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Asset Quality - Summary of Post-Modification Outstanding Recorded Investment TDRs (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018
Financing Receivables, Modifications, Rollforward [Roll Forward] |  |
Balance at beginning of the period | $ 399 | $ 317
Additions | 112 | 228
Payments | (145) | (110)
Charge-offs | (19) | (36)
Balance at end of period | $ 347 | $ 399

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- Definition Financing Receivable, Modifications, Additions + References No definition available. + Details
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- Definition Financing Receivable, Modifications, Payments + References No definition available. + Details
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- Definition Financing Receivables, Modifications, Rollforward [Roll Forward] + References No definition available. + Details
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- Definition Amount of financing receivable modified as troubled debt restructuring. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18845-111554 + Details
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- Definition Reflects the amount of the write-down related to a troubled debt restructuring. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18845-111554 + Details
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