Employee Benefit Plans - defined benefit plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 29, 2015	Nov. 30, 2014	Nov. 24, 2013
Net periodic benefit cost:
Curtailment loss (gain)	$ 0	$ 0	$ (564)
Changes in accumulated other comprehensive loss:
Total recognized in accumulated other comprehensive loss	(25,114)	34,682	(104,189)
Pension plans, defined benefit [Member]
Net periodic benefit cost:
Service cost	8,352	8,397	8,707
Interest cost	47,179	54,958	51,984
Expected return on plan assets	(50,825)	(55,521)	(56,183)
Amortization of prior service (benefit) cost	(61)	(53)	(80)
Amortization of actuarial loss	12,578	10,932	16,311
Curtailment loss (gain)	656	2,614	(564)
Special termination benefit	0	35	98
Net settlement (gain) loss	(45)	30,558	517
Net periodic benefit cost	17,834	51,920	20,790
Changes in accumulated other comprehensive loss:
Actuarial (gain) loss	15,228	(92,544)
Amortization of prior service benefit (cost)	61	53
Amortization of actuarial loss	(12,578)	(10,932)
Curtailment (loss) gain	(656)	113
Net settlement gain (loss)	45	(30,712)
Total recognized in accumulated other comprehensive loss	(28,356)	51,066
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	(10,522)	102,986
Other postretirement benefit plans, defined benefit [Member]
Net periodic benefit cost:
Service cost	251	255	376
Interest cost	4,588	5,199	4,957
Expected return on plan assets	0	0	0
Amortization of prior service (benefit) cost	0	(5)	(488)
Amortization of actuarial loss	4,511	4,201	6,765
Curtailment loss (gain)	0	733	0
Special termination benefit	0	0	0
Net settlement (gain) loss	0	0	0
Net periodic benefit cost	9,350	10,383	$ 11,610
Changes in accumulated other comprehensive loss:
Actuarial (gain) loss	5,918	(6,453)
Amortization of prior service benefit (cost)	0	5
Amortization of actuarial loss	(4,511)	(4,201)
Curtailment (loss) gain	0	0
Net settlement gain (loss)	0	0
Total recognized in accumulated other comprehensive loss	(10,429)	2,257
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	$ (1,079)	$ 12,640