Long-Term Debt (Long Term Debt Maturities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Long-term Debt, Fiscal Year Maturity [Abstract]
2019	$ 28,300
2020	28,300
2021	28,300
2022	28,300
2023	253,300
Thereafter	268,350
Total long-term debt, gross	634,850
Revolving Credit Facility [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
2023	115,000
Total long-term debt, gross	115,000	$ 92,787
Term Loans Member
Long-term Debt, Fiscal Year Maturity [Abstract]
2019	28,300
2020	28,300
2021	28,300
2022	28,300
2023	138,300
Thereafter	268,350
Total long-term debt, gross	$ 519,850