Business Segments - Segment Operating Profit (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Operating Income (Loss)									$ 63.9	$ 45.9	$ 200.2
Net Realized Gains on Sales of Investments	5.5	50.9	4.1	4.9	5.9	(4.2)	17.8	14.2	65.4	33.7	42.6
Net Impairment Losses Recognized in Earnings	(2.8)	(3.2)	(0.4)	(0.5)	(4.6)	(5.0)	(1.3)	(0.4)	(6.9)	(11.3)	(16.5)
Income from Continuing Operations before Income Taxes and Equity in Net Loss of Former Investee	(6.0)	81.5	(3.5)	50.4	31.1	(5.0)	(20.9)	63.1	122.4	68.3	226.3
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)									104.8	88.7	226.5
Kemper Preferred [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)									(28.0)	(40.6)	66.9
Kemper Specialty [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)									(2.8)	24.2	25.6
Kemper Direct [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)									(4.8)	(47.2)	(7.9)
Life and Health Insurance [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)									140.4	152.3	141.9
Unallocated Amount to Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)									$ (40.9)	$ (42.8)	$ (26.3)