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Derivatives and Hedging - Schedule of amounts of derivative gains (losses) recognized in the Consolidated Financial Statements (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017
Derivative [Line Items] |  |  |  |
Gain (Loss) Currently Recognized in Accumulated Other Comprehensive Loss | $ (3) | $ 11 | $ (14) | $ 18
Hedge gain (loss) to be reclassified during next twelve months |  |  | (12) |
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) | (3) | (3) | (9) | 3
Compensation and benefits |  |  |  |
Derivative [Line Items] |  |  |  |
Hedge gain (loss) to be reclassified during next twelve months | (4) | 0 | (8) | 9
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) | 0 | 1 | 1 | 14
Other general expenses |  |  |  |
Derivative [Line Items] |  |  |  |
Hedge gain (loss) to be reclassified during next twelve months | 0 | 3 | 3 | 5
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) | 0 | (1) | (2) | (3)
Interest expense |  |  |  |
Derivative [Line Items] |  |  |  |
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) | 0 | 0 | (1) | (1)
Other income (expense) |  |  |  |
Derivative [Line Items] |  |  |  |
Hedge gain (loss) to be reclassified during next twelve months | 1 | 8 | (9) | 4
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) | $ (3) | $ (3) | $ (7) | $ (7)

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- Definition Represents the estimated net amount of unrealized gains (losses) on hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References No definition available. + Details
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- Definition Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e637-108580 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=109978405&loc=d3e80720-113993 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580 + Details
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