Subsequent events - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 22, 2015	Oct. 31, 2015	Oct. 31, 2014	Dec. 16, 2015
Subsequent Event [Line Items]
Proceeds from Sale of Productive Assets, Total		$ 16,000	$ 0
Subsequent Event
Subsequent Event [Line Items]
Dividends Payable, Amount Per Share				$ 0.07
Subsequent Event | Aviel Electronics Division [Member]
Subsequent Event [Line Items]
Proceeds from Sale of Productive Assets, Total	$ 400,000
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents	150,000
Disposal Group, Including Discontinued Operation, Consideration	884,000
Proceeds from Divestiture of Businesses	1,176,000
Subsequent Event | Aviel Electronics Division [Member] | Notes Payable, Other Payables [Member]
Subsequent Event [Line Items]
Disposal Group, Including Discontinued Operation, Accounts Payable	$ 250,000
Debt Instrument, Interest Rate, Stated Percentage	5.00%
Debt Instrument, Term	3 years