Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 119	$ 622	$ 289	$ 1,543
Other comprehensive income, net of tax
Net unrealized (losses) gains on available-for-sale marketable securities [net of tax benefit (provision) of $7, ($1), $14 and $2, respectively]	(25)	(2)	(51)	7
Reclassification adjustment for net losses on available-for-sale marketable securities included in investment and other income, net [net of tax provision of $0, $0, $0 and $0, respectively]	2	0	2	0
Other comprehensive (loss) income	(23)	(2)	(49)	7
Comprehensive income	$ 96	$ 620	$ 240	$ 1,550