Short-Term and Long-Term Debt, Including Finance Leases - Long-term debt instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Finance lease obligations	$ 77
Finance lease obligations		$ 94
Total long-term debt and finance leases	176,954	190,410
Less: portion of Credit Facility classified as short-term	(28,531)	(23,195)
Less: current installments of finance leases	(15)	(89)
Long-term debt and finance leases, less current installments	148,408	167,126
Credit Facility
Debt Instrument [Line Items]
Credit Facility	176,877	190,316
Less: portion of Credit Facility classified as short-term	$ (28,531)	$ (23,195)

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Present value of lessee's discounted obligation for lease payments from finance lease.

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