Acquisitions - Summary of HPES Purchase Price (Details) - USD ($) $ in Millions	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 3,179	$ 2,022	$ 0
Hewlett Packard Enterprise Services
Business Acquisition [Line Items]
Cash and cash equivalents		0
Accounts receivable		403
Prepaid expenses		86
Other current assets		22
Total current assets		511
Property and equipment		183
Intangible assets		976
Other assets		28
Total assets acquired		1,698
Current capital lease obligations, accounts payable, accrued payroll, accrued expenses, and other current liabilities		418
Deferred revenue		71
Non-current capital lease liability		162
Non-current deferred tax liabilities		204
Other liabilities		15
Total liabilities assumed		870
Net identifiable assets acquired		828
Goodwill		2,022
Total estimated consideration transferred		$ 2,850