| Segment reporting | 
    |  |  | Three Months Ended June 30, |  |  | Nine Months Ended June 30, |  |  
    |  |  | 2017 |  |  | 2016 |  |  | 2017 |  |  | 2016 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Revenues |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Retail and Online |  | $ | 19,267,959 |  |  | $ | 508,099 |  |  | $ | 54,020,215 |  |  | $ | 5,284,851 |  |  
    | Manufacturing |  |  | 21,898,645 |  |  |  | 19,243,019 |  |  |  | 57,429,871 |  |  |  | 53,881,143 |  |  
    | Services |  |  | 210,889 |  |  |  | 243,245 |  |  |  | 652,496 |  |  |  | 772,726 |  |  
    |  |  | $ | 41,377,493 |  |  | $ | 19,994,363 |  |  | $ | 112,102,582 |  |  | $ | 59,938,720 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Gross profit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Retail and Online |  | $ | 10,953,602 |  |  | $ | (616,754 | ) |  | $ | 30,105,864 |  |  | $ | 1,233,705 |  |  
    | Manufacturing |  |  | 5,839,412 |  |  |  | 5,483,896 |  |  |  | 15,388,787 |  |  |  | 15,143,363 |  |  
    | Services |  |  | 200,883 |  |  |  | 232,272 |  |  |  | 619,848 |  |  |  | 738,420 |  |  
    |  |  | $ | 16,993,897 |  |  | $ | 5,099,414 |  |  | $ | 46,114,499 |  |  | $ | 17,115,488 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Operating income (loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Retail and Online |  | $ | 2,268,438 |  |  | $ | (2,228,857 | ) |  | $ | 6,547,564 |  |  | $ | (4,378,431 | ) |  
    | Manufacturing |  |  | 2,915,516 |  |  |  | 3,055,516 |  |  |  | 7,168,164 |  |  |  | 6,946,781 |  |  
    | Services |  |  | 199,173 |  |  |  | 230,559 |  |  |  | 617,324 |  |  |  | 734,598 |  |  
    |  |  | $ | 5,383,127 |  |  | $ | 1,057,218 |  |  | $ | 14,333,052 |  |  | $ | 3,302,948 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Depreciation and amortization |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Retail and Online |  | $ | 329,416 |  |  | $ | 65,404 |  |  | $ | 884,522 |  |  | $ | 201,647 |  |  
    | Manufacturing |  |  | 760,125 |  |  |  | 496,591 |  |  |  | 2,228,264 |  |  |  | 1,421,366 |  |  
    | Services |  |  | – |  |  |  | – |  |  |  | – |  |  |  | – |  |  
    |  |  | $ | 1,089,541 |  |  | $ | 561,995 |  |  | $ | 3,112,786 |  |  | $ | 1,623,013 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Interest expenses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Retail and Online |  | $ | 1,600,589 |  |  | $ | 10,346 |  |  | $ | 4,283,015 |  |  | $ | 121,319 |  |  
    | Manufacturing |  |  | 527,201 |  |  |  | 259,661 |  |  |  | 1,329,304 |  |  |  | 829,157 |  |  
    | Services |  |  | – |  |  |  | – |  |  |  | – |  |  |  | – |  |  
    |  |  | $ | 2,127,790 |  |  | $ | 270,007 |  |  | $ | 5,612,319 |  |  | $ | 950,476 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Net income (loss) before provision for income taxes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Retail and Online |  | $ | 797,504 |  |  | $ | (1,573,841 | ) |  | $ | 2,842,206 |  |  | $ | (3,319,139 | ) |  
    | Manufacturing |  |  | 2,175,749 |  |  |  | 2,457,201 |  |  |  | 5,363,455 |  |  |  | 5,643,733 |  |  
    | Services |  |  | 294,736 |  |  |  | 230,559 |  |  |  | 712,886 |  |  |  | 722,155 |  |  
    |  |  | $ | 3,267,989 |  |  | $ | 1,113,919 |  |  | $ | 8,918,547 |  |  | $ | 3,046,749 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    |  |  |  |  |  |  |  |  |  |  |  | As of |  |  |  | As of |  |  
    |  |  |  |  |  |  |  |  |  |  |  | June 30, |  |  |  | September 30, |  |  
    |  |  |  |  |  |  |  |  |  |  |  | 2017 |  |  |  | 2016 |  |  
    | Total assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Retail and Online |  |  |  |  |  |  |  |  |  | $ | 41,070,216 |  |  | $ | 15,053,993 |  |  
    | Manufacturing |  |  |  |  |  |  |  |  |  |  | 49,717,336 |  |  |  | 38,333,437 |  |  
    | Services |  |  |  |  |  |  |  |  |  |  | 34,934,464 |  |  |  | 79,970 |  |  
    |  |  |  |  |  |  |  |  |  |  | $ | 125,722,016 |  |  | $ | 53,467,400 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Goodwill and intangible assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Retail and Online |  |  |  |  |  |  |  |  |  | $ | 41,464,911 |  |  | $ | 1,287,338 |  |  
    | Manufacturing |  |  |  |  |  |  |  |  |  |  | 380,501 |  |  |  | 402,452 |  |  
    | Services |  |  |  |  |  |  |  |  |  |  | – |  |  |  | – |  |  
    |  |  |  |  |  |  |  |  |  |  | $ | 41,845,412 |  |  | $ | 1,689,790 |  |  |