Long-term Debt and Line of Credit Narrative (Details) - USD ($)		12 Months Ended
	Jul. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 05, 2015
Debt Instrument [Line Items]
Principal current		$ 3,000,000	$ 23,500,000
Principal, long-term		77,500,000	65,250,000
Principal		80,500,000	88,750,000
Deferred Finance Costs, current		(54,000)	(744,000)
Deferred Issuance Costs, long-term		(1,381,000)	(2,065,000)
Deferred Issuance Costs		(1,435,000)	(2,809,000)
Net Value, current		2,946,000	22,756,000
Long-term Debt, Excluding Current Maturities		76,119,000	63,185,000
Total debt		79,065,000	85,941,000
Hedging Liabilities, Noncurrent		52,000	26,000
Debt issuance cost		900,000
Amortization of debt issuance costs	$ 2,200,000	725,000	1,269,000	$ 1,225,000
Debt issuance expense		$ 700,000
Line of Credit
Debt Instrument [Line Items]
Debt, weighted average interest rate		4.63%
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Principal current		$ 0	10,000,000
Principal, long-term		22,000,000	0
Deferred Finance Costs, current		0	(317,000)
Deferred Issuance Costs, long-term		(213,000)	0
Net Value, current		0	9,683,000
Long-term Debt, Excluding Current Maturities		21,787,000	0
Line of credit facility, maximum borrowing capacity		$ 65,000,000.0			$ 100,000,000.0
Stated interest rate		4.63%
Term Loan | Line of Credit
Debt Instrument [Line Items]
Total debt		$ 58,500,000
Line of credit facility, maximum borrowing capacity		60,000,000.0
Term loan-current | Loans Payable
Debt Instrument [Line Items]
Principal current		3,000,000	13,500,000
Deferred Finance Costs, current		(54,000)	(427,000)
Net Value, current		2,946,000	13,073,000
Term loan-long-term | Loans Payable
Debt Instrument [Line Items]
Principal, long-term		55,500,000	65,250,000
Deferred Issuance Costs, long-term		(1,168,000)	(2,065,000)
Long-term Debt, Excluding Current Maturities		$ 54,332,000	$ 63,185,000