Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 365	$ 1,421
Other comprehensive income (loss), net of tax:
Net gains (losses) on available-for-sale securities	11	3
Net gains (losses) on derivative instruments	(37)	9
Foreign currency translation adjustments	24	1
Total other comprehensive income (loss), net of tax	(2)	13
Total comprehensive income (loss)	$ 363	$ 1,434