Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Feb. 26, 2017	Feb. 28, 2016
Pension Benefits [Member]
Net periodic benefit cost (income):
Service cost	$ 2,463	$ 2,058
Interest cost	9,180	9,472
Expected return on plan assets	(12,115)	(12,134)
Amortization of prior service benefit	(15)	(15)
Amortization of actuarial loss	3,379	3,007
Net periodic benefit cost	2,892	2,388
Changes in accumulated other comprehensive loss:
Actuarial gain (loss)	(9)	152
Amortization of prior service benefit	15	15
Amortization of actuarial loss	(3,379)	(3,007)
Total recognized in accumulated other comprehensive loss	(3,373)	(2,840)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	(481)	(452)
Postretirement Benefits [Member]
Net periodic benefit cost (income):
Service cost	43	50
Interest cost	787	806
Expected return on plan assets	0	0
Amortization of prior service benefit	0	0
Amortization of actuarial loss	318	742
Net periodic benefit cost	1,148	1,598
Changes in accumulated other comprehensive loss:
Actuarial gain (loss)	0	0
Amortization of prior service benefit	0	0
Amortization of actuarial loss	(318)	(742)
Total recognized in accumulated other comprehensive loss	(318)	(742)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	$ 830	$ 856