Retirement Plans - Changes in Company's Assets and Related Obligations for its Pension Plans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Change in projected benefit obligations:
Projected benefit obligations at beginning of the year	$ 269,099	$ 230,114
PLG projected benefit obligations at acquisition date	109,705
Service cost pertaining to benefits earned during the year	7,709	6,499	5,729
Interest cost on projected benefit obligations	15,314	13,326	12,719
Actuarial losses	55,665	30,320
Benefits paid to plan participants	(12,307)	(11,160)
Projected benefit obligations at end of the year	445,185	269,099	230,114
Change in fair value of pension assets:
Fair value of pension assets at beginning of the year	163,123	144,411
PLG fair value of pension assets at acquisition date	71,963
Actual return on plan assets	26,001	(3,857)
Benefits paid to plan participants	(12,307)	(11,160)
Fair value of pension assets at end of the year	277,295	163,123	144,411
Funded status	(167,890)	(105,976)
Amounts recognized in the consolidated balance sheets:
Current liabilities	(2,428)	(2,151)
Non current liabilities	(165,462)	(103,825)
Net amount recognized	(167,890)	(105,976)
Amounts recognized in accumulated other comprehensive loss:
Unrecognized net actuarial loss (amount net of tax: 2012 - $(90,525); 2011 - $(74,272))	(137,910)	(113,789)
Unrecognized prior service cost (amount net of tax: 2012 - $(228); 2011 - $(310))	(350)	(477)
Net amount recognized	(138,260)	(114,266)
Funded status of pension plans and SERP (supplemental):
Funded status of qualified defined benefit plans and SERP	(167,890)	(105,976)
Nonqualified trust assets (cash surrender value of life insurance) recorded in other assets and intended to satisfy the projected benefit obligation of unfunded SERP obligations	46,701	38,203
Net funded status of pension plans and SERP (supplemental)	(121,189)	(67,773)
Pension [Member]
Change in fair value of pension assets:
Company contributions	26,657	31,800
SERP [Member]
Change in fair value of pension assets:
Company contributions	$ 1,858	$ 1,929

The difference between fair value of plan assets at the end of the period and the fair value at the beginning of the period, adjusted for contributions and payments of benefits during the period, and after adjusting for taxes and other expenses, as applicable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Actual Return on Plan Assets (Component of Net Periodic Pension Cost)

-URI http://asc.fasb.org/extlink&oid=6504226

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 87

-Paragraph 264

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph d(iv)(b)(i)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 106

-Paragraph 518

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Actual Return on Plan Assets (Component of Net Periodic Postretirement Benefit Cost)

-URI http://asc.fasb.org/extlink&oid=6504192

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.