Long-Term Debt and Credit Facility - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Subtotal	$ 319,625	$ 314,219
Less – Current maturities of long-term debt	30,625	29,469
Less – Unamortized loan costs	2,583	2,747
Total	286,417	282,003
Term Note
Debt Instrument [Line Items]
Term note, due February 27, 2023, annualized rates of 4.52% and 4.59%, respectively	$ 275,625	$ 282,188
Current effective interest rate	4.52%	4.59%
Line of Credit
Debt Instrument [Line Items]
Line of credit, 4.49% and 4.45%, respectively	$ 44,000	$ 31,000
Current effective interest rate	4.49%	4.45%
Other notes
Debt Instrument [Line Items]
Other notes with interest rates from 3.3% to 7.8%	$ 0	$ 1,031
Other notes | Minimum
Debt Instrument [Line Items]
Current annualized interest rate	3.30%
Other notes | Maximum
Debt Instrument [Line Items]
Current annualized interest rate	7.80%