Stockholders' Equity - Schedule of Share Repurchases (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020	Feb. 28, 2022
Accelerated Share Repurchases [Line Items]
Shares repurchase authorization increase in 2021	$ 4,000	$ 2,000
Approximate Dollar Value of Shares that May Yet Be Purchased Under the Programs
Beginning balance	2,785	1,535	$ 3,469
Ending balance	$ 3,278	2,785	$ 1,535
Other accrued liabilities
Approximate Dollar Value of Shares that May Yet Be Purchased Under the Programs
Accrued shares repurchased		$ 8
Open Market Transactions
Accelerated Share Repurchases [Line Items]
Total Number of Shares Purchased (in shares)	4.6	4.7	9.2
Average price paid per share (in dollars per share)	$ 217.73	$ 160.33	$ 144.68
Approximate Dollar Value of Shares that May Yet Be Purchased Under the Programs
Shares repurchased	$ (1,007)	$ (750)	$ (1,334)
Accelerated Share Repurchase, May 2019
Accelerated Share Repurchases [Line Items]
Total Number of Shares Purchased (in shares)			4.7
Average price paid per share (in dollars per share)			$ 127.68
Approximate Dollar Value of Shares that May Yet Be Purchased Under the Programs
Shares repurchased			$ (600)
Accelerated Share Repurchase, May 2021
Accelerated Share Repurchases [Line Items]
Total Number of Shares Purchased (in shares)	5.2
Average price paid per share (in dollars per share)	$ 193.22
Approximate Dollar Value of Shares that May Yet Be Purchased Under the Programs
Shares repurchased	$ (1,000)
Accelerated Share Repurchase, February 2022
Accelerated Share Repurchases [Line Items]
Total Number of Shares Purchased (in shares)	4.8
Average price paid per share (in dollars per share)	$ 265.56
Shares repurchase authorization increase in 2021				$ 1,500
Approximate Dollar Value of Shares that May Yet Be Purchased Under the Programs
Shares repurchased	$ (1,500)