Segment Information (Details) $ in Millions	6 Months Ended	12 Months Ended
	Apr. 30, 2017 USD ($) business_acquired segment	Oct. 31, 2016 USD ($)
Segment Reporting [Abstract]
Number of segments | segment	4
Advance royalty proceeds received from intercompany advanced royalty payments and licensing arrangements | $	$ 439	$ 3,700
Royalty recognition term	5 years
Number of businesses acquired | business_acquired	5