Common Stock, Voting Rights, Number of Votes Per Common Share

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Aggregate dividends declared during the period for each share of common stock outstanding.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of stock repurchase plan authorized.

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Amount remaining of a stock repurchase plan authorized.

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Amount, before tax, of increase (decrease) in the cumulative translation adjustment from gain (loss) on foreign currency derivatives that are designated as, and are effective as, economic hedges of a net investment in a foreign entity.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Amount of decrease of par value, additional paid in capital (APIC) and retained earnings of common and preferred stock retired from treasury when treasury stock is accounted for under the par value method.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Number of shares of common and preferred stock retired from treasury during the period.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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Stockholders' Equity - Narrative (Details) $ / shares in Units, shares in Millions	1 Months Ended								2 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2018 shares	Mar. 31, 2018 USD ($) vote	Aug. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Apr. 30, 2017 shares	Mar. 31, 2017 USD ($) shares	Feb. 29, 2016 USD ($)	Jul. 31, 2015 $ / shares	Apr. 30, 2017 $ / shares shares	Mar. 31, 2016 USD ($) $ / shares shares	Mar. 31, 2018 USD ($) vote $ / shares shares	Mar. 31, 2017 USD ($) $ / shares shares	Mar. 31, 2016 USD ($) $ / shares shares	May 24, 2018 USD ($)	Oct. 31, 2016 USD ($)	Oct. 31, 2015 USD ($)	May 31, 2015 USD ($)	Mar. 31, 2015 USD ($)
Dividends Payable [Line Items]
Number of votes \| vote		1									1
Cash dividends declared per common share (in dollars per share) \| $ / shares											$ 1.30	$ 1.12	$ 1.08
Shares repurchase plans authorized															$ 4,000,000,000.0	$ 2,000,000,000	$ 500,000,000
Shares bought (in shares) \| shares											10.5	15.5	8.7
Shares repurchased											$ 1,650,000,000	$ 2,250,000,000	$ 1,504,000,000
Average price paid per share (in dollars per share) \| $ / shares											$ 151.06	$ 141.16	$ 173.64
Total authorization outstanding for repurchases of common stock		$ 1,096,000,000				$ 2,746,000,000				$ 996,000,000	$ 1,096,000,000	$ 2,746,000,000	$ 996,000,000					$ 0
Repurchase of common stock											1,650,000,000	2,250,000,000	$ 1,504,000,000
Treasury stock retired (in shares) \| shares													115.5
Other comprehensive income (loss) before reclassifications											604,000,000	(688,000,000)
Net foreign currency translation gains (losses)											609,000,000	(659,000,000)	$ 172,000,000
Losses from net investment hedges											$ 268,000,000	$ 13,000,000
Treasury Stock
Dividends Payable [Line Items]
Repurchase of common stock (in shares) \| shares											11.0	16.0	9.0
Repurchase of common stock											$ 1,614,000,000	$ 2,200,000,000	$ 1,504,000,000
Retirement of common stock													7,800,000,000
Retained Earnings
Dividends Payable [Line Items]
Retirement of common stock													6,400,000,000
Additional Paid-in Capital
Dividends Payable [Line Items]
Repurchase of common stock (in shares) \| shares											36.0
Repurchase of common stock												50,000,000
Retirement of common stock													1,500,000,000
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest
Dividends Payable [Line Items]
Other comprehensive income (loss) before reclassifications											$ 804,000,000	(644,000,000)	113,000,000
Net foreign currency translation gains (losses)											804,000,000	(624,000,000)	$ 113,000,000
Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest
Dividends Payable [Line Items]
Net foreign currency translation gains (losses)											189,000,000	(74,000,000)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Including Portion Attributable to Noncontrolling Interest
Dividends Payable [Line Items]
Other comprehensive income (loss) before reclassifications											$ (4,000,000)	$ (5,000,000)
Open Market Transactions
Dividends Payable [Line Items]
Shares bought (in shares) \| shares													4.5
Shares repurchased													$ 854,000,000
Average price paid per share (in dollars per share) \| $ / shares											$ 144.43	$ 140.96	$ 192.27
Repurchase of common stock (in shares) \| shares											3.5	14.1
Repurchase of common stock											$ 500,000,000	$ 2,000,000,000
Accelerated Share Repurchase
Dividends Payable [Line Items]
Shares bought (in shares) \| shares					0.3	1.4			1.7	4.2
Shares repurchased		$ 500,000,000	$ 400,000,000	$ 250,000,000		$ 250,000,000	$ 650,000,000
Average price paid per share (in dollars per share) \| $ / shares									$ 143.19	$ 154.04
June 2017 Accelerated Share Repurchase
Dividends Payable [Line Items]
Shares bought (in shares) \| shares											1.5
August 2017 Accelerated Share Repurchase
Dividends Payable [Line Items]
Shares bought (in shares) \| shares											2.7
March 2018 ASR Program
Dividends Payable [Line Items]
Shares bought (in shares) \| shares											2.5
Minimum
Dividends Payable [Line Items]
Cash dividends declared per common share (in dollars per share) \| $ / shares								$ 0.28
Maximum
Dividends Payable [Line Items]
Cash dividends declared per common share (in dollars per share) \| $ / shares								$ 0.34
Subsequent Event
Dividends Payable [Line Items]
Shares repurchase plans authorized														$ 4,000,000,000
Total authorization outstanding for repurchases of common stock														$ 5,100,000,000
Subsequent Event \| March 2018 ASR Program
Dividends Payable [Line Items]
Shares bought (in shares) \| shares	0.5