XML 83 R40.htm IDEA: XBRL DOCUMENT
v3.25.4

Summary of Significant Accounting Policies (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2025
Accounting Policies [Abstract] |
Schedule of New Accounting Pronouncements and Changes in Accounting Principles | Accounting Guidance Adopted in 2025
Standard | Date of Adoption | Description | Effect on Financial Statements or Other Significant Matters
ASU 2023-09 Income Taxes (Topic 740) | Annual periods beginning January 1, 2025 Early adoption is permitted. | This guidance requires certain tax disclosures related to rate reconciliation and income taxes paid. The guidance should be applied on a prospective or retrospective basis. | The guidance did not have a material impact on Key’s disclosures. See Note 13 (“Income Taxes”) for enhanced disclosures.

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-3 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-1 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 105 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 9 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479343/105-10-65-9 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 805 -SubTopic 60 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476176/805-60-65-1 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 270 -SubTopic 10 -Section 45 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482989/270-10-45-12 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 270 -SubTopic 10 -Section 45 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482989/270-10-45-13 + Details
Name: | us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration