Investments - Schedule of Total Gains and Losses on Equity Securities (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Schedule of Investments [Abstract]
Total (losses) gains recognized on equity securities	$ (9)	$ 33	$ 19	$ 42
Less: Net gains recognized on equity securities sold	0	0	0	0
Unrealized (losses) gains recognized on equity securities held at end of period	$ (9)	$ 33	$ 19	$ 42