Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues
Net premiums earned		$ 4,995.8	$ 4,513.5	$ 9,662.1	$ 8,915.8
Period over prior year period percent change in net premiums earned		11.00%		8.00%
Investment income		$ 113.3	99.2	$ 218.4	202.5
Period over prior year period percent change in investment income		14.00%		8.00%
Other-than-temporary impairment (OTTI) losses:
Net impairment losses recognized in earnings		$ (1.7)	0.0	$ (9.6)	0.0
Net realized gains (losses) on securities		$ 77.7	40.4	$ 118.6	159.8
Period over prior year period percent change in net realized gains (losses) on securities		92.00%		(26.00%)
Total net realized gains (losses) on securities		$ 76.0	40.4	$ 109.0	159.8
Period over prior year period percent change in total net realized gains (losses) on securities		88.00%		(32.00%)
Fees and other revenues		$ 74.9	74.4	$ 148.6	147.2
Period over prior year period percent change in fees and other revenues		1.00%		1.00%
Service revenues		$ 23.3	14.0	$ 40.5	23.8
Period over prior year period percent change in service revenues		66.00%		70.00%
Total revenues		$ 5,283.3	4,741.5	$ 10,178.6	9,449.1
Period over prior year period percent change in total revenues		11.00%		8.00%
Expenses
Losses and loss adjustment expenses		$ 3,617.2	3,269.1	$ 6,985.8	6,475.0
Period over prior year period percent change in losses and loss adjustment expenses		11.00%		8.00%
Policy acquisition costs		$ 417.3	374.8	$ 796.7	743.8
Period over prior year period percent change in policy acquisition costs		11.00%		7.00%
Other underwriting expenses		$ 662.4	611.7	$ 1,312.8	1,222.1
Period over prior year period percent change in other underwriting expenses		8.00%		7.00%
Investment expenses		$ 5.7	6.0	$ 11.0	10.1
Period over prior year period percent change in investment expenses		(5.00%)		9.00%
Service expenses		$ 20.5	12.9	$ 36.4	22.6
Period over prior year period percent change in service expenses		59.00%		61.00%
Interest expense		$ 34.9	29.6	$ 67.4	56.3
Period over prior year period percent change in interest expense		18.00%		20.00%
Total expenses		$ 4,758.0	4,304.1	$ 9,210.1	8,529.9
Period over prior year period percent change in total expenses		11.00%		8.00%
Net Income
Income before income taxes		$ 525.3	437.4	$ 968.5	919.2
Period over prior year period percent change in income before income taxes		20.00%		5.00%
Provision for income taxes		$ 156.8	144.0	$ 304.4	304.5
Period over prior year period percent change in provision for income taxes		9.00%		0.00%
Period over prior year period percent change in net income		26.00%		8.00%
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		$ 368.5	293.4	$ 664.1	614.7
Net Income (Loss) Attributable to Noncontrolling Interest		5.2	0.0	5.2	0.0
Net Income (Loss) Attributable to Parent		$ 363.3	293.4	$ 658.9	614.7
Period over Prior Year Period Percent Change Net Income Attributable to Parent		24.00%		7.00%
Net unrealized gains (losses) on securities:
Total net unrealized gains (losses) on securities		$ (149.8)	88.4	$ (114.4)	88.3
Period over prior year period percent change in total net unrealized gains (losses) on securities		(269.00%)		(230.00%)
Net unrealized gains (losses) on forecasted transactions		$ (0.3)	(1.3)	$ (9.0)	(1.6)
Period over prior year period percent change in net unrealized gains on forecasted transactions		(77.00%)		463.00%
Foreign currency translation adjustment		$ 0.0	0.5	$ (0.5)	0.5
Period over prior year period percent change in foreign currency translation adjustment		(100.00%)		(200.00%)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ (150.1)	87.6	$ (123.9)	87.2
Period over prior year period percent change in other comprehensive income (loss)		(271.00%)		(242.00%)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		$ 2.8	0.0	$ 2.8	0.0
Comprehensive income		$ 216.0	$ 381.0	$ 537.8	$ 701.9
Period over prior year period percent change in comprehensive income		(43.00%)		(23.00%)
Computation of Net Income Per Share
Average shares outstanding - Basic (shares)		585.7	591.2	586.6	592.6
Period over prior year period percent change in average shares outstanding - basic		(1.00%)		(1.00%)
Net effect of dilutive stock-based compensation (shares)		3.8	4.3	3.7	4.0
Period over prior year period percent change in net effect of dilutive stock-based compensation		(12.00%)		(8.00%)
Total equivalent shares - Diluted (shares)		589.5	595.5	590.3	596.6
Period over prior year period percent change in total equivalent shares - diluted		(1.00%)		(1.00%)
Basic: Net income per share (USD per share)		$ 0.62	$ 0.50	$ 1.12	$ 1.04
Period over prior year period percent change in basic: net income per share		25.00%		8.00%
Diluted: Net income per share (USD per share)		$ 0.62	0.49	$ 1.12	1.03
Period over prior year period percent change in diluted: net income per share		25.00%		8.00%
Dividends declared per share (USD per share)	[1]	$ 0	$ 0	$ 0	$ 0

[1] 1Progressive maintains an annual dividend program. See Note 8 - Dividends for further discussion.See notes to consolidated financial statements.