The percentage of securities with prices quoted by vendors, calculated based on the total Fair Value in the hierarchy level (Level 1, Level 2, or Level 3).

No definition available.

Name:	pgr_VendorQuotedPricesPercentofFVHierarchyLevel
Namespace Prefix:	pgr_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Fair Value - Additional Information (Detail)	Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2024
Fair Value, Inputs, Level 1
Fair Value Measurements [Line Items]
Vendor quoted prices, percent of FV hierarchy level	93.00%	93.00%
Fair Value, Inputs, Level 2
Fair Value Measurements [Line Items]
Vendor quoted prices, percent of FV hierarchy level	99.00%	100.00%	100.00%