Employee Benefit Plans - Components of Net Periodic Benefit Cost (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Sep. 30, 2012	Oct. 02, 2011
Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 6,391	$ 5,236	$ 17,804	$ 15,353
Interest cost	17,906	18,125	52,430	53,480
Expected return on plan assets	(20,890)	(20,977)	(62,889)	(63,359)
Amortization of net transition obligation	115	116	344	353
Amortization of prior service cost	139	144	308	215
Amortization of net actuarial loss	10,525	6,414	28,722	18,183
Net periodic benefit cost	14,186	9,058	36,719	24,225
Retiree Health and Life Insurance Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	131	164	615	766
Interest cost	154	342	841	1,193
Expected return on plan assets	(391)	(383)	(1,131)	(1,090)
Amortization of prior service cost	(1,619)	(1,998)	(4,872)	(5,940)
Amortization of net actuarial loss	(403)	2	(2)	699
Net periodic benefit cost	$ (2,128)	$ (1,873)	$ (4,549)	$ (4,372)