Employee Benefit Plans - defined benefit plans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Nov. 30, 2014		Nov. 24, 2013		Nov. 25, 2012
Net periodic benefit cost (income):
Curtailment loss (gain)	$ 0		$ (564)		$ (2,391)
Changes in accumulated other comprehensive loss:
Total recognized in accumulated other comprehensive loss	34,682		(104,189)		75,277
Pension plans, defined benefit [Member]
Net periodic benefit cost (income):
Service cost	8,397		8,707		8,952
Interest cost	54,958		51,984		57,635
Expected return on plan assets	(55,521)		(56,183)		(52,029)
Amortization of prior service (benefit) cost	(53)	[1]	(80)	[1]	(78)	[1]
Amortization of actuarial loss	10,932		16,311		12,612
Curtailment loss (gain)	2,614		(564)		(2,391)
Special termination benefit	(35)		(98)		(159)
Net settlement loss	30,558		517		383
Net periodic benefit cost (income)	51,920		20,790		25,243
Changes in accumulated other comprehensive loss:
Actuarial loss (gain)	(92,544)		134,378
Amortization of prior service benefit (cost)	53	[1]	80	[1]
Amortization of actuarial loss	(10,932)		(16,311)
Curtailment gain	113		498
Net settlement loss	(30,712)		(178)
Total recognized in accumulated other comprehensive loss	51,066		(150,289)
Total recognized in net periodic benefit cost (income) and accumulated other comprehensive loss	102,986		(129,499)
Other postretirement benefit plans, defined benefit [Member]
Net periodic benefit cost (income):
Service cost	255		376		397
Interest cost	5,199		4,957		6,634
Expected return on plan assets	0		0		0
Amortization of prior service (benefit) cost	(5)	[1]	(488)	[1]	(16,356)	[1]
Amortization of actuarial loss	4,201		6,765		5,157
Curtailment loss (gain)	733		0		0
Special termination benefit	0		0		0
Net settlement loss	0		0		0
Net periodic benefit cost (income)	10,383		11,610		(4,168)
Changes in accumulated other comprehensive loss:
Actuarial loss (gain)	(6,453)		10,626
Amortization of prior service benefit (cost)	5	[1]	488	[1]
Amortization of actuarial loss	(4,201)		(6,765)
Curtailment gain	0		0
Net settlement loss	0		0
Total recognized in accumulated other comprehensive loss	2,257		(16,903)
Total recognized in net periodic benefit cost (income) and accumulated other comprehensive loss	$ 12,640		$ (5,293)

[1] Postretirement benefits amortization of prior service benefit recognized during 2012 relates primarily to the favorable impact of the February 2004 and August 2003 plan amendments, which concluded amortization in 2012.