Long-term Debt, Line of Credit and Derivatives - Obligations under Debt Arrangements (Details) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	May 31, 2019	Mar. 31, 2019	Jul. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Amortization of debt issuance costs				$ 453	$ 725	$ 1,269
Net Value, current				3,668	2,946
Net Value, long-term				68,029	76,119
Total debt				$ 71,697	79,065
Line of Credit
Debt Instrument [Line Items]
Weighted average interest rate				5.41%
Principal current				$ 3,750	3,000
Principal, long-term				69,540	77,500
Principal				73,290	80,500
Deferred Finance Costs, current				(82)	(54)
Deferred Issuance Costs, long-term				(1,511)	(1,381)
Debt Issuance Costs, Net, Total				(1,593)	(1,435)
Revolving Credit Facility
Debt Instrument [Line Items]
Net Value, long-term				35,218	21,787
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity				50,000
Debt issuance expense	$ 400
Principal, long-term				36,000	22,000
Deferred Issuance Costs, long-term				(782)	(213)
Term Loan
Debt Instrument [Line Items]
Net Value, current				3,668	2,946
Net Value, long-term				32,811	54,332
Term Loan | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					60,000
Principal current				3,750	3,000
Principal, long-term				33,540	55,500
Principal				37,290
Deferred Finance Costs, current				(82)	(54)
Deferred Issuance Costs, long-term				(729)	$ (1,168)
Fourth, Fifth And Sixth Amendments To Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Debt Issuance Costs, Net, Total				$ (900)
Fourth Amendment to Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Debt issuance cost			$ 900
Fifth Amendment To Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Debt issuance cost		$ 600
Sixth Amendment To Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Debt issuance cost	$ 900