Credit Arrangements - Additional Information (Detail)			3 Months Ended
	May 13, 2015 USD ($)	Jan. 27, 2015 USD ($)	Dec. 31, 2018 USD ($)	Nov. 08, 2018 USD ($)	Sep. 30, 2018 USD ($)	May 11, 2018 USD ($)	Dec. 22, 2017 USD ($)	Mar. 31, 2017
Line of Credit Facility [Line Items]
Derivative liability, at fair value			$ 2,000		$ 14,000
Accounts receivable, net			$ 3,706,000		7,418,000
Silicon Valley Bank
Line of Credit Facility [Line Items]
Adjusted quick ratio as above prime rate			2.00%
Foreign receivables accounts	$ 1,000,000
Secured Revolving Line of Credit
Line of Credit Facility [Line Items]
Borrowing capacity under secured revolving line of credit	$ 4,000,000
Notes payable outstanding			$ 879,000		$ 621,000
Annual interest rate			7.50%
Secured Revolving Line of Credit | Silicon Valley Bank
Line of Credit Facility [Line Items]
Credit facility for advances			$ 1,300,000
Second Amended Agreement
Line of Credit Facility [Line Items]
Interest accrued on revolving line of credit			7.50%
Percentage of advance rate on domestic receivables								80.00%
Advance rate on foreign receivables			75.00%
Total term loan		$ 2,500,000
Amortization period of term loan			36 months
Tranche One | Partners for Growth IV, L.P.
Line of Credit Facility [Line Items]
Long-term debt						$ 2,000,000
Tranche Two | Partners for Growth IV, L.P.
Line of Credit Facility [Line Items]
Long-term debt				$ 500,000		500,000
Period Ending September 30, 2017 | Second Amended Agreement
Line of Credit Facility [Line Items]
Maximum change in deferred revenue							$ 0
Period Ending December 31, 2017 | Eleventh Amendment
Line of Credit Facility [Line Items]
Maximum change in deferred revenue							1,900,000
Period Ending March 31, 2018 | Eleventh Amendment
Line of Credit Facility [Line Items]
Maximum change in deferred revenue							0
Period Ending June 30, 2018 | Eleventh Amendment
Line of Credit Facility [Line Items]
Maximum change in deferred revenue							$ 0
Period Ending June 30, 2018 | Twelfth Amendment
Line of Credit Facility [Line Items]
Maximum change in deferred revenue						1,100,000
Period Ending September 30, 2018 | Twelfth Amendment
Line of Credit Facility [Line Items]
Maximum change in deferred revenue						500,000
Period Ending December 31, 2018 | Twelfth Amendment
Line of Credit Facility [Line Items]
Maximum change in deferred revenue						250,000
Period Ending March 31, 2019 | Twelfth Amendment
Line of Credit Facility [Line Items]
Maximum change in deferred revenue						$ 250,000
Each month-end that is the last day of a fiscal quarter | Silicon Valley Bank
Line of Credit Facility [Line Items]
Adjusted quick ratio		1.75
Each month-end that is not the last day of a fiscal quarter | Silicon Valley Bank
Line of Credit Facility [Line Items]
Adjusted quick ratio		1.60