Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Statement of Comprehensive Income [Abstract]
Net income	$ 812	$ 357
Other comprehensive income, net of tax
Net unrealized gains (losses) on available-for-sale debt securities [net of tax (provision) benefit of ($1) and $1, respectively]	2	(5)
Reclassification of net losses realized on available-for-sale debt securities included in investment and other income, net [net of tax provision of $0 and $0, respectively]	1	3
Other comprehensive income (loss)	3	(2)
Comprehensive income	$ 815	$ 355