Note 9 - Earnings Per Share (Details) - Computation of Basic and Diluted Earnings Per Share under the Two-class Method (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Computation of Basic and Diluted Earnings Per Share under the Two-class Method [Abstract]
Net income as reported	$ 11,488	$ 17,563
Less: Distributed earnings available to participating securities	(9)	(6)
Less: Undistributed earnings available to participating securities	(7)	(43)
Numerator for basic earnings per share —
Undistributed and distributed earnings available to common shareholders	11,472	17,514
Add: Undistributed earnings allocated to participating securities	7	44
Less: Undistributed earnings reallocated to participating securities	(6)	(44)
Numerator for diluted earnings per share —
Undistributed and distributed earnings available to common shareholders	$ 11,473	$ 17,514
Denominator for basic earnings per share —
Weighted-average shares (in Shares)	22,095	21,608
Effect of dilutive securities:
Common stock equivalents (in Shares)	271	321
Denominator for diluted earnings per share —
Adjusted for weighted-average shares & assumed conversions (in Shares)	22,366	21,929
Basic earnings per share (in Dollars per share)	$ 0.52	$ 0.81
Diluted earnings per share (in Dollars per share)	$ 0.51	$ 0.80