Name:	pgr_DebtSecuritiesAvailableForSaleUnrealizedLossPositionIssuersDowngraded
Namespace Prefix:	pgr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Amount of accumulated unrealized loss on debt securities with credit rating downgrades during the period. These securities are measured at fair value with changes in fair value recognized in other comprehensive income (available-for-sale), in an unrealized loss position, without a credit loss allowance.

No definition available.

Name:	pgr_DebtSecuritiesAvailableforsaleUnrealizedLossPositionAccumulatedLossDowngradesinPeriod
Namespace Prefix:	pgr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of investment in debt securities with a credit rating downgrade during the period. These securities are measure at fair value with the changes in fair value recognized in other comprehensive income (available-for-sale), in an unrealized loss position without an allowance for credit losses.

No definition available.

Name:	pgr_DebtSecuritiesAvailableforsaleUnrealizedLossPositionDowngradedinPeriod
Namespace Prefix:	pgr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Number of investments in debt securities with a credit rating downgrade during the period. These securities are measured at fair value with the changes in fair value recognized in other comprehensive income (available-for-sale), in an unrealized loss position, without an allowance for credit losses.

No definition available.

Name:	pgr_DebtSecuritiesAvailableforsaleUnrealizedLossPositionPositionsDowngraded
Namespace Prefix:	pgr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Fair value of fixed-maturity securities that were non-income producing during the preceding 12 months.

No definition available.

Name:	pgr_NonIncomeProducingSecurities
Namespace Prefix:	pgr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Change in the annualized weighted average book yield on securities held in the portfolio. Reflected as a percentage change compared to the same period in the prior year.

No definition available.

Name:	pgr_PercentChangeinBookYield
Namespace Prefix:	pgr_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

Current year increase (decrease) in investment income before expenses. Reflected as a percentage change compared to the same period in the prior year.

No definition available.

Name:	pgr_PercentChangeinInvestmentIncome
Namespace Prefix:	pgr_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

Number of positions for which a portion of the prior impairment was recovered during the period as a result of litigation settlements. The original positions and impairments were recorded as part of other assets on the Balance Sheets

No definition available.

Name:	pgr_RecoveryOfImpairmentOtherAssetsNumberOfPositions
Namespace Prefix:	pgr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Securities held in the portfolio with a single issuer for which the aggregate cost or fair value exceeds 10% of shareholders' equity. Excludes U.S. Government Obligations.

No definition available.

Name:	pgr_SecuritiesExceeding10ofShareholdersEquity
Namespace Prefix:	pgr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

Name:	us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of expense for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), for which no credit loss was previously recorded.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

Name:	us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of writeoff of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

Name:	us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The carrying amount of the asset transferred to a third party to serve as a deposit, which typically serves as security against failure by the transferor to perform under terms of an agreement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Name:	us-gaap_DepositAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.