Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Feb. 23, 2020	Feb. 24, 2019
Net periodic benefit cost:
Net periodic benefit cost	$ 2,213	$ 4,870
Total pension plan contributions	10,500
Pension Benefits [Member]
Net periodic benefit cost:
Net periodic benefit cost	1,704	3,977
Postretirement Benefits [Member]
Net periodic benefit cost:
Net periodic benefit cost	$ 509	$ 893