Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended				12 Months Ended
	Nov. 30, 2019	Feb. 28, 2019	Nov. 30, 2018	Feb. 28, 2018	Nov. 30, 2022	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2018	Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2016
Income Tax Contingency [Line Items]
Impact of Tax Reform	$ (1,300,000)		$ (1,300,000)			$ 0	$ (112,458,000)			$ 0
Impact of Tax Return, re-measurement of deferred tax assets						1,900,000	106,700,000
Provisional impact of Tax Reform		$ 111,200,000		$ 111,200,000
Income Tax Credits and Adjustments						(4,300,000)	10,700,000			4,900,000
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount						$ (4,400,000)	(2,000,000)			$ (1,200,000)
Effective Income Tax Rate Reconciliation, Percent						(22.80%)		(53.70%)		(37.70%)
Income Taxes (Textual) [Abstract]
Income tax expense						$ (79,400,000)	(197,600,000)			$ (109,400,000)
Deferred Tax Assets, Net	(383,700,000)		(465,400,000)			(383,700,000)	(465,400,000)	$ (465,400,000)	$ (465,400,000)
Net Increase in valuation allowance recorded against net deferred tax assets						$ (4,400,000)	(3,300,000)			1,200,000
Period for Carry forward of tax benefits related to deferred tax assets						20 years
Deferred Tax Assets, Operating Loss Carryforwards, State and Local, Expired							1,200,000
Deferred Tax Assets, Tax Credit Carryforwards	77,400,000					$ 77,400,000
Valuation allowance	(19,200,000)		(23,600,000)			(19,200,000)	(23,600,000)	(23,600,000)	(23,600,000)
Unrecognized tax benefits that if recognized would affect the Company's annual effective tax rate	0		0			0	0	0	0	100,000
Total accrued interest and penalties related to unrecognized income tax benefits	0		0			0	0	0	0
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	0		0			0	0	0	0
Unrecognized Tax Benefits	0		0			0	0	0	0	$ 56,000	$ 56,000
Valuation allowance against net deferred tax assets	19,200,000		23,600,000			19,200,000	23,600,000	23,600,000	23,600,000
Total deferred tax assets	438,733,000		524,951,000			438,733,000	524,951,000	$ 524,951,000	$ 524,951,000
Share-based Payment Arrangement, Expense, Tax Benefit						$ (5,300,000)	(1,000,000.0)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent						21.00%		22.20%	22.00%	35.00%
Effective Income Tax Rate Reconciliation, Deduction, Percent						50.00%
Deferred Tax Assets, Tax Credit Carryforwards	180,737,000		$ 231,100,000			$ 180,737,000	231,100,000	$ 231,100,000	$ 231,100,000
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent						(0.20%)		0.20%		(0.30%)
Tax Cuts and Jobs Act of 2017, Other Tax Effect, Income Tax Expense (Benefit)							2,500,000
Maximum
Income Tax Contingency [Line Items]
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation	1,000,000					$ 1,000,000
Tax Credit Carryforward, Expiring in 2038 [Domain]
Income Tax Contingency [Line Items]
Future Income From Continuing Operations Before Income Taxes						1,300,000,000
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount							(2,100,000)
Income Taxes (Textual) [Abstract]
Net Increase in valuation allowance recorded against net deferred tax assets							$ 3,300,000
Operating Loss Carryforwards	$ 95,500,000					$ 95,500,000
Forecast [Member]
Income Taxes (Textual) [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards					$ 50,000,000.0
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent					6.60%