Consolidated Statements of Comprehensive Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Revenues
Net premiums earned	$ 4,303.0		$ 4,054.8		$ 12,759.3		$ 11,912.4
Period over prior year period percent change in net premiums earned	6.00%				7.00%
Investment income	107.4		109.0		310.1		336.2
Period over prior year period percent change in investment income	(1.00%)				(8.00%)
Other-than-temporary impairment (OTTI) losses:
Total OTTI losses	(1.9)		(0.4)		(3.6)		(6.0)
Period over prior year period percent change in total OTTI losses	375.00%				(40.00%)
Non-credit losses, net of credit losses recognized on previously recorded non-credit OTTI losses	0		0		(0.1)		(0.7)
Period over prior year period percent change in non-credit losses, net of credit losses recognized on previously recorded non-credit OTTI losses					(86.00%)
Net impairment losses recognized in earnings	(1.9)		(0.4)		(3.7)		(6.7)
Period over prior year period percent change in net impairment losses recognized in earnings	375.00%				(45.00%)
Net realized gains (losses) on securities	29.8		172.3		245.1		251.4
Period over prior year period percent change in net realized gains (losses) on securities	(83.00%)				(3.00%)
Total net realized gains (losses) on securities	27.9		171.9		241.4		244.7
Period over prior year period percent change in total net realized gains (losses) on securities	(84.00%)				(1.00%)
Fees and other revenues	76.0		78.4		215.3		213.5
Period over prior year period percent change in fees and other revenues	(3.00%)				1.00%
Service revenues	11.3		9.9		30.3		28.3
Period over prior year period percent change in service revenues	14.00%				7.00%
Gains (losses) on extinguishment of debt	(4.3)		(0.1)		(4.3)		(1.8)
Period over prior year period percent change in gains (losses) on extinguishment of debt	4200.00%				139.00%
Total revenues	4,521.3		4,423.9		13,552.1		12,733.3
Period over prior year period percent change in total revenues	2.00%				6.00%
Expenses
Losses and loss adjustment expenses	3,164.2		3,068.2		9,266.7		8,874.3
Period over prior year period percent change in losses and loss adjustment expenses	3.00%				4.00%
Policy acquisition costs	363.1		357.3		1,086.0		1,081.4
Period over prior year period percent change in policy acquisition costs	2.00%				0.00%
Other underwriting expenses	602.3		542.5		1,769.0		1,681.2
Period over prior year period percent change in other underwriting expenses	11.00%				5.00%
Investment expenses	5.2		3.3		14.5		11.3
Period over prior year period percent change in investment expenses	58.00%				28.00%
Service expenses	11.1		9.6		30.1		27.7
Period over prior year period percent change in service expenses	16.00%				9.00%
Interest expense	30.4		30.6		91.4		93.2
Period over prior year period percent change in interest expense	(1.00%)				(2.00%)
Total expenses	4,176.3		4,011.5		12,257.7		11,769.1
Period over prior year period percent change in total expenses	4.00%				4.00%
Net Income
Income before income taxes	345.0		412.4		1,294.4		964.2
Period over prior year period percent change in income before income taxes	(16.00%)				34.00%
Provision for income taxes	112.6		135.4		428.8		311.0
Period over prior year period percent change in provision for income taxes	(17.00%)				38.00%
Net income	232.4		277.0		865.6		653.2
Period over prior year period percent change in net income	(16.00%)				33.00%
Net unrealized gains (losses) on securities:
Net non-credit related OTTI losses, adjusted for valuation changes	0		1.7		0.3		4.8
Period over prior year period percent change in net non-credit related OTTI losses, adjusted for valuation changes					(94.00%)
Other net unrealized gains (losses) on securities	57.8		60.6		2.4		209.0
Period over prior year period percent change in other net unrealized gains (losses) on securities	(5.00%)				(99.00%)
Total net unrealized gains (losses) on securities	57.8		62.3		2.7		213.8
Period over prior year period percent change in total net unrealized gains (losses) on securities	(7.00%)				(99.00%)
Net unrealized gains on forecasted transactions	(0.9)		(0.3)		(1.6)		(1.5)
Period over prior year period percent change in net unrealized gains on forecasted transactions	200.00%				7.00%
Foreign currency translation adjustment	(0.2)		0.4		(1.2)		0.3
Other comprehensive income (loss)	56.7		62.4		(0.1)		212.6
Period over prior year period percent change in other comprehensive income (loss)	(9.00%)
Comprehensive income	$ 289.1		$ 339.4		$ 865.5		$ 865.8
Period over prior year period percent change in comprehensive income	(15.00%)				0.00%
Computation of Net Income Per Share
Average shares outstanding - Basic (shares)	598.9		601.9		599.7		604.3
Period over prior year period percent change in average shares outstanding - basic	0.00%				(1.00%)
Net effect of dilutive stock-based compensation (shares)	4.6		4.6		4.2		4.2
Period over prior year period percent change in net effect of dilutive stock-based compensation	0.00%				0.00%
Total equivalent shares - Diluted (shares)	603.5		606.5		603.9		608.5
Period over prior year period percent change in total equivalent shares - diluted	0.00%				(1.00%)
Basic: Net income per share (USD per share)	$ 0.39		$ 0.46		$ 1.44		$ 1.08
Period over prior year period percent change in basic: net income per share	(16.00%)				34.00%
Diluted: Net income per share (USD per share)	$ 0.39		$ 0.46		$ 1.43		$ 1.07
Period over prior year period percent change in diluted: net income per share	(16.00%)				34.00%
Dividends declared per share (USD per share)	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]

[1] Progressive maintains an annual dividend program. See Note 8 - Dividends for further discussion.