Other Assets - Summary of Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Sep. 30, 2015
Schedule of Investments [Line Items]
Other assets, net	$ 650	$ 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	$ 171