Note 5 - Long-term Debt (Details Textual) $ in Thousands	3 Months Ended
	Apr. 01, 2018 USD ($)
Interest Rate Swap [Member]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	$ 0
Derivative, Notional Amount	100,000
Interest Rate Swap [Member] | Other Assets [Member]
Derivative Asset, Fair Value, Gross Asset, Total	2,500
Syndicated Facility Agreement [Member]
Long-term Line of Credit, Total	77,600
Letters of Credit Outstanding, Amount	$ 5,700
Long-term Debt, Weighted Average Interest Rate, at Point in Time	3.00%
Syndicated Facility Agreement [Member] | Term Loan A [Member]
Long-term Debt, Total	$ 166,300
Debt Instrument, Periodic Payment, Total	3,750
Other Line Of Credit [Member]
Long-term Line of Credit, Total	0
Line of Credit Facility, Maximum Borrowing Capacity	$ 9,900
Other Line Of Credit [Member] | Minimum [Member]
Line of Credit Facility, Interest Rate During Period	2.50%
Other Line Of Credit [Member] | Maximum [Member]
Line of Credit Facility, Interest Rate During Period	6.50%