Long-Term Debt - Summary of long term debt (Parentheticals) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Description of rate basis	Libor
Percentage of floating interest rate payable	1.40%
Term loan payable to a financial institution; Interest rate option of bank prime or Libor plus 1.4% (3.7492% as of December 31, 2018), monthly prinicipal payments of $21,833 through 2021 with a balloon payment of $786,000 due December 1, 2021
Debt Instrument [Line Items]
Description of rate basis	Libor
Percentage of floating interest rate payable	1.40%
Percentage of fixed interest rate payable	3.7492%
Frequency of principal payments	monthly
Monthly principal payments	$ 21,833
Balloon payment due December 1, 2021	$ 786,000
Term loan payable to a financial institution; Interest rate option of bank prime or Libor plus 1.4% (3.7492% as of December 31, 2018), monthly prinicipal payments of $23,810 through December 1, 2021
Debt Instrument [Line Items]
Description of rate basis	Libor
Percentage of floating interest rate payable	1.40%
Percentage of fixed interest rate payable	3.7492%
Frequency of principal payments	monthly
Monthly principal payments	$ 23,810
Lease line of credit for equipment; Interest rate fixed for term of each funding based upon the Lender's lease pricing at time of funding. (Interest rate/factor 1.822758% - 1.869304% at time of funding) | Minimum
Debt Instrument [Line Items]
Percentage of floating interest rate payable	1.82276%
Lease line of credit for equipment; Interest rate fixed for term of each funding based upon the Lender's lease pricing at time of funding. (Interest rate/factor 1.822758% - 1.869304% at time of funding) | Maximum
Debt Instrument [Line Items]
Percentage of floating interest rate payable	1.8693%