Employee Retirement and Profit Sharing Plans - Narrative (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Unrecognized prior service costs, before tax	$ 2,600	$ 2,100
Unrecognized prior service costs, net of tax	1,600	1,300
Unrecognized actuarial losses, before tax	122,100	141,500
Unrecognized actuarial losses, net of tax	74,400	87,400
Prior service costs expected to be recognized next fiscal year	400
Prior service costs expected to be recognized next fiscal year, net of tax	300
Actuarial losses expected to be recognized next fiscal year	8,500
Actuarial losses expected to be recognized next fiscal year, net of tax	6,300
Noncurrent defined benefit pension plan asset	5,100
Noncurrent defined benefit pension plan liability	9,200
Current accrued pension liability	900
Accumulated benefit obligation for all defined benefit plans	$ 346,000	336,300
Frozen defined benefit plan obligations (as a percent)	90.00%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Plan participants' contributions allowed (as a percent)	1.00%
Plans in green zone (more than) (as a percent)	80.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Plan participants' contributions allowed (as a percent)	50.00%
Plans in red zone (less than) (as a percent)	65.00%
Plans in yellow zone (less than) (as a percent)	80.00%
De-risking strategy in 2014 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Targets investment in equity securities, fixed income, cash equivalents and other investments (as a percent)	30.00%
De-risking strategy in 2014 | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Targets investment in equity securities, fixed income, cash equivalents and other investments (as a percent)	70.00%
De-risking strategy in 2014 | Other Investments
Defined Benefit Plan Disclosure [Line Items]
Targets investment in equity securities, fixed income, cash equivalents and other investments (as a percent)	1.00%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Funded status at end of year	$ (5,024)	$ (56,550)