Note 4 - Long-term Debt (Details Textual) $ in Thousands	6 Months Ended
	Jul. 02, 2017 USD ($)
Syndicated Facility Agreement [Member]
Long-term Line of Credit	$ 177,500
Letters of Credit Outstanding, Amount	$ 2,600
Long-term Debt, Weighted Average Interest Rate, at Point in Time	2.60%
Debt Instrument, Periodic Payment	$ 3,750
Revolving Credit Facility [Member]
Long-term Line of Credit	52,900
Other Line Of Credit [Member]
Long-term Line of Credit	0
Line of Credit Facility, Maximum Borrowing Capacity	$ 9,800
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%