Business Segments - Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 segments	Jun. 30, 2012
Segment Reporting Information [Line Items]
Number of Operating Segments			4
Earned Premiums	$ 512.8	$ 529.8	$ 1,022.7	$ 1,059.0
Net Investment Income	74.6	75.2	155.4	152.6
Other Income	0.2	0.2	0.4	0.4
Total Revenues	588.9	608.9	1,204.8	1,220.1
Net Realized Gains on Sales of Investments	2.3	4.1	29.2	9.0
Net Impairment Losses Recognized in Earnings	(1.0)	(0.4)	(2.9)	(0.9)
Segment Operating Profit (Loss)	45.1	(7.2)	104.7	38.8
Income (Loss) from Continuing Operations before Income Taxes	46.4	(3.5)	131.0	46.9
Segment Net Operating Income (Loss)	31.7	(0.8)	74.0	32.6
Income from Continuing Operations	32.5	1.6	91.1	37.9
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	584.3	600.0	1,172.5	1,204.8
Segment Operating Profit (Loss)	56.8	0.1	128.9	58.1
Segment Net Operating Income (Loss)	39.4	3.5	89.6	44.5
Kemper Preferred [Member]
Segment Reporting Information [Line Items]
Earned Premiums	221.5	218.0	440.7	433.0
Net Investment Income	13.2	11.9	28.2	22.8
Other Income	0	0.1	0.1	0.2
Total Revenues	234.7	230.0	469.0	456.0
Segment Operating Profit (Loss)	13.7	(19.1)	40.1	(6.0)
Segment Net Operating Income (Loss)	10.5	(10.3)	29.3	0.1
Kemper Specialty [Member]
Segment Reporting Information [Line Items]
Earned Premiums	100.6	106.6	199.8	213.4
Net Investment Income	5.1	4.7	11.4	9.9
Other Income	0.1	0.1	0.2	0.1
Total Revenues	105.8	111.4	211.4	223.4
Segment Operating Profit (Loss)	0.3	(5.6)	4.5	(0.7)
Segment Net Operating Income (Loss)	0.7	(2.8)	4.2	1.3
Kemper Direct [Member]
Segment Reporting Information [Line Items]
Earned Premiums	31.8	43.9	65.5	90.9
Net Investment Income	3.2	3.7	7.0	7.3
Total Revenues	35.0	47.6	72.5	98.2
Segment Operating Profit (Loss)	11.6	(5.5)	21.2	(8.5)
Segment Net Operating Income (Loss)	7.9	(2.9)	14.6	(4.2)
Life and Health Insurance [Member]
Segment Reporting Information [Line Items]
Earned Premiums	158.9	161.3	316.7	321.7
Net Investment Income	49.8	49.7	102.8	105.4
Other Income	0.1	0	0.1	0.1
Total Revenues	208.8	211.0	419.6	427.2
Segment Operating Profit (Loss)	31.2	30.3	63.1	73.3
Segment Net Operating Income (Loss)	20.3	19.5	41.5	47.3
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Other Income	3.3	5.2	6.0	7.2
Segment Operating Profit (Loss)	(11.7)	(7.3)	(24.2)	(19.3)
Segment Net Operating Income (Loss)	(7.7)	(4.3)	(15.6)	(11.9)
Net Realized Gains (Losses) on Sales of Investments, Net of Tax	1.5	2.7	19.0	5.9
Net Impairment Losses Recognized in Earnings, Net of Tax	$ (0.7)	$ (0.3)	$ (1.9)	$ (0.6)