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Amount remaining of a stock repurchase plan authorized.

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Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Millions			3 Months Ended			6 Months Ended
	Jul. 29, 2020 $ / shares	Jul. 28, 2020 $ / shares	Sep. 30, 2020 USD ($) vote $ / shares shares	Jun. 30, 2020 shares	Sep. 30, 2019 $ / shares	Sep. 30, 2020 USD ($) vote $ / shares	Sep. 30, 2019 $ / shares
Accelerated Share Repurchases [Line Items]
Number of votes per share of common stock permitted on proposals presented to stockholders (vote) \| vote			1			1
Dividends declared per common share (in dollars per share) \| $ / shares	$ 0.42	$ 0.41	$ 0.42		$ 0.41	$ 0.83	$ 0.80
Average price of shares repurchased (in usd per share) \| $ / shares			$ 151.23
Open Market Share Repurchase Transactions
Accelerated Share Repurchases [Line Items]
Common stock repurchased (in shares) \| shares			1,800,000	0
Shares repurchased			$ 269
Authorized amount available for future repurchases			1,300			$ 1,300
Open Market Share Repurchase Transactions \| Other accrued liabilities
Accelerated Share Repurchases [Line Items]
Shares repurchased			$ 21