Stock option plan (Details) (Employee Stock Option [Member], USD $)	0 Months Ended	3 Months Ended	6 Months Ended
Sep. 04, 2014	Apr. 30, 2015	Apr. 30, 2015
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Plan term	10 years
Vesting term	5 years
Vesting rate	20.00%
No. of Options Outstanding
Options outstanding beginning of period			246,000
Options granted during period	246,000
Options outstanding end of period		246,000	246,000
Options expected to vest		238,620	238,620
Options exercisable at end of period
Exercise Price
Options outstanding beginning of period			$ 18.45
Options granted during period	$ 18.45
Options outstanding end of period		$ 18.45	$ 18.45
Compensation expense related to stock options		$ 24,000	$ 47,000
Unrecognized compensation cost		408,000	408,000
Unrecognized compensation cost, recognition period			5 years
Aggregate intrinsic value of options outstanding		$ 442,800	$ 442,800

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Unrecognized cost of unvested options awarded to employees as compensation.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Percentage of vesting of share-based compensation awards.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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The number of exercisable share options (fully vested and expected to vest) that may be converted as of the balance sheet date.

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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