Retirement Plans - Funded Status of the Defined Benefit Plans (Detail) - USD ($) $ in Thousands		12 Months Ended
	Sep. 30, 2015	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Change in benefit obligation:
Actuarial loss (gain)		$ 74,000	$ (73,000)
Curtailment	$ (73,000)
Change in plan assets:
Fair value of plan assets at beginning of period		742,341
Fair value of plan assets at end of period		799,166	742,341
Amounts recognized in the consolidated balance sheets consist of the following:
Accrued benefit obligation—noncurrent		(172,895)	(126,448)
Pension Benefits [Member]
Change in benefit obligation:
Benefit obligation at beginning of period		862,886	970,469	$ 733,752
Service cost		3,849	32,582	27,729
Interest cost		40,459	39,628	37,468
Actuarial loss (gain)		73,855	(73,282)	199,807
Curtailment			(73,191)
Prior year correction		21,917
Settlements		(16,002)	(15,287)	(11,517)
Special termination benefit			422
Benefit disbursements		(20,730)	(18,455)	(16,770)
Benefit obligation at end of period		966,234	862,886	970,469
Change in plan assets:
Fair value of plan assets at beginning of period		742,341	749,166	641,749
Return on plan assets		57,855	(21,572)	86,857
Employer contribution		35,702	48,489	48,847
Settlements		(16,002)	(15,287)	(11,517)
Benefit disbursements		(20,730)	(18,455)	(16,770)
Fair value of plan assets at end of period		799,166	742,341	749,166
Net amount recognized		(167,068)	(120,545)	(221,303)
Amounts recognized in the consolidated balance sheets consist of the following:
Accrued benefit obligation—current		(549)	(546)	(453)
Accrued benefit obligation—noncurrent		(166,519)	(119,999)	(220,850)
Net amount recognized in the consolidated balance sheets		(167,068)	(120,545)	(221,303)
Amounts recognized in Accumulated other comprehensive loss consist of the following:
Prior service cost		281	438	634
Net gain (loss)		(221,146)	(147,675)	(231,446)
Net gain (loss) recognized in Accumulated other comprehensive loss		(221,427)	(148,113)	(232,080)
Accumulated benefit obligation		963,008	854,858	888,937
Amounts expected to be amortized from Accumulated other comprehensive loss in the next fiscal year:
Net loss (gain)		3,998
Prior service cost		138
Net expected to be amortized		4,136
Other Postretirement Plans [Member]
Change in benefit obligation:
Benefit obligation at beginning of period		6,974	6,789	9,375
Service cost		37	37	79
Interest cost		296	264	318
Employee contributions		204	209	215
Actuarial loss (gain)		174	(1,035)	986
Curtailment				(3,612)
Plan amendment			1,291
Benefit disbursements		(733)	(581)	(572)
Benefit obligation at end of period		6,952	6,974	6,789
Change in plan assets:
Employer contribution		529	372	357
Employee contributions		204	209	215
Benefit disbursements		(733)	(581)	(572)
Net amount recognized		(6,952)	(6,974)	(6,789)
Amounts recognized in the consolidated balance sheets consist of the following:
Accrued benefit obligation—current		(576)	(525)	(533)
Accrued benefit obligation—noncurrent		(6,376)	(6,449)	(6,256)
Net amount recognized in the consolidated balance sheets		(6,952)	(6,974)	(6,789)
Amounts recognized in Accumulated other comprehensive loss consist of the following:
Net gain (loss)		825	1,064	1,368
Net gain (loss) recognized in Accumulated other comprehensive loss		825	$ 1,064	$ 1,368
Amounts expected to be amortized from Accumulated other comprehensive loss in the next fiscal year:
Net loss (gain)		(149)
Prior service cost		6
Net expected to be amortized		$ (143)