Net Recognized Gains (Losses) on Equity Investments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net realized gains (losses) on investments sold	$ 43	$ (5)	$ 76	$ 70
Net unrealized gains (losses) on investments still held	299	(22)	725	33
Total	353	(101)	837	4
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	0	(69)	(11)	(100)
Total	$ 342	$ (96)	$ 790	$ 3