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Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income tax expense related to continuing operations	$ 95	$ 239
Net discrete tax expense (benefit)	$ 3	(35)
Tax benefit recognized related to excess tax benefits arising from adoption of ASU 2016-09		$ 37
Income tax rate (as a percent)	20.70%	26.20%
Unrecognized tax benefits	$ 516
Unrecognized tax benefits that would reduce income tax expense and the effective tax rate	371
Decrease in unrecognized tax benefits that could result from audit resolutions	$ 60

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Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount

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Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
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-Section 50
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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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