Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May. 31, 2015	May. 25, 2014	May. 31, 2015	May. 25, 2014
Changes in accumulated other comprehensive loss:
Total recognized in accumulated other comprehensive loss	$ (2,730)	$ (2,216)	$ (6,829)	$ (4,518)
Pension Benefits [Member]
Net periodic benefit cost (income):
Service cost	2,090	2,166	4,218	4,325
Interest cost	11,790	13,776	23,630	27,537
Expected return on plan assets	(12,716)	(14,036)	(25,433)	(27,879)
Amortization of prior service benefit	(15)	(19)	(31)	(36)
Amortization of actuarial loss	3,163	2,709	6,323	5,405
Curtailment loss	52	4,211	387	4,443
Net settlement gain	0	(133)	0	(73)
Net periodic benefit cost	4,364	8,674	9,094	13,722
Changes in accumulated other comprehensive loss:
Amortization of prior service benefit	15	19	31	36
Amortization of actuarial loss	(3,163)	(2,709)	(6,323)	(5,405)
Curtailment (loss) gain	(52)	115	(387)	115
Net settlement gain	0	29	0	4
Total recognized in accumulated other comprehensive loss	(3,200)	(2,546)	(6,679)	(5,250)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	1,164	6,128	2,415	8,472
Postretirement Benefits [Member]
Net periodic benefit cost (income):
Service cost	62	61	125	129
Interest cost	1,147	1,277	2,294	2,615
Expected return on plan assets	0	0	0	0
Amortization of prior service benefit	0	(2)	0	(3)
Amortization of actuarial loss	1,128	1,087	2,256	2,076
Curtailment loss	0	33	0	733
Net settlement gain	0	0	0	0
Net periodic benefit cost	2,337	2,456	4,675	5,550
Changes in accumulated other comprehensive loss:
Amortization of prior service benefit	0	2	0	3
Amortization of actuarial loss	(1,128)	(1,087)	(2,256)	(2,076)
Curtailment (loss) gain	0	0	0	0
Net settlement gain	0	0	0	0
Total recognized in accumulated other comprehensive loss	(1,128)	(1,085)	(2,256)	(2,073)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	$ 1,209	$ 1,371	$ 2,419	$ 3,477