Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Summary of Effects of Reclassifications from Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Amortization of pension and other postretirement benefit plan items:
Net of tax	$ 877	$ 1,111	$ 2,568	$ 3,416
Pension and Other Postretirement Benefit Plans [Member] | Reclassified from Accumulated Other Comprehensive Income (Loss) [Member]
Amortization of pension and other postretirement benefit plan items:
Actuarial losses			4,282
Prior service credit			(107)
Total before tax			4,175
Tax benefit			(1,607)
Net of tax			$ 2,568