| Schedule of goodwill and intangible assets | 
 Goodwill and intangible assets consisted of the following: 
  
    |   | 
      | 
      | 
      | 
    December 31, 2018 | 
 
    |   | 
      | 
    
Estimated life 
in years
 | 
      | 
    Gross amount | 
      | 
    
Accumulated  
Amortization
 | 
      | 
    Net | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Intangible assets not subject to amortization | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Goodwill | 
      | 
      | 
    Indefinite | 
      | 
      | 
    $ | 
    3,015,700 | 
      | 
      | 
    $ | 
    —   | 
      | 
      | 
    $ | 
    3,015,700 | 
      | 
 
    | Trademarks | 
      | 
      | 
    Indefinite | 
      | 
      | 
      | 
    294,268 | 
      | 
      | 
      | 
    —   | 
      | 
      | 
      | 
    294,268 | 
      | 
 
    |     Total intangible assets not subject to amortization | 
      | 
      | 
      | 
      | 
      | 
      | 
    3,309,968 | 
      | 
      | 
      | 
    —   | 
      | 
      | 
      | 
    3,309,968 | 
      | 
 
    | Intangible assets subject to amortization | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Customer lists | 
      | 
      | 
    5 - 15 | 
      | 
      | 
      | 
    897,274 | 
      | 
      | 
      | 
    897,274 | 
      | 
      | 
      | 
    —   | 
      | 
 
    | ABC acquired contracts | 
      | 
      | 
    5 | 
      | 
      | 
      | 
    310,000 | 
      | 
      | 
      | 
    134,333 | 
      | 
      | 
      | 
    175,667 | 
      | 
 
    | SIAS acquired contracts | 
      | 
      | 
    5 | 
      | 
      | 
      | 
    660,000 | 
      | 
      | 
      | 
    286,000 | 
      | 
      | 
      | 
    374,000 | 
      | 
 
    | Non-compete agreements | 
      | 
      | 
    4 | 
      | 
      | 
      | 
    272,147 | 
      | 
      | 
      | 
    269,369 | 
      | 
      | 
      | 
    2,778 | 
      | 
 
    | Total intangible assets subject to amortization | 
      | 
      | 
      | 
      | 
      | 
      | 
    2,139,421 | 
      | 
      | 
      | 
    1,586,976 | 
      | 
      | 
      | 
    552,445 | 
      | 
 
    | Total Goodwill and Intangible Assets | 
      | 
      | 
      | 
      | 
      | 
    $ | 
    5,449,389 | 
      | 
      | 
    $ | 
    1,586,976 | 
      | 
      | 
    $ | 
    3,862,413 | 
      | 
 
 
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