Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Net Cash Provided by Operating Activities [Abstract]
Net income	$ 837	$ 3,039	$ 1,019
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities [Abstract]
Depreciation, amortization and accretion	181	150	145
Acquisition-related contingent consideration	0	5	14
Stock-based compensation	435	347	284
Increase (Decrease) in Operating Capital [Abstract]
Receivables, net	(41)	164	(88)
Other assets	(70)	35	(24)
Accounts payable	18	(36)	59
Accrued and other liabilities	136	119	3
Deferred income taxes, net	(143)	(1,871)	(16)
Deferred net revenue (online-enabled games)	581	(155)	151
Net Cash Provided by Operating Activities	1,934	1,797	1,547
Net Cash Provided by (Used in) Investing Activities [Abstract]
Capital expenditures	(124)	(140)	(119)
Proceeds from maturities and sales of short-term investments	3,686	2,142	1,688
Purchase of short-term investments	(2,828)	(3,359)	(1,342)
Acquisition, net of cash acquired	(1,239)	0	(58)
Net Cash Provided by (Used in) Investing Activities	(505)	(1,357)	169
Net Cash Used in Financing Activities [Abstract]
Proceeds from Debt, Net of Issuance Costs	1,478
Repayments of Senior Debt	(600)
Proceeds from issuance of common stock	86	62	61
Payments of Dividends	(98)
Cash paid to taxing authorities for shares withheld from employees	(152)	(91)	(122)
Repurchase and retirement of common stock	(729)	(1,207)	(1,192)
Payment for Contingent Consideration Liability, Financing Activities	0	(122)	0
Net Cash Used in Financing Activities, Total	(15)	(1,358)	(1,253)
Effect of foreign exchange on cash and cash equivalents	78	(22)	(13)
Increase (decrease) in cash and cash equivalents	1,492	(940)	450
Beginning cash and cash equivalents	3,768	4,708	4,258
Ending cash and cash equivalents	5,260	3,768	4,708
Supplemental Cash Flow Information [Abstract]
Cash paid during the year for income taxes, net	340	170	100
Cash paid during the year for interest	40	42	42
Non-cash investing activities:
Capital Expenditures Incurred but Not yet Paid	$ 17	$ (8)	$ 8