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Restructuring - Narrative (Details) - 2017 Plan $ in Millions | 3 Months Ended | 6 Months Ended | 30 Months Ended
--- | --- | --- | ---
Jun. 30, 2019 USD ($) | Jun. 30, 2019 USD ($) job_elimination | Jun. 30, 2019 USD ($) job_elimination
Restructuring Cost and Reserve [Line Items] |  |  |
Restructuring charges | $ 125 | $ 204 |
Expected total cost | 1,350 | 1,350 | $ 1,350
Number of positions eliminated to date | job_elimination |  |  | 5,091
Costs incurred | 127 | 218 | $ 1,200
Workforce reduction |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |
Expected total cost | 530 | 530 | 530
Costs incurred | 78 | 102 | 516
Technology rationalization |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |
Expected total cost | 130 | 130 | 130
Costs incurred | 4 | 15 | 95
Lease consolidation |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |
Expected total cost | 80 | 80 | 80
Costs incurred | 5 | 14 | 50
Asset impairments |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |
Expected total cost | 45 | 45 | 45
Costs incurred | 2 | 2 | 41
Other Restructuring |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |
Expected total cost | 565 | 565 | 565
Costs incurred | $ 38 | $ 85 | $ 498
Minimum |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |
Expected number of positions eliminated | job_elimination |  | 5,000 |
Maximum |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |
Expected number of positions eliminated | job_elimination |  | 5,600 |

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