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Acquisitions and Divestitures - Merger and Integration Expenses (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Business Acquisition [Line Items] |  |  |  |
Merger and integration expense | $ 32 | $ 14 | $ 102 | $ 20
Personal expense |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Merger and integration expense | 16 | 5 | 37 | 6
Legal and professional fees |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Merger and integration expense | 4 | 5 | 7 | 7
Net occupancy expense |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Merger and integration expense | 0 | (1) | 3 | (1)
Other expense |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Merger and integration expense | $ 12 | $ 5 | $ 55 | $ 8

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- Definition Costs incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs. + References No definition available. + Details
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