Reconciliation of Average Number of Common Shares Outstanding to Average Number of Diluted Shares Outstanding (Detail) - shares	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jun. 25, 2016	Jul. 01, 2017	Jun. 25, 2016
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Average number of common shares outstanding	41,935,000	42,235,000	41,907,000	42,315,000
Incremental shares from assumed exercises of stock options	75,000	122,000	97,000	109,000
Average number of common shares and common share equivalents outstanding	42,010,000	42,357,000	42,004,000	42,424,000