Employee Benefit Plan, Description of Plan (Details) - EBP 002 - USD ($)	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
EBP, Description of Plan [Line Items]
EBP, Employer Contribution, Matching Percentage	100.00%
EBP, Participant Contribution, Automatic, Deferral Rate	6.00%
Automatic Deferral Rate Increase	1.00%
Maximum Automatic Deferral Rate Increase	10.00%
Rollover contributions	$ 9,274,563	$ 7,675,947
Maximum Loan Amount	$ 50,000
Maximum account balance for loan (percent)	50.00%
EBP, Participant Loan, Basis Spread On Variable Rate	1.00%
Forfeited Nonvested Account Balance	$ 46,476	18,685
Forfeitures used to reduce employer contributions	$ 854,309	$ 938,800
EBP, Employer Contribution, Participant Compensation Matched, Percentage	6.00%
Minimum
EBP, Description of Plan [Line Items]
Participant Loan Interest Rate	4.25%
Maximum
EBP, Description of Plan [Line Items]
Participant Loan Interest Rate	9.50%

EBP, Participant Loan, Basis Spread On Variable Rate

No definition available.

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Period Type:	duration

- Definition

Percentage of increase in eligible compensation contributed for participant automatically enrolled until changed by employee in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

No definition available.

+ Details

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Namespace Prefix:	cinf_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of maximum increase in eligible compensation contributed for participant automatically enrolled until changed by employee in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

No definition available.

+ Details

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Namespace Prefix:	cinf_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase in net asset available for benefit from contribution transferred from another qualified plan or from individual retirement account of participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Excludes contribution for participant transmitted by employer of participant in EBP.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(4)(a)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(4)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 4: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule III))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 5: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 50
-Paragraph 2B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477783/962-325-50-2B

Reference 6: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477063/962-205-45-7

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of participant compensation eligible for employer matching contribution for participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of plan asset, in forfeited nonvested account, no longer allocated to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of decrease in forfeited nonvested account of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) from employer contribution.

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow to total participant account balance.

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest rate on participant loan in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (1)(i)(D)
-Publisher DOL-EBSA

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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- Details

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