Employee Retirement and Profit Sharing Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amortizations:
Net periodic benefit cost	$ 5,547	$ 6,717	$ 6,805
Pension Plan
Components of net periodic benefit cost:
Service cost	2,928	3,007	3,173
Interest cost	11,311	11,709	12,171
Expected return on plan assets	(17,644)	(19,030)	(18,531)
Amortizations:
Prior service cost	431	706	857
Unrecognized net (gain) loss	8,521	10,325	8,822
Effect of settlement	0	0	313
Net periodic benefit cost	$ 5,547	$ 6,717	$ 6,805