Method save does not exist in laravel

Here is my controller

public function update(Request $request)
{
    $ids = $request->input('id');
    $success_output = '';
      $companies = companies::find($ids);
      companies::where('id',$ids);
      $this->validate($request,
        ['company_name' => 'required',
            'status' => 'required',
        ]);
      $companies->company_name = $request->input('company_name');
      $companies->status = $request->input('status');
      $companies->save();

      $success_output = '<div class="alert alert-success">Data Inserted</div>';

      return redirect('/companies')->with('success','updated');
}

where is the problem? in console it returns that the "method save does not exist." couldn't find a solution

via Chebli Mohamed