Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Tax valuation allowance, continuing operations	Dec. 31, 2011 Tax valuation allowance, continuing operations	Sep. 30, 2012 Tax valuation allowance, realized and unrealized capital losses	Dec. 31, 2011 Tax valuation allowance, realized and unrealized capital losses	Sep. 30, 2012 Tax valuation allowance, excess deferred tax assets over deferred tax liabilities	Jun. 30, 2012 Tax valuation allowance, foreign tax credits	Dec. 31, 2011 Tax valuation allowance, foreign tax credits
Valuation Allowance [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	$ 237.8	$ 22.3	$ (78.0)	$ 141.9
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Statutory rate	35.00%	35.00%	35.00%	35.00%
Income Tax Reconciliation, Income Tax Expense (Benefit), at Federal Statutory Income Tax Rate	83.2	7.8	(27.3)	49.7
Income Tax Reconciliation, Deductions, Dividends	(36.2)	9.6	(58.3)	(19.3)
Income Tax Reconciliation, Change in Deferred Tax Assets Valuation Allowance	(1.0)	(117.0)	59.5	(127.0)
Income Tax Reconciliation, Tax Settlements, Other			0	3.3
Income Tax Reconciliation, Tax Credits	(0.5)	(0.5)	(1.5)	(1.5)
Income Tax Reconciliation, Other Adjustments	0.1	0.1	0.2	0.3
Income Tax Expense (Benefit), Continuing Operations	45.6	(100.0)	(27.4)	(94.5)
Valuation allowance, deferred tax assets					$ 217.6	$ 158.1	$ (25.5)	$ (146.0)	$ 180.0	$ 12.1	$ 12.1