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Commitments, Contingencies, Guarantees, and Others - Litigation (Details) $ in Millions	1 Months Ended		12 Months Ended
	Jan. 31, 2021 USD ($)	Oct. 31, 2018 USD ($)	Dec. 31, 2020 USD ($) claim
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss			$ 200
Anti-money laundering
Loss Contingencies [Line Items]
Litigation settlement paid		$ 100
Anti-money laundering | Subsequent Event
Loss Contingencies [Line Items]
Litigation settlement paid	$ 390
Litigation settlement paid from reserve	$ 290
Cybersecurity Incident [Member]
Loss Contingencies [Line Items]
Number of consumer class action cases filed for Cybersecurity Incident | claim			73
Number of consumer class action cases currently pending for cybersecurity incident | claim			29
Penalty Paid to the US Treasury			$ 80
Pending litigation | Interchange litigation
Loss Contingencies [Line Items]
Litigation settlement, attributable to reporting entity and third party			$ 5,500
United States | Cybersecurity Incident [Member]
Loss Contingencies [Line Items]
Number of consumer class action cases filed for Cybersecurity Incident | claim			61
Canada | Cybersecurity Incident [Member]
Loss Contingencies [Line Items]
Number of consumer class action cases filed for Cybersecurity Incident | claim			12

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Number of consumer class action cases filed for Cybersecurity Incident

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12021-110248

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