Employee Retirement and Profit Sharing Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortizations:
Net periodic benefit cost	$ 9,232	$ 5,547	$ 6,717
Pension Plan
Components of net periodic benefit cost:
Service cost	2,688	2,928	3,007
Interest cost	12,335	11,311	11,709
Expected return on plan assets	(15,984)	(17,644)	(19,030)
Amortizations:
Prior service cost	431	431	706
Unrecognized net (gain) loss	9,762	8,521	10,325
Effect of settlement	0	0	0
Net periodic benefit cost	$ 9,232	$ 5,547	$ 6,717