Components of Net Periodic Benefit Costs (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
Pension Obligations
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,435	$ 1,473	$ 4,299	$ 4,187
Interest cost	3,018	2,844	9,065	8,521
Expected return on plan assets	(3,171)	(2,807)	(9,504)	(8,570)
Amortization of prior service credit	(20)	(56)	(59)	(128)
Net loss recognition	1,493	1,447	4,475	4,535
Net periodic benefit cost	2,755	2,901	8,276	8,545
Other Postretirement Obligations
Defined Benefit Plan Disclosure [Line Items]
Service cost	32	32	94	113
Interest cost	580	577	1,713	1,931
Expected return on plan assets
Amortization of prior service credit	(29)	(54)	(87)	(173)
Net loss recognition	252	124	738	354
Net periodic benefit cost	$ 835	$ 679	$ 2,458	$ 2,225