| Segment reporting | 
    |   | 
  | 
    Three Months Ended
    June 30, | 
  | 
  | 
    Nine Months Ended
    June 30, | 
  | 
 
    |   | 
  | 
    2018 | 
  | 
  | 
    2017 | 
  | 
  | 
    2018 | 
  | 
  | 
    2017 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
      | 
  | 
  | 
      | 
  | 
  | 
      | 
  | 
 
    | Revenues | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Retail and Online | 
  | 
    $ | 
29,705,192 | 
  | 
  | 
    $ | 
19,267,959 | 
  | 
  | 
    $ | 
82,182,175 | 
  | 
  | 
    $ | 
54,020,215 | 
  | 
 
    | Manufacturing | 
  | 
      | 
24,773,123 | 
  | 
  | 
      | 
21,898,645 | 
  | 
  | 
      | 
64,460,280 | 
  | 
  | 
      | 
57,429,871 | 
  | 
 
    | Services | 
  | 
      | 
183,742 | 
  | 
  | 
      | 
210,889 | 
  | 
  | 
      | 
567,594 | 
  | 
  | 
      | 
652,496 | 
  | 
 
    |   | 
  | 
    $ | 
54,662,057 | 
  | 
  | 
    $ | 
41,377,493 | 
  | 
  | 
    $ | 
147,210,049 | 
  | 
  | 
    $ | 
112,102,582 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Gross profit | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Retail and Online | 
  | 
    $ | 
12,141,262 | 
  | 
  | 
    $ | 
10,953,602 | 
  | 
  | 
    $ | 
38,133,949 | 
  | 
  | 
    $ | 
30,105,864 | 
  | 
 
    | Manufacturing | 
  | 
      | 
6,498,207 | 
  | 
  | 
      | 
5,839,412 | 
  | 
  | 
      | 
16,187,021 | 
  | 
  | 
      | 
15,388,787 | 
  | 
 
    | Services | 
  | 
      | 
174,749 | 
  | 
  | 
      | 
200,883 | 
  | 
  | 
      | 
539,839 | 
  | 
  | 
      | 
619,848 | 
  | 
 
    |   | 
  | 
    $ | 
18,814,218 | 
  | 
  | 
    $ | 
16,993,897 | 
  | 
  | 
    $ | 
54,860,809 | 
  | 
  | 
    $ | 
46,114,499 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Operating income (loss) | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Retail and Online | 
  | 
    $ | 
(1,978,657 | 
) | 
  | 
    $ | 
2,268,438 | 
  | 
  | 
    $ | 
2,644,667 | 
  | 
  | 
    $ | 
6,547,564 | 
  | 
 
    | Manufacturing | 
  | 
      | 
2,703,380 | 
  | 
  | 
      | 
2,915,516 | 
  | 
  | 
      | 
5,710,457 | 
  | 
  | 
      | 
7,168,164 | 
  | 
 
    | Services | 
  | 
      | 
173,097 | 
  | 
  | 
      | 
199,173 | 
  | 
  | 
      | 
537,447 | 
  | 
  | 
      | 
617,324 | 
  | 
 
    |   | 
  | 
    $ | 
897,820 | 
  | 
  | 
    $ | 
5,383,127 | 
  | 
  | 
    $ | 
8,892,571 | 
  | 
  | 
    $ | 
14,333,052 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Depreciation and amortization | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Retail and Online | 
  | 
    $ | 
988,169 | 
  | 
  | 
    $ | 
329,416 | 
  | 
  | 
    $ | 
2,106,133 | 
  | 
  | 
    $ | 
884,522 | 
  | 
 
    | Manufacturing | 
  | 
      | 
833,064 | 
  | 
  | 
      | 
760,125 | 
  | 
  | 
      | 
2,418,264 | 
  | 
  | 
      | 
2,228,264 | 
  | 
 
    | Services | 
  | 
      | 
– | 
  | 
  | 
      | 
– | 
  | 
  | 
      | 
– | 
  | 
  | 
      | 
– | 
  | 
 
    |   | 
  | 
    $ | 
1,821,233 | 
  | 
  | 
    $ | 
1,089,541 | 
  | 
  | 
    $ | 
4,524,397 | 
  | 
  | 
    $ | 
3,112,786 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Interest expenses | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Retail and Online | 
  | 
    $ | 
2,223,285 | 
  | 
  | 
    $ | 
1,600,589 | 
  | 
  | 
    $ | 
5,594,983 | 
  | 
  | 
    $ | 
4,283,015 | 
  | 
 
    | Manufacturing | 
  | 
      | 
487,997 | 
  | 
  | 
      | 
527,201 | 
  | 
  | 
      | 
1,406,331 | 
  | 
  | 
      | 
1,329,304 | 
  | 
 
    | Services | 
  | 
      | 
– | 
  | 
  | 
      | 
– | 
  | 
  | 
      | 
– | 
  | 
  | 
      | 
– | 
  | 
 
    |   | 
  | 
    $ | 
2,711,282 | 
  | 
  | 
    $ | 
2,127,790 | 
  | 
  | 
    $ | 
7,001,314 | 
  | 
  | 
    $ | 
5,612,319 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Net income before provision for income taxes | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Retail and Online | 
  | 
    $ | 
(503,861 | 
) | 
  | 
    $ | 
797,504 | 
  | 
  | 
    $ | 
4,710,315 | 
  | 
  | 
    $ | 
2,842,206 | 
  | 
 
    | Manufacturing | 
  | 
      | 
2,232,996 | 
  | 
  | 
      | 
2,175,749 | 
  | 
  | 
      | 
4,316,045 | 
  | 
  | 
      | 
5,363,455 | 
  | 
 
    | Services | 
  | 
      | 
173,097 | 
  | 
  | 
      | 
294,736 | 
  | 
  | 
      | 
537,447 | 
  | 
  | 
      | 
712,886 | 
  | 
 
    |   | 
  | 
    $ | 
1,902,232 | 
  | 
  | 
    $ | 
3,267,989 | 
  | 
  | 
    $ | 
9,563,807 | 
  | 
  | 
    $ | 
8,918,547 | 
  | 
 
 
  
  
    |   | 
  | 
    As of  June 30,
     2018 | 
  | 
  | 
    As of  September
    30,  
    2017 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
      | 
  | 
 
    | Total assets | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Retail and Online | 
  | 
    $ | 
88,761,358 | 
  | 
  | 
    $ | 
81,703,371 | 
  | 
 
    | Manufacturing | 
  | 
      | 
52,942,685 | 
  | 
  | 
      | 
46,783,429 | 
  | 
 
    | Services | 
  | 
      | 
101,379 | 
  | 
  | 
      | 
107,795 | 
  | 
 
    |   | 
  | 
    $ | 
141,805,422 | 
  | 
  | 
    $ | 
128,594,595 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Goodwill and intangible assets | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
 
    | Retail and Online | 
  | 
    $ | 
43,612,119 | 
  | 
  | 
    $ | 
40,778,865 | 
  | 
 
    | Manufacturing | 
  | 
      | 
351,233 | 
  | 
  | 
      | 
373,184 | 
  | 
 
    | Services | 
  | 
      | 
– | 
  | 
  | 
      | 
– | 
  | 
 
    |   | 
  | 
    $ | 
43,963,352 | 
  | 
  | 
    $ | 
41,152,049 | 
  | 
 
 
  
 |