Stockholders' Equity (Share Repurchases) (Details) - USD ($)	3 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Mar. 21, 2017	Dec. 15, 2011
Equity [Abstract]
Share Repurchase Program, maximum amount authorized			$ 1,000,000,000.0	$ 500,000,000.0
Number of common stock repurchased, shares	0	0
Share Repurchase Program, remaining authorized amount	$ 563,500,000