Summary Of Significant Accounting Policies (Reconciliation Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2015	Oct. 04, 2015	Jul. 05, 2015	Apr. 05, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Basic EPS, Net Income	$ (2,002)	$ 4,418	$ 3,813	$ 3,872	$ 7,156	$ (8,078)	$ 1,872	$ 8,912	$ 10,101	$ 9,863	$ 50,386
Dilutive securities, principally common stock options, Net Income
Diluted EPS, Net Income									$ 10,101	$ 9,863	$ 50,386
Basic EPS, Shares									16,418	16,850	17,660
Dilutive securities, principally common stock options, Shares									118	63	108
Diluted EPS, Shares									16,536	16,913	17,768
Basic EPS, Per Share Amount	$ (0.12)	$ 0.27	$ 0.23	$ 0.24	$ 0.44	$ (0.49)	$ 0.11	$ 0.50	$ 0.62	$ 0.59	$ 2.85
Dilutive securities, principally common stock options, Per Share Amount									(0.01)	(0.01)	(0.01)
Diluted EPS, Per Share Amount	$ (0.12)	$ 0.27	$ 0.23	$ 0.23	$ 0.43	$ (0.49)	$ 0.11	$ 0.50	$ 0.61	$ 0.58	$ 2.84