Employee Retirement and Profit Sharing Plans - Assumptions used to Determine Net Periodic Benefit Cost (Details) - Pension Plan	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Effective discount rate for benefit obligations (as a percent)	3.69%	4.29%	4.53%
Effective rate for interest on benefit obligations (as a percent)	3.32%	3.56%	3.76%
Effective discount rate for service cost (as a percent)	3.79%	4.51%	4.67%
Effective rate for interest on service cost (as a percent)	3.51%	3.91%	4.14%
Expected return on assets (as a percent)	5.25%	6.25%	6.75%
Rate of compensation increase (as a percent)	3.70%	3.70%	4.00%