Business Segments - Segment Assets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Assets	$ 8,009.1	$ 7,934.7
Kemper Preferred [Member]
Segment Reporting Information [Line Items]
Assets	1,562.0	1,544.0
Kemper Specialty [Member]
Segment Reporting Information [Line Items]
Assets	684.6	615.8
Kemper Direct [Member]
Segment Reporting Information [Line Items]
Assets	453.3	570.8
Life and Health Insurance [Member]
Segment Reporting Information [Line Items]
Assets	4,781.8	4,802.5
Corporate and Other, Net [Member]
Segment Reporting Information [Line Items]
Assets	$ 527.4	$ 401.6