Common Stock Repurchases (Details) - USD ($)	3 Months Ended		9 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2020	Aug. 31, 2019	Jan. 31, 2020	Nov. 30, 2019
Equity [Abstract]
Stock repurchase authorization					$ 250,000,000	$ 75,000,000
Common stock repurchased and retired (in shares)	0	0	400,000	700,000
Common stock repurchased and retired			$ 20,000,000	$ 25,000,000
Remaining authorized repurchase amount	$ 230,000,000		$ 230,000,000