Note 2 - Long-term Debt (Details Textual) $ in Thousands				6 Months Ended
	Jan. 22, 2019 USD ($)	May 02, 2018 USD ($)	Feb. 28, 2017 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	May 01, 2018 USD ($)	Mar. 01, 2018 USD ($)
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year				$ 6,000
Long Term Debt Maturities Repayments of Principal in Year Six				1,500
Repayments of Long-term Debt, Total				88,667	$ 56,289
Long-term Debt, Gross				123,666		$ 117,693
Long-term Debt, Maturities, Repayments of Principal in Year Two				6,000
Derivative, Fixed Interest Rate								3.12%
Long-term Debt, Maturities, Repayments of Principal in Year Three				6,000
Long-term Debt, Maturities, Repayments of Principal in Year Four				6,000
Long-term Debt, Maturities, Repayments of Principal in Year Five				6,000
Interest Rate Swap [Member]
Derivative, Notional Amount								$ 18,000
Derivative, Notional Amount, Monthly Reduction Amount								$ 300
Derivative, Swaption Interest Rate							3.05%
Interest Rate Swap [Member] | Other Current Liabilities [Member]
Derivative, Notional Amount		$ 17,500
Derivative Liability, Total		100		200
Credit Agreement [Member] | Term Loan 2 [Member]
Debt Instrument, Face Amount		85,000
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year				8,500
Long Term Debt Maturities Repayments of Principal in Year Six				$ 9,300
Debt Instrument, Interest Rate, Effective Percentage				3.25%
Repayments of Long-term Debt, Total	$ 20,000
Long-term Debt, Gross	$ 65,000
Long-term Debt, Maturities, Repayments of Principal in Year Two				$ 9,300
Long Term Debt Maturities Repayments of Principal in Year Eight				800
Long-term Debt, Maturities, Repayments of Principal in Year Three				9,300
Long-term Debt, Maturities, Repayments of Principal in Year Four				9,300
Long-term Debt, Maturities, Repayments of Principal in Year Five				9,300
Long Term Debt Maturities Repayments of Principal in Year Seven				$ 9,300
Credit Agreement [Member] | Term Loan [Member]
Debt Instrument, Face Amount		$ 42,000
Debt Instrument, Interest Rate, Effective Percentage				3.08%
Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Term Loan 2 [Member]
Debt Instrument, Basis Spread on Variable Rate	0.85%
Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Term Loan [Member]
Debt Instrument, Basis Spread on Variable Rate		0.68%
Amended and Restated Credit Agreement [Member]
Fixed Charge Coverage Ratio	1.25
EBITA Ratio	4
Revolving Credit Facility [Member] | Credit Agreement [Member] | Fifth Third Bank [Member]
Line of Credit Facility, Maximum Borrowing Capacity							$ 35,000
Revolving Credit Facility [Member] | Credit Agreement [Member] | BB&T [Member]
Line of Credit Facility, Maximum Borrowing Capacity		$ 75,000
Add on Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate			0.75%
Amended Credit Agreement [Member] | Term Loan [Member]
Debt Instrument, Face Amount			$ 42,000
Amended Credit Agreement [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Expiration Period			7 years
Line of Credit Facility, Maximum Borrowing Capacity			$ 35,000
Line of Credit Facility, Commitment Fee Percentage			0.10%
Letters of Credit Outstanding, Amount				$ 0