Property, Plant and Equipment, Net (Narrative) (Details) |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 04, 2015
ft²
item
|
Dec. 31, 2015
USD ($)
|
Dec. 31, 2014
USD ($)
|
|
| Depreciation expense | $ | $ 1,461,353 | $ 1,471,832 | |
| Fitchburg, Massachusetts [Member] | |||
| Number of unoccupied buildings with letter of intent to sale | item | 2 | ||
| Area of unoccupied buildings | ft² | 52,000 | ||