Net Recognized Gains (Losses) on Equity Investments (Detail) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net realized gains on investments sold	$ 17	$ 22
Net unrealized gains (losses) on investments still held	100	(56)
Total	125	(57)
Equity Securities
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Impairments of investments	(9)	(22)
Total	$ 108	$ (56)