Income Taxes (Details) - USD ($)	3 Months Ended				9 Months Ended
	Aug. 31, 2020	May 31, 2020	Feb. 29, 2020	Aug. 31, 2019	Aug. 31, 2020	Aug. 31, 2019	Nov. 30, 2019
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income tax expense	$ 22,900,000			$ 23,800,000	$ 47,800,000	$ 37,600,000
Effective tax rate	22.60%			25.90%	20.10%	20.50%
Net (increase) reduction in valuation allowance	$ 100,000					$ (3,300,000)
Excess tax benefits related to stock-based compensation					$ (5,600,000)	(2,900,000)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount	1,200,000			$ 1,400,000	3,200,000	2,600,000
Income Taxes Receivable, Alternative Minimum Tax, CARES Act		$ 39,300,000	$ 43,300,000
Tax credits	(3,100,000)				(10,100,000)	(4,300,000)
Deferred tax assets	260,500,000				260,500,000		$ 383,700,000
Valuation allowance	19,300,000				19,300,000		19,200,000
Deferred Tax Assets, Tax Credit Carryforwards	82,617,000			$ 0	82,617,000	$ 0
Adjustments to deferred tax valuation allowance					0
Gross unrecognized tax benefits (including interest and penalties)	0				0		$ 0
Income Taxes Receivable, Current	$ 43,300,000				$ 43,300,000