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Revenue and Vendor Concentrations - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Revenue, Major Customer [Line Items]
Revenue	$ 9,670	$ 9,105	$ 8,522	$ 7,404	$ 7,866	$ 6,440	$ 5,672	$ 5,389	$ 5,544	$ 4,660	$ 4,484	$ 4,463	$ 34,701	$ 25,367	$ 19,150
Accounts receivable, net	4,949				3,937								4,949	3,937
Customer Concentration Risk [Member]
Revenue, Major Customer [Line Items]
Revenue													$ 6,300	$ 6,300	$ 5,700
Customer Concentration Risk [Member] \| Sales Revenue Net [Member]
Revenue, Major Customer [Line Items]
Total revenue, percentage													10.00%	10.00%	10.00%
Geographic Concentration Risk [Member] \| Sales Revenue Net [Member]
Revenue, Major Customer [Line Items]
Total revenue, percentage													15.00%	5.00%	4.00%
Customer One [Member] \| Customer Concentration Risk [Member] \| Sales Revenue Net [Member]
Revenue, Major Customer [Line Items]
Total revenue, percentage													18.00%	25.00%	30.00%
Major Customers [Member] \| Customer Concentration Risk [Member]
Revenue, Major Customer [Line Items]
Accounts receivable, net	$ 1,000				$ 1,100				$ 1,400				$ 1,000	$ 1,100	$ 1,400
Channel Partners [Member] \| Supplier Concentration Risk [Member] \| Sales Revenue Net [Member]
Revenue, Major Customer [Line Items]
Total revenue, percentage													10.00%