Note 9 - Debt (Details Textual) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Long-term Debt, Total	$ 112,300		$ 112,300		$ 114,200
Proceeds from Lines of Credit, Total			12,000	$ 7,500
Credit and Security Agreement with KeyBank [Member]
Debt Issuance Costs, Net, Total	$ 1,400		$ 1,400		$ 1,800
Debt, Weighted Average Interest Rate	3.81%		3.81%		4.31%
Interest Expense, Debt, Total	$ 1,300	$ 1,400	$ 4,100	$ 3,900
Credit and Security Agreement with KeyBank [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	75,000		75,000
Long-term Line of Credit, Total	0		0		$ 0
Proceeds from Lines of Credit, Total			12,000
Credit and Security Agreement with KeyBank [Member] \| Term Loan [Member]
Long-term Debt, Total	$ 113,800		$ 113,800		$ 116,000

Weighted average interest rate of debt outstanding.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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