Goodwill (Details) $ in Millions	3 Months Ended
Jun. 30, 2019 USD ($)
Changes in the carrying amount of goodwill by segment [Roll Forward]
Balance as of March 31, 2019, net	$ 7,606
Acquisitions	1,215
Foreign currency translation	(15)
Balance as of June 30, 2019, net	8,806
GBS
Changes in the carrying amount of goodwill by segment [Roll Forward]
Balance as of March 31, 2019, net	4,599
Acquisitions	1,215
Foreign currency translation	(9)
Balance as of June 30, 2019, net	5,805
GIS
Changes in the carrying amount of goodwill by segment [Roll Forward]
Balance as of March 31, 2019, net	3,007
Acquisitions	0
Foreign currency translation	(6)
Balance as of June 30, 2019, net	$ 3,001

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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