XML 52 R40.htm IDEA: XBRL DOCUMENT v3.20.2

Investments - Additional Information (Detail)	3 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($) security	Sep. 30, 2020 USD ($) security	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Schedule of Debt and Equity Securities [Line Items]
Principal amount of bonds and certificates of deposit	$ 281,100,000	$ 281,100,000
Securities Exceeding 10% of Shareholders' Equity	0	0	$ 0	$ 0
Non-Income Producing Securities	0	0
Open reverse repurchase commitments	0	0	400,000,000.0	0
Securities Sold under Agreements to Repurchase	$ 0	$ 0	$ 0	$ 0
Debt Securities, Available-for-sale, Unrealized Loss Position, Positions Downgraded | security	4	4
Combined fair value of securities	$ 47,500,000	$ 47,500,000
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss, Downgrades in Period	1,500,000	1,500,000
Debt Securities, Available-for-sale, Allowance for Credit Loss, Not Previously Recorded		0
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 0	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Writeoff		$ 0
Percent Change in Investment Income	12.00%	8.00%
Percent Change in Book Yield	(25.00%)	(21.00%)
Investment Portfolio Duration		3 years	2 years 10 months 24 days
Corporate debt securities
Schedule of Debt and Equity Securities [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Positions Downgraded | security	2	2
Commercial mortgage-backed securities
Schedule of Debt and Equity Securities [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Positions Upgraded | security	0	0
Residential mortgage-backed securities
Schedule of Debt and Equity Securities [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Positions Downgraded | security	2	2

X

- Definition

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.

+ References

No definition available.

+ Details

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

X

- Definition

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.

+ References

No definition available.

+ Details

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

X

- Definition

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.

+ References

No definition available.

+ Details

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

X

- Definition

Number of investments in debt securities with a credit rating upgrade 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

+ References

No definition available.

+ Details

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

X

- Definition

Duration of the total investment portfolio, a measure of the portfolio's exposure to changes in interest rates, shown in years.

+ References

No definition available.

+ Details

Name:	pgr_InvestmentPortfolioDuration
Namespace Prefix:	pgr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

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

+ References

No definition available.

+ Details

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

X

- Definition

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.

+ References

No definition available.

+ Details

Name:	pgr_PercentChangeinBookYield
Namespace Prefix:	pgr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

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

+ References

No definition available.

+ Details

Name:	pgr_PercentChangeinInvestmentIncome
Namespace Prefix:	pgr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

[Line Items] for Tabular disclosure of the debt and equity securities, reconciled from cost basis to fair value.

+ References

No definition available.

+ Details

Name:	pgr_ScheduleofDebtandEquitySecuritiesLineItems
Namespace Prefix:	pgr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

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.

+ References

No definition available.

+ Details

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

X

- Definition

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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922900-210455

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 9
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922900-210455

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121558606&loc=SL82898722-210454

+ Details

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

X

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922900-210455

+ Details

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

X

- Definition

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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 9
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922900-210455

+ Details

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

X

- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.8,17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

X

- Definition

The carrying value of securities purchased to be resold in reverse repurchase transactions as of the balance sheet date.

+ References

No definition available.

+ Details

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

X

- Definition

Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=49176635&loc=d3e9760-107771

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(1))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(m)(1)(a)(i))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

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

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: