Earnings Per Share - Computation of Basic and Diluted Earnings Per Common Share (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Earnings Per Share [Abstract]
Weighted-average common shares outstanding (in shares)	54.3	55.0	54.4	55.2
Effect of dilutive securities (in shares)	0.5	0.7	0.5	0.8
Weighted-average common shares outstanding, diluted (in shares)	54.8	55.7	54.9	56.0