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Income Taxes - Narrative (Details) - USD ($) $ in Millions |  | 12 Months Ended |
--- | --- | --- | ---
Mar. 01, 2017 | Mar. 31, 2017 | Mar. 31, 2016 | Mar. 31, 2015 | Mar. 31, 2014
Income Tax Contingency [Line Items] |  |  |  |  |
Income tax expense |  | $ 1,614 | $ 908 | $ 815 |
Net discrete tax expense (benefit) |  | 82 | 42 | (33) |
Tax benefit related to adoption of amended accounting guidance |  | 54 | 0 | 0 |
Non-deductible goodwill impairment |  | $ 106 | 0 | $ 0 |
Discrete tax benefit |  |  | $ 25 |  |
Income tax rates |  | 23.40% | 27.90% | 30.70% |
Goodwill impairment charge |  | $ 290 | $ 0 | $ 0 |
Net tax benefit on intellectual property transfer |  | 137 | 0 | 0 |
Tax expense recognized on gain from asset exchange | $ 929 |  |  |  |
Valuation allowance |  | 503 | 267 |  |
Increase in valuation allowance |  | 236 |  |  |
Unrecognized tax benefits |  | 486 | 555 | 616 | $ 647
Unrecognized tax benefits that would Impact income tax expense and the effective tax rate |  | 342 |  |  |
Income tax expense (benefit), before any tax effect, related to accrued interest and penalties |  | (6) | 12 | (24) |
Accrued interest and penalties on unrecognized tax benefits |  | 45 | 77 |  |
Undistributed earnings of foreign operations |  | 6,877 |  |  |
Foreign Tax Authority |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Federal, state and foreign net operating loss carryforwards |  | 1,367 |  |  |
Capital loss carryforwards |  | 624 |  |  |
IRS |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Net discrete tax expense (benefit) |  |  | $ 19 |  |
Canada Revenue Agency |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Net discrete tax expense (benefit) |  |  |  | $ 55 |
Federal |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Federal, state and foreign net operating loss carryforwards |  | 126 |  |  |
State |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Federal, state and foreign net operating loss carryforwards |  | 2,099 |  |  |
Technology Solutions |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Goodwill impairment charge |  | 290 |  |  |
New Accounting Pronouncement, Early Adoption, Effect [Member] |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Tax benefit related to adoption of amended accounting guidance |  | $ 54 |  |  |

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