Retirement Plans (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
Defined Benefit Plan Disclosure
Actuarial gain			$ 4,991	$ 4,203
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure
Service cost	685	656	2,054	2,092
Interest cost	4,111	4,380	12,333	13,164
Expected return on plan assets	(4,090)	(3,902)	(12,269)	(11,720)
Amortization of unrecognized prior service benefit	58	155	174	466
Settlement loss				680
Actuarial gain	1,937		5,083	4,279
Total net periodic pension cost	2,701	1,289	7,375	8,961
Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure
Service cost	17	15	50	45
Interest cost	109	135	328	405
Amortization of unrecognized prior service benefit	(150)	(150)	(449)	(449)
Actuarial gain			(92)	(76)
Total net periodic pension cost	$ (24)		$ (163)	$ (75)