Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues
Premiums	$ 1,174.7	$ 1,090.8	$ 2,337.7	$ 2,185.1
Net investment income	67.0	67.9	134.0	135.2
Net realized investment gains (losses):
Net realized gains from sales and other	22.3	14.8	26.7	23.4
Net other-than-temporary impairment losses on investments recognized in earnings	(0.1)	(1.1)	(0.1)	(1.6)
Total net realized investment gains	22.2	13.7	26.6	21.8
Fees and other income	9.1	10.2	18.6	20.8
Total revenues	1,273.0	1,182.6	2,516.9	2,362.9
Losses and expenses
Losses and loss adjustment expenses	725.5	692.1	1,476.0	1,375.5
Amortization of deferred acquisition costs	259.6	232.7	513.3	475.2
Interest expense	16.3	17.4	32.6	32.1
Other operating expenses	163.9	174.5	315.2	325.3
Total losses and expenses	1,165.3	1,116.7	2,337.1	2,208.1
Income before income taxes	107.7	65.9	179.8	154.8
Income tax expense:
Current	(1.6)	(0.5)	7.6	3.5
Deferred	26.8	13.3	35.0	31.8
Total income tax expense	25.2	12.8	42.6	35.3
Income from continuing operations	82.5	53.1	137.2	119.5
Net gain from discontinued operations (net of tax benefit (expense) of $0.1 and $(0.1) for the three months ended June 30, 2014 and June 30, 2013 and $0.2 for the six months ended June 30, 2014)	0.1	0.3		0.1
Net income	$ 82.6	$ 53.4	$ 137.2	$ 119.6
Basic:
Income from continuing operations	$ 1.87	$ 1.21	$ 3.12	$ 2.70
Net gain from discontinued operations	$ 0.01
Net income per share	$ 1.88	$ 1.21	$ 3.12	$ 2.70
Weighted average shares outstanding	44.1	44.0	44.0	44.3
Diluted:
Income from continuing operations	$ 1.84	$ 1.19	$ 3.06	$ 2.65
Net gain from discontinued operations				$ 0.01
Net income per share	$ 1.84	$ 1.19	$ 3.06	$ 2.66
Weighted average shares outstanding	44.9	44.8	44.8	45.0