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Restructuring - Schedule of Restructuring and Related Expenses (Details) $ in Millions | 3 Months Ended | 15 Months Ended
--- | --- | ---
Mar. 31, 2018 USD ($) | Mar. 31, 2018 USD ($)
Restructuring Cost and Reserve [Line Items] |  |
Estimated Remaining Costs | $ 454 | $ 454
2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 74 | 571
Expected total cost | 1,025 | 1,025
Workforce reduction | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 33 | 332
Estimated Remaining Costs | 118 | 118
Expected total cost | 450 | 450
Technology rationalization | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 10 | 43
Estimated Remaining Costs | 87 | 87
Expected total cost | 130 | 130
Contract termination costs incurred | 0 | 2
Expected contract termination cost remaining | 15 | 15
Lease consolidation | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 3 | 11
Estimated Remaining Costs | 74 | 74
Expected total cost | 85 | 85
Contract termination costs incurred | 2 | 10
Expected contract termination cost remaining | 80 | 80
Asset impairments | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 1 | 27
Estimated Remaining Costs | 23 | 23
Expected total cost | 50 | 50
Other Restructuring | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 27 | 158
Estimated Remaining Costs | 152 | 152
Expected total cost | 310 | 310
Contract termination costs incurred | 4 | 7
Expected contract termination cost remaining | $ 80 | $ 80

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- Definition Amount expected to be recognized in earnings for the specified restructuring cost. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4(b)) -URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747 + Details
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- Definition Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4(b)) -URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747 + Details
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