Shareholders' Equity Net Income per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income	$ 15,791	$ 25,603	$ (778)	$ 24,461	$ 11,287	$ 25,745	$ 1,416	$ 12,969	$ 65,077	$ 51,417	$ 50,519
Basic weighted-average shares outstanding									41,212,000	46,154,000	51,252,000
Effect of dilutive securities									873,000	748,000	849,000
Diluted weighted-average shares outstanding									42,085,000	46,902,000	52,101,000
Net income per share – basic									$ 1.58	$ 1.11	$ 0.99
Net income per share – diluted	$ 0.39	$ 0.62	$ (0.02)	$ 0.56	$ 0.25	$ 0.56	$ 0.03	$ 0.27	$ 1.55	$ 1.10	$ 0.97
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									400,000	600,000	400,000