Net Sales by Geography (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020		Oct. 31, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 985	$ 989	$ 1,738		$ 1,755
United States [Member]
Disaggregation of Revenue [Line Items]
Net sales	522	506	909		880
Developed International [Member]
Disaggregation of Revenue [Line Items]
Net sales	266	248	497	[1]	453	[1]
Emerging [Member]
Disaggregation of Revenue [Line Items]
Net sales	160	173	267	[2]	306	[2]
Travel Retail [Member]
Disaggregation of Revenue [Line Items]
Net sales	22	38	35	[3]	70	[3]
Non-branded and bulk [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 15	$ 24	$ 30	[4]	$ 46	[4]

[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, Germany, Australia, and France.

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

[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.