Pension and Other Postretirement Benefits - Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 29, 2015	Aug. 30, 2014	Aug. 29, 2015	Aug. 30, 2014
Amortization of unrecognized:
Cash contributions	$ 116		$ 399
Pension Plan [Member]
Components of net periodic benefit cost (income):
Service cost	361	$ 499	1,430	$ 1,495
Interest cost	2,020	1,934	5,767	5,798
Expected return on plan assets	(2,843)	(2,835)	(8,686)	(8,500)
Curtailment	1	0	1	0
Amortization of unrecognized:
Prior service cost	(2)	(3)	(4)	(9)
Net actuarial loss (gain)	826	721	2,760	2,163
Net periodic benefit cost	363	316	1,268	947
Cash contributions	101	66	354	193
Postretirement Healthcare Benefit Plan [Member]
Components of net periodic benefit cost (income):
Interest cost	2	2	6	6
Amortization of unrecognized:
Prior service cost	(31)	(31)	(93)	(93)
Net actuarial loss (gain)	(37)	(37)	(111)	(111)
Net periodic benefit cost	(66)	(66)	(198)	(198)
Cash contributions	15	$ 16	$ 45	$ 48
J.L. Clark, Inc [Member] | Pension Plan [Member]
Amortization of unrecognized:
Reduction of projected benefit obliation and pension liability	$ (3,988)