Stockholders' Equity (Details) - $ / shares	2 Months Ended	12 Months Ended
	Dec. 21, 2017	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Share Repurchase Program
Number of shares purchased		7,694,000	13,652,000	1,665,000
Average price per share		$ 37.81	$ 28.77	$ 34.17
Remaining authorization at October 31		8,144,000	15,838,000	18,535,000
Subsequent Event [Member]
Share Repurchase Program
Number of shares purchased	4,200,000
Average price per share	$ 47.47