Catatrophe Reinsurance - Catastrophe Losses and LAE (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Liability for Catastrophe Claims [Line Items]
Catastrophe Loss and LAE Reserves, (Unfavorable) Favorable Developement	$ (31.5)	$ (33.1)	$ (24.9)
Catastrophe Losses and LAE	1,221.6	1,305.4	1,285.6
Catastrophe [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Loss and LAE Reserves, (Unfavorable) Favorable Developement	(6.3)	(6.4)	(1.2)
Catastrophe Losses and LAE	118.2	157.4	78.1
Catastrophe [Member] | Superstorm Sandy [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Losses and LAE	48.5
Catastrophe [Member] | Hurricane Irene [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Losses and LAE		23.0
Kemper Preferred [Member] | Hail [Member]
Liability for Catastrophe Claims [Line Items]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense, Amount			12.9
Kemper Preferred [Member] | Catastrophe [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Loss and LAE Reserves, (Unfavorable) Favorable Developement	(6.2)	(5.5)	(4.9)
Catastrophe Losses and LAE	99.2	138.7	65.2
Kemper Preferred [Member] | Catastrophe [Member] | Superstorm Sandy [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Losses and LAE	44.0
Kemper Preferred [Member] | Catastrophe [Member] | Hurricane Irene [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Losses and LAE		22.1
Kemper Specialty [Member] | Catastrophe [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Losses and LAE	4.9	3.9	3.0
Kemper Direct [Member] | Catastrophe [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Losses and LAE	8.0	7.2	2.0
Life and Health Insurance [Member] | Catastrophe [Member]
Liability for Catastrophe Claims [Line Items]
Catastrophe Loss and LAE Reserves, (Unfavorable) Favorable Developement	0.1	(1.5)	3.4
Catastrophe Losses and LAE	$ 6.1	$ 7.6	$ 7.9