Income From Continuing Operations Per Unrestricted Share (Details) (USD $) In Millions, except Share data, 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
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income from Continuing Operations	$ (1.7)	$ 55.6	$ 1.6	$ 36.3	$ 25.0	$ 1.1	$ (9.4)	$ 45.0	$ 91.8	$ 61.7	$ 162.4
Dilutive Effect on Income of Kemper Equity-based Compensation Equivalent Shares									0	0	0
Diluted Income from Continuing Operations Attributed to Unrestricted Shares									91.3	61.4	161.6
Weighted-Average Unrestricted Shares Outstanding									58,857,300	60,262,600	61,681,200
Kemper Equity-based Compensation Equivalent Shares									141,700	103,900	85,700
Weighted-Average Unrestricted Shares and Equivalent Shares Outstanding Assuming Dilution									58,999,000	60,366,500	61,766,900
Basic Income from Continuing Operations Per Unrestricted Share	$ (0.03)	$ 0.95	$ 0.03	$ 0.61	$ 0.41	$ 0.01	$ (0.16)	$ 0.74	$ 1.55	$ 1.02	$ 2.62
Diluted Income from Continuing Operations Per Unrestricted Share	$ (0.03)	$ 0.95	$ 0.03	$ 0.60	$ 0.41	$ 0.01	$ (0.16)	$ 0.73	$ 1.54	$ 1.02	$ 2.62
Restricted Stock [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income from Continuing Operations									0.5	0.3	0.8
Common Stock [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income from Continuing Operations									$ 91.3	$ 61.4	$ 161.6