CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues
Premiums	$ 4,239.1	$ 3,598.6	$ 2,841.0
Net investment income	276.6	258.2	247.2
Net realized investment gains (losses):
Net realized gains from sales and other	31.4	35.0	43.6
Net other - than - temporary impairment losses on investments recognized in earnings	(7.8)	(6.9)	(13.9)
Total net realized investment gains	23.6	28.1	29.7
Fees and other income	51.4	46.7	34.3
Total revenues	4,590.7	3,931.6	3,152.2
Losses and expenses
Losses and loss adjustment expenses	2,974.4	2,550.8	1,856.3
Policy acquisition expenses	938.1	778.9	600.8
Interest expense	61.9	55.0	44.3
Other operating expenses	587.6	525.3	445.2
Total expenses	4,562.0	3,910.0	2,946.6
Income (loss) before income taxes	28.7	21.6	205.6
Income tax expense (benefit):
Current	18.4	(0.6)	5.7
Deferred	(35.8)	(9.3)	50.3
Total income tax expense (benefit)	(17.4)	(9.9)	56.0
Income from continuing operations	46.1	31.5	149.6
Net gain from discontinued operations (net of income tax benefit of $0.5, $2.5 and $0.2 in 2012, 2011 and 2010)	9.8	5.2	1.6
Net income	$ 55.9	$ 36.7	$ 151.2
Basic:
Income from continuing operations	$ 1.03	$ 0.70	$ 3.28
Net gain from discontinued operations	$ 0.22	$ 0.11	$ 0.04
Net income per share	$ 1.25	$ 0.81	$ 3.32
Weighted average shares outstanding	44.7	45.2	45.6
Diluted:
Income from continuing operations	$ 1.02	$ 0.69	$ 3.23
Net gain from discontinued operations	$ 0.21	$ 0.11	$ 0.04
Net income per share	$ 1.23	$ 0.80	$ 3.27
Weighted average shares outstanding	45.3	45.8	46.3