Goodwill (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended						12 Months Ended			12 Months Ended			3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2010 Kemper Preferred [Member]	Dec. 31, 2012 Kemper Preferred [Member]	Dec. 31, 2011 Kemper Preferred [Member]	Dec. 31, 2010 Kemper Specialty [Member]	Dec. 31, 2012 Kemper Specialty [Member]	Dec. 31, 2011 Kemper Specialty [Member]	Dec. 31, 2010 Life and Health Insurance [Member]	Dec. 31, 2012 Life and Health Insurance [Member]	Dec. 31, 2011 Life and Health Insurance [Member]	Sep. 30, 2010 Reserve National [Member]
Goodwill [Roll Forward]
Goodwill, Balance at Beginning of Year	$ 311.8	$ 311.8	$ 331.8	$ 49.6	$ 49.6	$ 49.6	$ 42.8	$ 42.8	$ 42.8	$ 239.4	$ 219.4	$ 219.4
Write-off of Goodwill	0	0	(14.8)	0			0			(14.8)			(14.8)
Other			(5.2)	0			0			(5.2)
Goodwill, Balance at End of Year	$ 311.8	$ 311.8	$ 311.8	$ 49.6	$ 49.6	$ 49.6	$ 42.8	$ 42.8	$ 42.8	$ 219.4	$ 219.4	$ 219.4