Business Segments - Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 segments	Mar. 31, 2011
Segment Reporting Information [Line Items]
Number of Operating Segments	4
Earned Premiums	$ 529.2	$ 546.0
Net Investment Income	77.4	81.2
Other Income	0.2	0.2
Total Revenues	611.2	641.2
Net Realized Gains on Sales of Investments	4.9	14.2
Net Impairment Losses Recognized in Earnings	(0.5)	(0.4)
Segment Operating Profit (Loss)	46.0	49.3
Income from Continuing Operations before Income Taxes	50.4	63.1
Segment Net Operating Income (Loss)	33.4	36.1
Income from Continuing Operations	36.3	45.0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	604.8	625.0
Segment Operating Profit (Loss)	58.0	58.5
Segment Net Operating Income (Loss)	41.0	41.8
Kemper Preferred [Member]
Segment Reporting Information [Line Items]
Earned Premiums	215.0	211.9
Net Investment Income	10.9	14.2
Other Income	0.1	0.1
Total Revenues	226.0	226.2
Segment Operating Profit (Loss)	13.1	14.1
Segment Net Operating Income (Loss)	10.4	11.3
Kemper Specialty [Member]
Segment Reporting Information [Line Items]
Earned Premiums	106.8	112.4
Net Investment Income	5.2	6.6
Other Income	0	0.1
Total Revenues	112.0	119.1
Segment Operating Profit (Loss)	4.9	5.4
Segment Net Operating Income (Loss)	4.1	4.4
Kemper Direct [Member]
Segment Reporting Information [Line Items]
Earned Premiums	47.0	59.9
Net Investment Income	3.6	5.3
Total Revenues	50.6	65.2
Segment Operating Profit (Loss)	(3.0)	(7.5)
Segment Net Operating Income (Loss)	(1.3)	(3.9)
Life and Health Insurance [Member]
Segment Reporting Information [Line Items]
Earned Premiums	160.4	161.8
Net Investment Income	55.7	52.7
Other Income	0.1	0
Total Revenues	216.2	214.5
Segment Operating Profit (Loss)	43.0	46.5
Segment Net Operating Income (Loss)	27.8	30.0
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Other Income	2.0	2.4
Segment Operating Profit (Loss)	(12.0)	(9.2)
Segment Net Operating Income (Loss)	(7.6)	(5.7)
Net Realized Gains on Sales of Investments, Net of Tax	3.2	9.2
Net Impairment Losses Recognized in Earnings, Net of Tax	$ 0.3	$ 0.3