Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 979	$ 2,535	$ 2,017
Other comprehensive income, net of tax
Net unrealized (losses) gains on available-for-sale marketable securities [net of tax benefit (provision) of $10, $8 and ($2), respectively]	(37)	(28)	9
Reclassification adjustment for net losses (gains) on available-for-sale marketable securities included in investment and other income, net [net of tax provision of $0, $0 and $5, respectively]	1	(1)	(16)
Other comprehensive loss	(36)	(29)	(7)
Comprehensive income	$ 943	$ 2,506	$ 2,010