Basis of Presentation (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011 Accounting Standards Update 2010-26 [Member]	Sep. 30, 2011 Accounting Standards Update 2010-26 [Member] As Originally Reported [Member]	Sep. 30, 2011 Accounting Standards Update 2010-26 [Member] As Originally Reported [Member]	Sep. 30, 2012 Accounting Standards Update 2010-26 [Member] Effect of Change [Member]	Sep. 30, 2011 Accounting Standards Update 2010-26 [Member] Effect of Change [Member]	Sep. 30, 2012 Accounting Standards Update 2010-26 [Member] Effect of Change [Member]	Sep. 30, 2011 Accounting Standards Update 2010-26 [Member] Effect of Change [Member]
Accounting Policy Disclosures [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets					$ (99.5)
Income Statement [Abstract]
Insurance Expenses	172.7	176.8	502.8	513.5		172.6	500.8		4.2		12.7
Income Tax Benefit (Expense)	(25.9)	6.1	(34.9)	(0.5)		4.6	(5.1)		1.5		4.6
Income from Continuing Operations	55.6	1.1	93.5	36.7		3.8	44.8	(2.5)	(2.7)	(7.5)	(8.1)
Net Income	$ 55.6	$ 2.0	$ 101.5	$ 50.2		$ 4.7	$ 58.3	$ (2.5)	$ (2.7)	$ (7.5)	$ (8.1)
Income from Continuing Operations Per Unrestricted Share:
Basic (in dollars per share)	$ 0.95	$ 0.01	$ 1.57	$ 0.61		$ 0.06	$ 0.74	$ (0.04)	$ (0.05)	$ (0.13)	$ (0.13)
Diluted (in dollars per share)	$ 0.95	$ 0.01	$ 1.56	$ 0.61		$ 0.06	$ 0.74	$ (0.04)	$ (0.05)	$ (0.13)	$ (0.13)
Net Income Per Unrestricted Share:
Basic (in dollars per share)	$ 0.95	$ 0.03	$ 1.71	$ 0.83		$ 0.08	$ 0.96	$ (0.04)	$ (0.05)	$ (0.13)	$ (0.13)
Diluted (in dollars per share)	$ 0.95	$ 0.03	$ 1.70	$ 0.83		$ 0.08	$ 0.96	$ (0.04)	$ (0.05)	$ (0.13)	$ (0.13)