Summary of Significant Accounting Policies and Select Balance Sheet Information - Summary of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Schedule of Investments [Line Items]
Other assets, net	$ 628	$ 479
ViaCyte, Inc. [Member]
Schedule of Investments [Line Items]
Other assets, net	479	$ 479
Other Noncurrent Assets [Member]
Schedule of Investments [Line Items]
Other assets, net	$ 149

Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_OtherAssetsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant