Postretirement Plans - Additional Information (Detail)	1 Months Ended			12 Months Ended
	Dec. 31, 2015 USD ($) shares	Dec. 31, 2014 USD ($) shares	Sep. 30, 2014 Employee	Jan. 02, 2016 USD ($)	Jan. 03, 2015 USD ($) shares	Dec. 28, 2013 USD ($)
Pension and Other Postretirement Benefits Disclosure [Line Items]
Number of former employees covered | Employee			2,500
Percentage reduced in plan obligations			10.00%
Settlement loss					$ 15,387,000
Expected pension income for fiscal 2016				$ 6,200,000
Expected long-term rate of return on plan assets				8.00%
Percentage of total plan assets				100.00%	100.00%
Proceeds from shares sold on open market by the plan					$ 19,100,000
Expected company contribution				$ 730,000
Postretirement Benefits, minimum years of service for eligibility				10 years
Postretirement Benefits, minimum age for eligibility				55 years
Contributions by participants				$ 224,000	192,000	$ 400,000
Expense under plans				(5,878,000)	5,341,000	(2,041,000)
Total cost and employer contributions				$ 26,500,000	$ 26,200,000	$ 23,000,000
Minimum
Pension and Other Postretirement Benefits Disclosure [Line Items]
Retiree medical coverage provided				3 years
Percentage of funded under multi employer plans				0.00%
Maximum
Pension and Other Postretirement Benefits Disclosure [Line Items]
Retiree medical coverage provided				5 years
Contribution of pension fund in excess of total contribution				5.00%	5.00%	5.00%
Common Stock
Pension and Other Postretirement Benefits Disclosure [Line Items]
Defined benefit plan equity securities included in common stock | shares	2,030,363	2,030,363
Equity securities, amount	$ 43,600,000	$ 39,000,000
Percentage of total plan assets	11.80%	10.20%
Number of shares sold on open market by the plan | shares					1,000,000
Lump Sums Plan No. 1
Pension and Other Postretirement Benefits Disclosure [Line Items]
Distributions from existing plan assets	$ 48,400,000	$ 50,400,000
Plan No. 1
Pension and Other Postretirement Benefits Disclosure [Line Items]
Settlement loss		$ 15,400,000
Plan No. 2
Pension and Other Postretirement Benefits Disclosure [Line Items]
Settlement loss					$ 0
Lump Sums Plan No. 2
Pension and Other Postretirement Benefits Disclosure [Line Items]
Distributions from existing plan assets	$ 2,000,000				2,000,000
Pension plans
Pension and Other Postretirement Benefits Disclosure [Line Items]
Distributions from existing plan assets				$ 25,014,000	27,046,000	$ 25,494,000
Settlement loss					15,387,000
Actual return on plan assets				6,881,000	$ 11,613,000	$ 73,200,000
Amortization from accumulated other comprehensive income into net periodic cost (benefit)				$ 6,200,000
Expected long-term rate of return on plan assets				8.00%	8.00%	8.00%
Contribution of company to company pension plans				$ 10,436,000	$ 13,435,000	$ 15,254,000
Pension plans | Required
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contribution of company to company pension plans				436,000	5,070,000	5,416,000
Pension plans | Discretionary
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contribution of company to company pension plans				$ 10,000,000	8,365,000	9,838,000
Last Fifteen Years
Pension and Other Postretirement Benefits Disclosure [Line Items]
Average annual return on the plan assets				6.90%
Inception in 1987
Pension and Other Postretirement Benefits Disclosure [Line Items]
Average annual return on the plan assets				9.10%
Non Qualified Pension Plans
Pension and Other Postretirement Benefits Disclosure [Line Items]
Expected company contribution				$ 400,000
Non Qualified Pension Plans | Required
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contribution of company to company pension plans				400,000
Qualified Pension Plans
Pension and Other Postretirement Benefits Disclosure [Line Items]
Expected company contribution				0
Qualified Pension Plans | Discretionary
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contribution of company to company pension plans				10,000,000
Postretirement Benefit Plans
Pension and Other Postretirement Benefits Disclosure [Line Items]
Distributions from existing plan assets				898,000	670,000
Amortization from accumulated other comprehensive income into net periodic cost (benefit)				(700,000)
Contribution of company to company pension plans				674,000	478,000
Contributions by participants				224,000	192,000
Multiemployer Plans
Pension and Other Postretirement Benefits Disclosure [Line Items]
Expense under plans				$ 2,100,000	$ 2,100,000	$ 1,900,000
Red Zone
Pension and Other Postretirement Benefits Disclosure [Line Items]
Percentage of funded under multi employer plans				Less than 65 percent
Yellow Zone
Pension and Other Postretirement Benefits Disclosure [Line Items]
Percentage of funded under multi employer plans				Between 65 and less than 80 percent
Green Zone
Pension and Other Postretirement Benefits Disclosure [Line Items]
Percentage of funded under multi employer plans				At least 80 percent