XML 239 R93.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Derivatives and Hedging Activities - Cumulative Basis Adjustments on Fair Value Hedges (Details) - USD ($) | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Derivatives, Fair Value [Line Items] |  |
Certificate of deposit ($100,000 or more) | $ 100,000 | $ 100,000
Long-term Debt [Member] | Interest Rate [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Carrying amount of hedged item | 8,408,000,000 | 9,363,000,000
Hedge accounting basis adjustment | 240,000,000 | (6,000,000)
Certificates of Deposit [Member] | Interest Rate [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Certificate of deposit ($100,000 or more) | 100,000 | 100,000
Carrying amount of hedged item | 0 | 343,000,000
Hedge accounting basis adjustment | 0 | (1,000,000)
Bank Time Deposits [Member] | Interest Rate [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Carrying amount of hedged item | 0 | 178,000,000
Hedge accounting basis adjustment | 0 | 0
Not Designated as Hedging Instrument [Member] | Long-term Debt [Member] | Interest Rate [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Hedge accounting basis adjustment | $ (9,000,000) | $ (10,000,000)

X
- Definition Aggregate amount of certificates of deposit. + References No definition available. + Details
Name: | key_AggregateAmountOfCertificatesOfDeposit
Namespace Prefix: | key_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_DerivativesFairValueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4EE -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109999712-113959 + Details
Name: | us-gaap_HedgedAssetFairValueHedgeCumulativeIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of liability hedged in fair value hedging relationship. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4EE -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109999712-113959 + Details
Name: | us-gaap_HedgedLiabilityFairValueHedge
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_LongTermDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_BankTimeDepositsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |