Restructuring Expenses (Details) (USD $) In Millions	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	$ 6.4	$ 5.2
Restructuring Liability, Expenses Incurred	4.9	2.5
Restructuring Liability, Payments	1.8	2.4
Restructuring Liability, Ending Balance	9.5	5.3
Restructuring Costs Expected to Be Recognized Within the Fiscal Year [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring and Related Cost, Expected Cost	1.8
Restructuring Costs Expected to Be Recognized Beyond the Current Fiscal Year [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring and Related Cost, Expected Cost	3.4
Fireside Bank [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	5.7	3.0
Restructuring Liability, Expenses Incurred	2.8	1.8
Restructuring Liability, Payments	0.6	0.6
Restructuring Liability, Ending Balance	7.9	4.2
Fireside Bank [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	5.7	2.8
Restructuring Liability, Expenses Incurred	2.8	1.7
Restructuring Liability, Payments	0.6	0.3
Restructuring Liability, Ending Balance	7.9	4.2
Fireside Bank [Member] | Contract Termination [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	0	0.2
Restructuring Liability, Expenses Incurred	0	0
Restructuring Liability, Payments	0	0.2
Restructuring Liability, Ending Balance	0	0
Fireside Bank [Member] | Other Associated Costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance		0
Restructuring Liability, Expenses Incurred		0.1
Restructuring Liability, Payments		0.1
Restructuring Liability, Ending Balance		0
Unitrin Direct [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	0.7	2.0
Restructuring Liability, Expenses Incurred	1.7	0.5
Restructuring Liability, Payments	0.8	1.4
Restructuring Liability, Ending Balance	1.6	1.1
Unitrin Direct [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	0.6	1.4
Restructuring Liability, Expenses Incurred	0.4	0.5
Restructuring Liability, Payments	0.7	1.2
Restructuring Liability, Ending Balance	0.3	0.7
Unitrin Direct [Member] | Contract Termination [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	0.1	0.6
Restructuring Liability, Expenses Incurred	1.3	0
Restructuring Liability, Payments	0.1	0.2
Restructuring Liability, Ending Balance	1.3	0.4
Unitrin Direct [Member] | Other Associated Costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance		0
Restructuring Liability, Expenses Incurred		0
Restructuring Liability, Payments		0
Restructuring Liability, Ending Balance		0
All Other Segments [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	0	0.2
Restructuring Liability, Expenses Incurred	0.4	0.2
Restructuring Liability, Payments	0.4	0.4
Restructuring Liability, Ending Balance	0	0
All Other Segments [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	0	0.2
Restructuring Liability, Expenses Incurred	0.4	0.2
Restructuring Liability, Payments	0.4	0.4
Restructuring Liability, Ending Balance	0	0
All Other Segments [Member] | Contract Termination [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	0	0
Restructuring Liability, Expenses Incurred	0	0
Restructuring Liability, Payments	0	0
Restructuring Liability, Ending Balance	0	0
All Other Segments [Member] | Other Associated Costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance		0
Restructuring Liability, Expenses Incurred		0
Restructuring Liability, Payments		0
Restructuring Liability, Ending Balance		0
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	6.3	4.4
Restructuring Liability, Expenses Incurred	3.6	2.4
Restructuring Liability, Payments	1.7	1.9
Restructuring Liability, Ending Balance	8.2	4.9
Restructuring and Related Cost, Expected Cost	5.2
Contract Termination [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance	0.1	0.8
Restructuring Liability, Expenses Incurred	1.3	0
Restructuring Liability, Payments	0.1	0.4
Restructuring Liability, Ending Balance	1.3	0.4
Other Associated Costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Liability, Beginning Balance		0
Restructuring Liability, Expenses Incurred		0.1
Restructuring Liability, Payments		0.1
Restructuring Liability, Ending Balance		$ 0