Postretirement Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2015
Postretirement Benefits Additional (Textual) [Abstract]
Interest cost	$ 2,274	$ 2,285	$ 2,270
Amortization of prior service cost	1,556	1,556	1,556
Service cost	1,046	1,045	1,142
Amortization of net actuarial loss	142	79	848
Total	5,018	4,965	5,816
Liabilities related to postretirement benefit plan	$ 66,500	$ 62,200
Discounted rate for benefit plan	3.50%	3.60%
Defined Benefit Plan Disclosure [Line Items]
Cash surrender value of insurance contracts	$ 75,236	$ 70,829
2014	2,000
2015	2,500
2016	2,800
2017	3,500
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	3,600
2018 - 2022	20,300
Supplemental Nonqualified Unfunded Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)	3,900	400	(1,300)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	1,500	1,400	1,400
Cash surrender value of insurance contracts	46,800	44,400
Unfunded Death Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)	1,500	200	$ (300)
Cash surrender value of insurance contracts	$ 18,500	$ 17,000