XML 75 R61.htm IDEA: XBRL DOCUMENT
v3.21.2

Fair Value Measurements (Summary Of Quantitative Information About Level 3 Fair Value Measurements) (Details) - Mortgage Servicing Rights [Member] - Discounted Cash Flow [Member] $ in Millions | Jun. 30, 2021 USD ($) | Dec. 31, 2020 USD ($)
--- | --- | ---
Level 3 [Member] |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |
Assets, Fair Value Disclosure | $ 392 | [1] | $ 296 | [2]
Recurring Fair Value Measurements [Member] | Minimum [Member] |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |
Weighted Average CPR | 0.066 |  | 0.081 |
Option-Adjusted Spread | 4.80% |  | 4.80% |
Recurring Fair Value Measurements [Member] | Maximum [Member] |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |
Weighted Average CPR | 0.222 |  | 0.312 |
Option-Adjusted Spread | 9.40% |  | 9.50% |
Recurring Fair Value Measurements [Member] | Weighted Average [Member] |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |
Weighted Average CPR | 0.105 |  | 0.156 |
Option-Adjusted Spread | 5.70% |  | 5.60% |
[1] | See Note 4 for additional disclosures related to assumptions used in the fair value calculation for residential mortgage servicing rights.
[2] | See Note 7 to the consolidated financial statements of the Annual Report on Form 10-K for the year ended December 31, 2020 for additional disclosures related to assumptions used in the fair value calculation for residential mortgage servicing rights.

X
- Definition Option-Adjusted Spread + References No definition available. + Details
Name: | rf_OptionAdjustedSpread
Namespace Prefix: | rf_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of input used to measure servicing asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_ServicingAssetMeasurementInput
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_ServicingContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=rf_DiscountedCashFlowMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |