Common Stock Repurchases (Details) - USD ($) shares in Millions	3 Months Ended		6 Months Ended
	May 31, 2016	May 31, 2015	May 31, 2016	May 31, 2015	Mar. 31, 2016
Common Stock Repurchases [Abstract]
Common stock repurchased and retired (in shares)	1.9	1.0	2.4	1.3
Common stock repurchased and retired	$ 48,300,000	$ 25,000,000	$ 60,000,000	$ 32,900,000
Remaining authorized repurchase amount	$ 154,500,000		$ 154,500,000		$ 202,800,000
March 2016 Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized amount for share repurchase programs					$ 100,000,000.0