Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Feb. 24, 2013	Feb. 26, 2012
Net periodic benefit cost (income):
Curtailment (gain) loss	$ 0	$ (773)
Changes in accumulated other comprehensive loss:
Total recognized in accumulated other comprehensive loss	(3,909)	(296)
Pension Benefits [Member]
Net periodic benefit cost (income):
Service cost	2,281	2,247
Interest cost	13,066	14,413
Expected return on plan assets	(14,014)	(13,009)
Amortization of prior service (benefit) cost	(20)	(20)
Amortization of actuarial loss	4,218	3,142
Curtailment (gain) loss	0	(773)
Net settlement loss	45	107
Net periodic benefit cost (income)	5,576	6,107
Changes in accumulated other comprehensive loss:
Actuarial (gain) loss	0	(4)
Amortization of prior service benefit (cost)	20	20
Amortization of actuarial loss	(4,218)	(3,142)
Curtailment gain (loss)	(440)	(1)
Net settlement gain (loss)	0	(51)
Total recognized in accumulated other comprehensive loss	(4,638)	(3,178)
Total recognized in net periodic benefit cost (income) and accumulated other comprehensive loss	938	2,929
Postretirement Benefits [Member]
Net periodic benefit cost (income):
Service cost	94	99
Interest cost	1,239	1,659
Expected return on plan assets	0	0
Amortization of prior service (benefit) cost	(122)	(4,089)
Amortization of actuarial loss	1,691	1,289
Curtailment (gain) loss	0	0
Net settlement loss	0	0
Net periodic benefit cost (income)	2,902	(1,042)
Changes in accumulated other comprehensive loss:
Actuarial (gain) loss	0	0
Amortization of prior service benefit (cost)	122	4,089
Amortization of actuarial loss	(1,691)	(1,289)
Curtailment gain (loss)	0	0
Net settlement gain (loss)	0	0
Total recognized in accumulated other comprehensive loss	(1,569)	2,800
Total recognized in net periodic benefit cost (income) and accumulated other comprehensive loss	$ 1,333	$ 1,758