Funded Status and Amounts Recognized in Consolidated Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Participant contributions	$ 400	$ 400	$ 400
Fair value of plan assets at beginning of year	330,085
Actual return on plan assets	41,900	100	27,000
Participant contributions	400	400	400
Fair value of plan assets at end of year	365,671	330,085
Fair value of plan assets	365,671	330,085
Current liability	(1,288)	(1,335)
Noncurrent liability	(159,158)	(155,263)
Net Periodic Pension Cost
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of year	472,793	341,073
Service cost	610	478	388
Interest cost	21,670	20,923	18,666
Actuarial loss	44,447	42,370
Acquisitions		89,638
Settlements		(768)
Benefits paid	(24,884)	(20,921)	(16,294)
Benefit obligation at end of year	514,636	472,793	341,073
Fair value of plan assets at beginning of year	330,085	277,800
Actual return on plan assets	41,891	67
Employer contribution	18,579	13,314
Acquisitions		60,593
Settlements		(768)
Benefits paid	(24,884)	(20,921)	(16,294)
Fair value of plan assets at end of year	365,671	330,085	277,800
Fair value of plan assets	365,671	330,085	277,800
Benefit obligations	514,636	472,793	341,073
Funded status and amount recognized at end of year	(148,965)	(142,708)
Current liability	(421)	(428)
Noncurrent liability	(148,544)	(142,280)
Amount recognized at end of year	(148,965)	(142,708)
Net actuarial (gain) loss before taxes	184,528	160,756
Accumulated benefit obligation at end of year	513,396	471,673
Net Periodic Postretirement Benefit Cost
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of year	13,889	13,824
Service cost	458	426	632
Interest cost	605	687	875
Participant contributions	356	402
Actuarial loss	(2,513)	(195)
Benefits paid	(1,366)	(1,321)
Less federal subsidy on benefits paid	52	66
Benefit obligation at end of year	11,481	13,889	13,824
Employer contribution	1,010	919
Participant contributions	356	402
Benefits paid	(1,366)	(1,321)
Benefit obligations	11,481	13,889	13,824
Funded status and amount recognized at end of year	(11,481)	(13,889)
Current liability	(867)	(907)
Noncurrent liability	(10,614)	(12,982)
Amount recognized at end of year	(11,481)	(13,889)
Net actuarial (gain) loss before taxes	(4,173)	(1,980)
Prior service (credit) cost before taxes	(570)	(828)
Accumulated benefit obligation at end of year	$ (4,743)	$ (2,808)