Net Sales by Geography (Details) - USD ($) $ in Millions		3 Months Ended
		Jul. 31, 2019	Jul. 31, 2018
Disaggregation of Revenue [Line Items]
Net sales		$ 766	$ 766
United States [Member]
Disaggregation of Revenue [Line Items]
Net sales		374	354
Developed International [Member]
Disaggregation of Revenue [Line Items]
Net sales	[1]	205	215
Emerging [Member]
Disaggregation of Revenue [Line Items]
Net sales	[2]	133	131
Travel Retail [Member]
Disaggregation of Revenue [Line Items]
Net sales	[3]	32	38
Non-branded and bulk [Member]
Disaggregation of Revenue [Line Items]
Net sales	[4]	$ 22	$ 28

[1] Represents net sales of branded products to “advanced economies” as defined by the International Monetary Fund (IMF), excluding the United States. Our largest developed international markets are the United Kingdom, Australia, Germany, France, and Japan.

[2] Represents net sales of branded products to “emerging and developing economies” as defined by the IMF. Our largest emerging markets are Mexico, Poland, Russia, and Brazil.

[3] Represents net sales of branded products to global duty-free customers, other travel retail customers, and the U.S. military regardless of customer location.

[4] Includes net sales of used barrels, bulk whiskey and wine, and contract bottling regardless of customer location.