Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Summary of Effects of Reclassifications from Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jul. 01, 2012	Apr. 01, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Amortization of pension and other postretirement benefit plan items:
Tax benefit									$ (22,315)	$ 38,194	$ (16,791)
Net income	22,508	29,068	29,492	22,245	166,603	(38,778)	42,390	24,275	103,313	194,490	114,345
Accumulated Other Comprehensive Income (Loss) Pension and Postretirement Liability [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Amortization of pension and other postretirement benefit plan items:
Actuarial losses									7,320
Prior service credit									(162)
Total before tax									7,158
Tax benefit									(2,624)
Net income									$ 4,534