Earnings Per Share - Schedule of Computation of Basic Earnings per Share and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Numerator:
Net income	$ 21,967	$ 27,008	$ 28,437	$ 29,187	$ 28,701	$ 26,695	$ 25,982	$ 24,671	$ 106,599	$ 106,049	$ 92,329
Denominator:
Weighted average basic shares outstanding									33,964	34,516	35,466
Effect of compensation awards									88	82	72
Weighted average diluted shares outstanding									34,052	34,598	35,538
Earnings Per Share:
Basic									$ 3.14	$ 3.07	$ 2.60
Diluted	$ 0.65	$ 0.80	$ 0.83	$ 0.85	$ 0.83	$ 0.77	$ 0.75	$ 0.71	$ 3.13	$ 3.07	$ 2.60