Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues
Net premiums earned	$ 9,648.6	$ 8,824.7	$ 19,079.3	$ 17,284.5
Investment income	243.8	261.3	485.0	514.2
Net realized gains (losses) on securities:
Net realized gains (losses) on security sales	260.0	67.5	575.2	113.6
Net holding period gains (losses) on securities	630.8	112.4	(238.0)	505.1
Net impairment losses recognized in earnings	0.0	0.0	0.0	(24.3)
Total net realized gains (losses) on securities	890.8	179.9	337.2	594.4
Fees and other revenues	129.5	134.8	283.0	265.0
Service revenues	59.0	50.0	110.6	92.6
Total revenues	10,971.7	9,450.7	20,295.1	18,750.7
Expenses
Losses and loss adjustment expenses	5,321.4	6,138.1	11,476.6	11,897.1
Policy acquisition costs	795.5	738.6	1,578.3	1,449.2
Other underwriting expenses	1,438.9	1,231.5	2,848.8	2,402.7
Policyholder credit expense	1,033.4	0.0	1,033.4	0.0
Investment expenses	4.5	6.2	9.8	12.4
Service expenses	52.8	45.3	100.3	83.4
Interest expense	56.4	47.4	104.4	94.8
Total expenses	8,702.9	8,207.1	17,151.6	15,939.6
Net Income
Income before income taxes	2,268.8	1,243.6	3,143.5	2,811.1
Provision for income taxes	478.4	264.6	654.0	749.3
Net income	1,790.4	979.0	2,489.5	2,061.8
Net (income) loss attributable to noncontrolling interest (NCI)	0.0	0.4	0.0	(4.0)
Net income attributable to Progressive	1,790.4	979.4	2,489.5	2,057.8
Other Comprehensive Income (Loss)
Total net unrealized gains (losses) on fixed-maturity securities	567.4	277.4	630.2	578.5
Net unrealized losses on forecasted transactions	0.2	0.2	0.4	0.4
Other comprehensive income (loss)	567.6	277.6	630.6	578.9
Other comprehensive (income) loss attributable to NCI	0.0	(2.6)	0.0	(4.9)
Comprehensive income attributable to Progressive	2,358.0	1,254.4	3,120.1	2,631.8
Computation of Earnings Per Common Share
Net income attributable to Progressive	1,790.4	979.4	2,489.5	2,057.8
Less: Preferred share dividends	6.7	6.7	13.4	13.4
Net income available to common shareholders	$ 1,783.7	$ 972.7	$ 2,476.1	$ 2,044.4
Average common shares outstanding - Basic	584.8	583.6	584.8	583.5
Net effect of dilutive stock-based compensation	2.4	3.3	2.3	3.2
Total average equivalent common shares - Diluted	587.2	586.9	587.1	586.7
Basic: Earnings per common share	$ 3.05	$ 1.67	$ 4.23	$ 3.50
Diluted: Earnings per common share	$ 3.04	$ 1.66	$ 4.22	$ 3.48