Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 2,535	$ 2,017	$ 913
Other comprehensive income, net of tax
Net unrealized (losses) gains on available-for-sale marketable securities [net of tax benefit (provision) of $8, ($2) and ($4), respectively]	(28)	9	13
Reclassification adjustment for net gains on available-for-sale marketable securities included in investment and other income, net [net of tax provision of $0, $5 and $0, respectively]	(1)	(16)	(1)
Other comprehensive (loss) income	(29)	(7)	12
Comprehensive income	$ 2,506	$ 2,010	$ 925