Business Segments - Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 segments	Sep. 30, 2012
Segment Reporting Information [Line Items]
Number of Operating Segments			4
Earned Premiums	$ 507.5	$ 527.3	$ 1,530.2	$ 1,586.3
Net Investment Income	82.4	70.4	237.8	223.0
Other Income	0.1	0.2	0.5	0.6
Total Revenues	635.7	645.6	1,840.5	1,865.7
Net Realized Gains on Sales of Investments	49.1	50.9	78.3	59.9
Segment Operating Profit (Loss)	56.3	33.8	161.0	72.6
Net Impairment Losses Recognized in Earnings	(3.4)	(3.2)	(6.3)	(4.1)
Income from Continuing Operations before Income Taxes	102.0	81.5	233.0	128.4
Segment Net Operating Income (Loss)	38.9	24.6	112.9	57.2
Income from Continuing Operations	68.6	55.6	159.7	93.5
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	585.4	594.3	1,757.9	1,799.1
Segment Operating Profit (Loss)	67.4	44.6	196.3	102.7
Segment Net Operating Income (Loss)	46.3	31.8	135.9	76.3
Kemper Preferred [Member]
Segment Reporting Information [Line Items]
Earned Premiums	220.5	222.9	661.2	655.9
Net Investment Income	13.2	10.8	41.4	33.6
Other Income	0.1	0.1	0.2	0.3
Total Revenues	233.8	233.8	702.8	689.8
Segment Operating Profit (Loss)	14.9	10.4	55.0	4.4
Segment Net Operating Income (Loss)	11.2	8.4	40.5	8.5
Kemper Specialty [Member]
Segment Reporting Information [Line Items]
Earned Premiums	98.1	103.9	297.9	317.3
Net Investment Income	5.0	4.5	16.4	14.4
Other Income	0	0.1	0.2	0.2
Total Revenues	103.1	108.5	314.5	331.9
Segment Operating Profit (Loss)	7.2	3.2	11.7	2.5
Segment Net Operating Income (Loss)	5.3	2.7	9.5	4.0
Kemper Direct [Member]
Segment Reporting Information [Line Items]
Earned Premiums	30.1	40.3	95.6	131.2
Net Investment Income	3.1	3.4	10.1	10.7
Total Revenues	33.2	43.7	105.7	141.9
Segment Operating Profit (Loss)	10.1	1.6	31.3	(6.9)
Segment Net Operating Income (Loss)	6.9	1.5	21.5	(2.7)
Life and Health Insurance [Member]
Segment Reporting Information [Line Items]
Earned Premiums	158.8	160.2	475.5	481.9
Net Investment Income	56.5	48.1	159.3	153.5
Other Income	0	0	0.1	0.1
Total Revenues	215.3	208.3	634.9	635.5
Segment Operating Profit (Loss)	35.2	29.4	98.3	102.7
Segment Net Operating Income (Loss)	22.9	19.2	64.4	66.5
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Other Income	4.6	3.6	10.6	10.8
Segment Operating Profit (Loss)	(11.1)	(10.8)	(35.3)	(30.1)
Segment Net Operating Income (Loss)	(7.4)	(7.2)	(23.0)	(19.1)
Net Realized Gains (Losses) on Sales of Investments, Net of Tax	31.9	33.0	50.9	38.9
Net Impairment Losses Recognized in Earnings, Net of Tax	$ (2.2)	$ (2.0)	$ (4.1)	$ (2.6)