Investments (Details 8) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Net Unrealized Gains and Losses on Available-for-Sale Securities and Derivative Instruments
Net unrealized gains (losses) on fixed maturities, available-for-sale	$ 1,891.1	$ 1,197.7
Noncredit component of impairment losses on fixed maturities, available-for-sale	(251.0)	(334.5)
Net unrealized gains (losses) on equity securities, available-for-sale	(0.4)	(10.1)
Adjustments for assumed changes in amortization patterns	(445.7)	(273.8)
Adjustments for assumed changes in policyholder liabilities	(245.8)	(212.4)
Net unrealized gains (losses) on derivative instruments	107.2	53.5
Net unrealized gains (losses) on equity method subsidiaries and noncontrolling interest adjustments	151.4	145.2
Provision for deferred income tax benefits (taxes)	(395.2)	(169.0)
Effect of implementation of accounting change related to variable interest entities, net		10.7
Effect of electing fair value option for fixed maturities upon implementation of accounting change related to embedded credit derivatives, net		25.4
Net unrealized gains (losses) on available-for-sale securities and derivative instruments	$ 811.6	$ 432.7

Accumulated other comprehensive income or loss related to other-than-temporary impairment not a credit loss for available-for-sale debt securities.

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This item represents the cumulative net unrealized gains/losses adjustment related to deferred policy acquisition costs, sales inducements and unearned revenue reserves.

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This item represents the cumulative net unrealized gains/losses adjustment related to changes in policyholder benefits and claims and changes in the policyholder dividend obligation.

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This item represents the balance sheet side of the after-tax impact resulting from the adoption of new embedded credit derivative accounting guidance and represents the unrealized losses, net of assumed changes in amortization patterns, on fixed maturities for which the fair value option was elected, effectively reclassifying them from available-for-sale to trading.

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This item represents the balance sheet side of the after-tax impact resulting from the adoption of new variable interest entities accounting guidance and consists of (a) the difference between the net amount added to the consolidated balance sheet and the amount of any previously recognized interest in newly consolidated variable interest entities and (b) the difference between the net amount removed from the consolidated balance sheet and the amount of any retained interest in newly deconsolidated variable interest entities.

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The cumulative net unrealized gains/losses on fixed maturities available-for-sale, equity securities available-for-sale and derivative instruments net of adjustments related to deferred policy acquisition costs, sales inducements, unearned revenue reserves, changes in policyholder benefits and claims and applicable income taxes.

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This item represents the cumulative net unrealized gains and losses on fixed maturities available-for-sale, excluding hedged portions of those in fair value hedging.

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This item represents the cumulative net unrealized gains/losses on derivatives in qualifying cash flow hedges.

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This item represents the cumulative net unrealized gains/losses on investments in our subsidiaries, which represents the difference between the market value and original cost of the investment in the subsidiary.

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This item represents the cumulative net unrealized gains/losses for equity securities available-for-sale.

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This item represents the applicable deferred income tax impacts of cumulative net unrealized gains/losses on fixed maturities available-for-sale, equity securities available-for-sale and derivative instruments net of adjustments related deferred policy acquisition costs, sales inducements, unearned revenue reserves, and changes in policyholder benefits and claims.

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