Pension and Other Postretirement Obligations - Components of Net Periodic Benefit Costs (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Pension Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,677	$ 1,435	$ 5,040	$ 4,299
Interest cost	2,924	3,018	8,786	9,065
Expected return on plan assets	(3,396)	(3,171)	(10,193)	(9,504)
Amortization of prior service credit	(8)	(20)	(23)	(59)
Actuarial losses	1,662	1,493	4,995	4,475
Net periodic benefit cost	2,859	2,755	8,605	8,276
Other Postretirement Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	33	32	101	94
Interest cost	517	580	1,600	1,713
Expected return on plan assets
Amortization of prior service credit	(27)	(29)	(82)	(87)
Actuarial losses	278	252	876	738
Net periodic benefit cost	$ 801	$ 835	$ 2,495	$ 2,458