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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 | 6 Months Ended
--- | --- | ---
Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2019 | Jun. 30, 2018
Derivative [Line Items] |  |  |  |
Gain (loss) recognized in Accumulated other comprehensive loss | $ (12) |  | $ (8) |
Gain (loss) recognized in Accumulated other comprehensive loss |  | $ (25) |  | $ (11)
Derivative gains (losses) reclassified from accumulated other comprehensive loss | (3) |  | (8) |
Derivative gain (loss) reclassified from accumulated OCI into income, effective portion, net |  | (2) |  | (6)
Revenue |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative gains (losses) reclassified from accumulated other comprehensive loss | (3) |  | (7) |
Derivative gain (loss) reclassified from accumulated OCI into income, effective portion, net |  | 0 |  | 0
Compensation and benefits |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative gains (losses) reclassified from accumulated other comprehensive loss | 0 |  | 0 |
Derivative gain (loss) reclassified from accumulated OCI into income, effective portion, net |  | 0 |  | 1
Other general expenses |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative gains (losses) reclassified from accumulated other comprehensive loss | 0 |  | 0 |
Derivative gain (loss) reclassified from accumulated OCI into income, effective portion, net |  | (1) |  | (2)
Interest expense |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative gains (losses) reclassified from accumulated other comprehensive loss | 0 |  | (1) |
Derivative gain (loss) reclassified from accumulated OCI into income, effective portion, net |  | 0 |  | (1)
Other income (expense) (1) |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative gains (losses) reclassified from accumulated other comprehensive loss | $ 0 |  | $ 0 |
Derivative gain (loss) reclassified from accumulated OCI into income, effective portion, net |  | $ (1) |  | $ (4)

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- Definition The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
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- Definition Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109974929&loc=SL110061190-113977 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580 + Details
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