Retirement Plans - Assumptions to Determine Benefit Obligations at Period-end and Net Pension Costs (Detail)	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation, discount rate	3.70%	4.25%	4.64%
Benefit obligation, annual compensation increase	3.60%	3.60%	3.60%
Net cost, discount rate	4.25%	4.64%	4.25%
Net cost, expected return on plan assets	6.00%	6.50%	7.00%
Net cost, annual compensation increase	3.60%	3.60%	3.60%
Other Postretirement Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation, discount rate	3.70%	4.25%	4.40%
Net cost, discount rate	4.25%	4.40%	4.05%