| 
           Business combinations (Details 3) (DeltaWare) 
         | 
        12 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|
| 
           Sep. 30, 2014
 
          USD ($) 
         | 
        
           Sep. 30, 2014
 
          CAD 
         | 
        
           Feb. 10, 2010 
         | 
        
           Sep. 30, 2014
 
          Sales targets
 
          USD ($) 
         | 
        
           Sep. 30, 2014
 
          Sales targets
 
          CAD 
         | 
      |
| Business combinations | |||||
| Share capital acquired (as a percent) | 100.00% | ||||
| Contingent consideration payable, based upon sales of acquiree products | 1,000,000 | 4,000,000 | |||
| Sales of acquiree products | 0 | ||||
| Contingent consideration | |||||
| Balance at the beginning of the period | 388,000 | ||||
| Foreign currency translation | (30,000) | ||||
| Balance at the end of the period | $ 358,000 | 
| X | ||||||||||
| 
             
- Definition 
          Represents the maximum amount of contingent consideration payable, based upon sales of acquiree products in particular geographic markets. No definition available. 
  | 
        
| X | ||||||||||
| 
             
- Details 
          
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Represents the amount of sales of acquiree products. No definition available. 
  | 
        
| X | ||||||||||
| 
             
- Details 
          
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Percentage of voting equity interests acquired at the acquisition date in the business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Amount of liability recognized arising from contingent consideration in a business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  |