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Leases - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Mar. 31, 2020 | Mar. 31, 2019 | Mar. 31, 2018
Lessee, Lease, Description [Line Items] |  |  |
Rent expense |  | $ 576 | $ 568
Minimum sublease income | $ 178 |  |
Future lease payments | 149 |  |
Future minimum lease payments for sale leaseback transaction |  | 49 |
Minimum sublease income, due under future noncancelable subleases |  | $ 133 |
Total lease receivable | $ 272 |  |
Remaining lease term | 7 years |  |
Minimum |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Noncancelable lease terms | 2 years |  |
Maximum |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Noncancelable lease terms | 15 years |  |
Building | Minimum |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lease term | 1 year |  |
Building | Maximum |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lease term | 15 years |  |
Equipment | Minimum |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lease term | 1 year |  |
Equipment | Maximum |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lease term | 5 years |  |
Real Property |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Renewal option increments for leases (in years) | 5 years |  |

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- Definition Lessee, Operating Lease, Lease Not yet Commenced, Future Lease Payments + References No definition available. + Details
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- Definition Lessor, Lease, Payments to be Received + References No definition available. + Details
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- Definition Lessor, Sales-type and Direct Financing Leases, Weighted Average Remaining Lease Term + References No definition available. + Details
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- Definition 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. + References No definition available. + Details
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- Definition Term of lessee's operating lease not yet commenced, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
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- Definition Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
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- Definition Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
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- Definition Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 40 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77914019&loc=d3e50824-112756 + Details
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- Definition Contractually required future rental payments receivable on noncancelable subleasing arrangements. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717 + Details
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- Definition Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41499-112717 + Details
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- Definition Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 30 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=119202524&loc=SL77919391-209981 + Details
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