Stockholders' Equity (Share Repurchases) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2016	Jan. 31, 2015	Jul. 31, 2016	Dec. 15, 2011
Equity [Abstract]
Share Repurchase Program, maximum amount authorized				$ 500.0
Number of common stock repurchased, shares	0	100	0
Cost of common stock repurchased		$ 16.0
Average purchase price per share		$ 159.96
Share Repurchase Program, remaining authorized amount	$ 118.4		$ 118.4