Note 7 - Revolving Credit Agreement (Details Textual) - PNC Bank [Member] - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Mar. 27, 2016
Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 20,000
Line of Credit Facility Maximum Borrowing Capacity May Be Increased to	$ 35,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.375%
Long-term Line of Credit		$ 1,156
Letters of Credit Outstanding, Amount	$ 0
Letter of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity	1,000
Line of Credit Facility, Remaining Borrowing Capacity	10,789
Long-term Line of Credit	$ 0