Pension and Other Post-retirement Benefits (Detail) - The aggregate costs of retirement benefits (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Pension Plans, Defined Benefit [Member]
Interest cost	$ 2,043	$ 2,121	$ 2,211
Expected return on plan assets	(2,014)	(1,877)	(1,854)
Amortization of prior service credits
Recognized actuarial loss (gain)	852	1,576	1,401
Net periodic benefit cost (gain)	881	1,820	1,758
Other Benefits [Member]
Interest cost	29	35	39
Expected return on plan assets
Amortization of prior service credits		(21)	(30)
Recognized actuarial loss (gain)	(23)	(16)	(6)
Net periodic benefit cost (gain)	$ 6	$ (2)	$ 3