Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 26, 2018		Sep. 26, 2018		Jun. 27, 2018		Mar. 28, 2018		Dec. 27, 2017		Sep. 27, 2017		Jun. 28, 2017		Mar. 29, 2017		Dec. 26, 2018	Dec. 27, 2017	Dec. 28, 2016
Earnings Per Share [Abstract]
Net income	$ 11,503		$ 10,805		$ 11,626		$ 9,759		$ 13,147		$ 9,325		$ 8,749		$ 8,373		$ 43,693	$ 39,594	$ 19,402
Weighted average shares outstanding - basic (in shares)																	63,364	68,077	75,325
Effect of dilutive share-based compensation awards																	2,198	2,326	1,881
Weighted average shares outstanding - diluted (in shares)																	65,562	70,403	77,206
Basic net income per share	$ 0.19	[1]	$ 0.17	[1]	$ 0.18	[1]	$ 0.15	[1]	$ 0.20	[2]	$ 0.14	[2]	$ 0.13	[2]	$ 0.12	[2]	$ 0.69	$ 0.58	$ 0.26
Diluted net income per share	$ 0.18	[1]	$ 0.16	[1]	$ 0.18	[1]	$ 0.15	[1]	$ 0.19	[2]	$ 0.13	[2]	$ 0.12	[2]	$ 0.11	[2]	$ 0.67	$ 0.56	$ 0.25
Anti-dilutive share-based compensation awards (in shares)																	0	606	0

[1] Per share amounts do not necessarily sum to the total year amounts due to changes in shares outstanding and rounding

[2] Per share amounts do not necessarily sum to the total year amounts due to changes in shares outstanding and rounding.