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Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies (Details) - USD ($) $ in Millions |  | 3 Months Ended | 6 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jan. 01, 2020 | Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Mar. 31, 2020 | Dec. 31, 2019 | Mar. 31, 2019 | Jan. 01, 2019 | Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |  |  |
Equity | $ (13,399) | $ (13,826) | $ (14,316) | $ (13,826) | $ (14,316) | $ (13,519) | $ (14,416) | $ (13,699) | $ (13,266) | $ (13,268)
Allowance for Loan and Lease Losses, Adjustments, Other |  | $ 0 | (1) | $ (1) | 0 |  |  |  |  |
Phase-in of capital impact of Accounting Standards Update 2016-13 |  | 25.00% |  | 25.00% |  |  |  |  |  |
CECL scaling factor |  | 25.00% |  | 25.00% |  |  |  |  |  |
Accounting Standards Update 2016-13 |  |  |  |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |  |  |
Equity | 1,017 |  |  |  |  |  |  |  |  |
Allowance for Loan and Lease Losses, Adjustments, Other | 1,300 |  |  |  |  |  |  |  |  |
Phase-in of capital impact of Accounting Standards Update 2016-13 |  | 25.00% |  | 25.00% |  |  |  |  |  |
CECL scaling factor |  | 25.00% |  | 25.00% |  |  |  |  |  |
Accumulated Deficit |  |  |  |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |  |  |
Equity | 5,074 | $ 5,296 | $ 4,682 | $ 5,296 | $ 4,682 | $ 5,465 | $ 4,057 | $ 5,195 | $ 5,499 | $ 5,489
Accumulated Deficit | Accounting Standards Update 2016-13 |  |  |  |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |  |  |
Equity | $ 1,017 |  |  |  |  |  |  |  |  |

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- Definition Amount of other addition (reduction) in allowance reserve for credit loss. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5212-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 4.E) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(31)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(30)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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