Employee Benefit Plans (Details) $ in Thousands		12 Months Ended
		Dec. 30, 2017 USD ($) plan	Dec. 31, 2016 USD ($)	Jan. 02, 2016 USD ($)
Fair Value Measurement [Domain]
Change in plan assets:
Fair value of plan assets at beginning of period		$ 134,909
Fair value of plan assets at end of period		150,517	$ 134,909
Fair Value Measurement [Domain] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		85,936
Fair value of plan assets at end of period		97,425	85,936
Fair Value Measurement [Domain] | Fair Value, Inputs, Level 2 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		7,887
Fair value of plan assets at end of period		6,501	7,887
Fair Value Measurement [Domain] | Fair Value, Inputs, Level 3 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		2,783
Fair value of plan assets at end of period		3,375	2,783
Projected benefit obligation at beginning of period		189,290	182,276
Service cost		3,043	2,549	$ 6,638
Interest cost		6,711	6,950	10,536
Employee contributions		436	439
Employee contributions		436	439
Plan amendments		(8)	101
Actuarial loss/(gain)		8,051	7,905
Benefits paid		(7,063)	(7,146)
Effect of curtailment		0	(1,286)
Effect of settlement		(884)	(953)
Other		5,152	(1,545)
Projected benefit obligation at end of period		204,728	189,290	182,276
Fair value of plan assets at beginning of period		134,909	127,970
Actual return on plan assets		19,030	10,138
Employer contributions		4,214	5,250
Benefits paid		7,063	7,146
Effect of settlement		(884)	(953)
Defined Benefit Plan, Plan Assets, Divestiture		(2,262)	0
Other		2,137	(789)
Fair value of plan assets at end of period		150,517	134,909	127,970
Funded status		(54,211)	(54,381)
Amounts recognized in the consolidated balance sheets consist of:
Current liability		(1,440)	(1,229)
Noncurrent liability		(52,771)	(53,152)
Net amount recognized		(54,211)	(54,381)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss		43,651	52,525
Prior service cost/(credit)		371	417
Net amount recognized	[1]	44,022	52,942
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax		16,300	19,400
Accumulated benefit obligation		192,192	181,340
Net pension cost includes the following components:
Service cost		3,043	2,549	6,638
Interest cost		6,711	6,950	10,536
Expected return on plan assets		(7,181)	(7,552)	(12,229)
Net amortization and deferral		4,821	4,668	5,034
Curtailment		0	(1,285)	(1,181)
Settlement		42	(114)	(2,353)
Net pension cost		7,436	5,216	6,445
Amounts recognized in accumulated other comprehensive income (loss):
Amortization of actuarial loss		2,985	2,846	3,115
Actuarial (loss)/gain recognized		2,763	(3,861)	(2,323)
Amortization of settlement		27	(69)	3,823
Amortization of prior service costs		24	24	(31)
Amortization of curtailment				(853)
Other		30	44	471
Pension adjustments		5,829	$ (1,016)	$ 4,202
Estimated amount that will be amortized from accumulated other comprehensive loss into net periodic pension cost in fiscal 2012:
Net actuarial loss		3,556
Prior service cost		35
Total		$ 3,591
Weighted average assumptions used to determine benefit obligations:
Discount rate		3.40%	3.81%	4.13%
Rate of compensation increase		0.38%	0.38%	0.31%
Weighted average assumptions used to determine net periodic benefit cost for the employee benefit pension plans:
Discount rate		3.49%	3.55%	3.47%
Rate of increase in future compensation levels		0.43%	0.84%	0.38%
Expected long-term rate of return on assets		6.17%	6.52%	6.62%
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2018		$ 9,780
2019		9,790
2020		9,641
2021		11,385
2022		11,098
Years 2023 – 2027		61,843
Multiemployer Plans [Abstract]
Contributions		$ 3,472	$ 3,373	$ 3,231
Number Of Multiemployer Plans, Withdrawal Obligation | plan		2
Multiemployer Plans, Withdrawal Obligation		$ 1,700
Fair Value, Inputs, Level 3 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		2,783	2,320
Fair value of plan assets at end of period		3,375	2,783	2,320
Western Conference Of Teamsters Pension Plan [Member]
Multiemployer Plans [Abstract]
Contributions	[2]	1,524	1,456	1,387
Central States, Southeast and Southwest Areas Pension Plan [Member]
Multiemployer Plans [Abstract]
Contributions	[3],[4]	968	934	858
Other Multiemployer Plans [Member]
Multiemployer Plans [Abstract]
Contributions		$ 980	983	$ 986
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plan, Contributions To Individual Plan, Percent		5.00%
Estimate of Fair Value Measurement [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		$ 96,606
Fair value of plan assets at end of period		107,301	96,606
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		85,936
Fair value of plan assets at end of period		97,425	85,936
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		7,887
Fair value of plan assets at end of period		6,501	7,887
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		2,783
Fair value of plan assets at end of period		3,375	2,783
Estimate of Fair Value Measurement [Member] | Fixed Income, Long Term [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		17,408
Fair value of plan assets at end of period		23,231	17,408
Estimate of Fair Value Measurement [Member] | Fixed Income, Long Term [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		17,408
Fair value of plan assets at end of period		23,231	17,408
Estimate of Fair Value Measurement [Member] | Fixed Income, Long Term [Member] | Fair Value, Inputs, Level 2 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Fixed Income, Long Term [Member] | Fair Value, Inputs, Level 3 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Fixed Income, Short Term [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		2,825
Fair value of plan assets at end of period		1,869	2,825
Estimate of Fair Value Measurement [Member] | Fixed Income, Short Term [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		2,825
Fair value of plan assets at end of period		1,869	2,825
Estimate of Fair Value Measurement [Member] | Fixed Income, Short Term [Member] | Fair Value, Inputs, Level 2 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Fixed Income, Short Term [Member] | Fair Value, Inputs, Level 3 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Equity Securities, Domestic [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		41,300
Fair value of plan assets at end of period		44,173	41,300
Estimate of Fair Value Measurement [Member] | Equity Securities, Domestic [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		41,300
Fair value of plan assets at end of period		44,173	41,300
Estimate of Fair Value Measurement [Member] | Equity Securities, Domestic [Member] | Fair Value, Inputs, Level 2 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Equity Securities, Domestic [Member] | Fair Value, Inputs, Level 3 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Equity Securities, International [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		24,403
Fair value of plan assets at end of period		28,152	24,403
Estimate of Fair Value Measurement [Member] | Equity Securities, International [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		24,403
Fair value of plan assets at end of period		28,152	24,403
Estimate of Fair Value Measurement [Member] | Equity Securities, International [Member] | Fair Value, Inputs, Level 2 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Equity Securities, International [Member] | Fair Value, Inputs, Level 3 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Insurance Contracts [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		10,670
Fair value of plan assets at end of period		9,876	10,670
Estimate of Fair Value Measurement [Member] | Insurance Contracts [Member] | Fair Value, Inputs, Level 1 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		0
Fair value of plan assets at end of period		0	0
Estimate of Fair Value Measurement [Member] | Insurance Contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		7,887
Fair value of plan assets at end of period		6,501	7,887
Estimate of Fair Value Measurement [Member] | Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		2,783
Fair value of plan assets at end of period		3,375	2,783
Portion at Other than Fair Value Measurement [Member]
Change in plan assets:
Fair value of plan assets at beginning of period		38,303
Fair value of plan assets at end of period		$ 43,216	$ 38,303

[1] Amounts do not include deferred taxes of $16.3 million and $19.4 million at December 30, 2017 and December 31, 2016, respectively.

[2] The Company has several plants that participate in the Western Conference of Teamsters Pension Plan under collective bargaining agreements that require minimum funding contributions. Certain of these agreements have expired and are being renegotiated with others having expiration dates through April 1, 2020.

[3] In July 2005 this plan received a 10 year extension from the IRS for amortizing unfunded liabilities.

[4] The Company has several processing plants that participate in the Central States, Southeast and Southwest Areas Pension Plan under collective bargaining agreements that require minimum funding contributions. Certain of these agreements have expired and are being renegotiated with others having expiration dates through August 6, 2018.