Note 5 - Shareholders' Equity - Dividends Declared (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014
Dividend Declared 1 [Member]
Declaration date	Feb. 13, 2015
Dividend per share (in dollars per share)	$ 0.06
Record date	Feb. 26, 2015
Total amount	$ 2,082
Payment date	Mar. 12, 2015
Dividends Declared 2 [Member]
Declaration date	Apr. 21, 2015
Dividend per share (in dollars per share)	$ 0.06
Record date	May 14, 2015
Total amount	$ 2,090
Payment date	May 28, 2015
Dividends Declared 3 [Member]
Declaration date		Feb. 21, 2014
Dividend per share (in dollars per share)		$ 0.05
Record date		Mar. 13, 2014
Total amount		$ 1,798
Payment date		Mar. 27, 2014
Dividends Declared 4 [Member]
Declaration date		Apr. 22, 2014
Dividend per share (in dollars per share)		$ 0.05
Record date		May 15, 2014
Total amount		$ 1,798
Payment date		May 29, 2014