Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2019	Aug. 31, 2018	Nov. 30, 2018
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income tax expense	$ 23,800,000	$ 27,200,000	$ 37,600,000	$ 165,500,000
Effective tax rate	25.90%	23.70%	20.50%	69.20%
Net (increase) reduction in valuation allowance		$ 3,300,000	$ 3,300,000
Excess tax benefits related to stock-based compensation		(600,000)	(2,900,000)	$ (3,000,000.0)
Tax cuts and jobs act, non-cash charge				111,200,000
Tax cuts and jobs act, re-measurement of deferred tax assets				107,900,000
Tax credits		$ (3,000,000.0)	(4,300,000)	$ 7,200,000
Deferred tax assets	$ 422,300,000		422,300,000		$ 465,400,000
Valuation allowance	20,200,000		20,200,000		23,600,000
Adjustments to deferred tax valuation allowance			0
Gross unrecognized tax benefits (including interest and penalties)	$ 0		$ 0		$ 0