Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Jun. 05, 2020	Feb. 28, 2020	Sep. 30, 2019
Accounts receivable, allowances	$ 21			$ 17
Class A Common Stock
Par value (in dollars per share)	$ 0.001			$ 0.001
Shares authorized (in shares)	1,000,000,000		1,000,000,000	1,000,000,000
Shares issued (in shares)	77,000,000			0
Shares outstanding (in shares)	77,000,000	77,000,000		0
Class B Common Stock
Par value (in dollars per share)	$ 0.001			$ 0.001
Shares authorized (in shares)	1,000,000,000		1,000,000,000	1,000,000,000
Shares issued (in shares)	433,000,000			505,830,022
Shares outstanding (in shares)	433,000,000	433,000,000	510,000,000	505,830,022