Long Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Unamortized Debt Issuance Expense	$ 467	$ 622
Total long-term debt	486,443	498,490
Current portion of long-term debt	14,699	10,202
Long-term debt	471,744	488,288
Revolving Line of Credit [Member]
Debt Instrument [Line Items]
Total long-term debt	327,000	329,000
Term Loan Facility [Member]
Debt Instrument [Line Items]
Total long-term debt	157,033	165,628
Mortgages Notes [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 2,410	$ 3,862