Summary of Significant Accounting Policies (Detail) $ in Thousands			3 Months Ended	12 Months Ended
	Jul. 31, 2016 USD ($)	May. 31, 2016 USD ($)	Mar. 31, 2016 USD ($) contract measurement unit	Dec. 31, 2015 USD ($) contract
Number of contracts in progress that were identified as a loss contract (in contracts) | contract			2	2
Loss on contract termination			$ 3	$ 3
Unbilled receivables, current			9,141	7,312
Billings in excess of cost, current			$ 1,459	$ 1,858
Number of units with APC technology (in units) | unit			1,000
Minimum
Contract term (in months)			8 months
Critical operational measurements (in measurements) | measurement			3
Maximum
Contract term (in months)			16 months
Critical operational measurements (in measurements) | measurement			4
Scenario, Forecast
Decrease in Restricted Cash	$ 1,000	$ 1,000