Derivatives (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Summary of gain (loss) included in earnings for changes in the fair value of derivatives
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 2	$ 2
MBS with embedded derivatives [Member] | Realized gains [Member]
Summary of gain (loss) included in earnings for changes in the fair value of derivatives
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	2	4
Public company warrants [Member] | Realized gains [Member]
Summary of gain (loss) included in earnings for changes in the fair value of derivatives
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	2	0
Interest rate swaptions [Member] | Realized gains [Member]
Summary of gain (loss) included in earnings for changes in the fair value of derivatives
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0	0
Fixed-indexed annuities (embedded derivative) [Member] | Annuity benefits [Member]
Summary of gain (loss) included in earnings for changes in the fair value of derivatives
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(80)	(60)
Equity index call options [Member] | Annuity benefits [Member]
Summary of gain (loss) included in earnings for changes in the fair value of derivatives
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	77	57
Reinsurance contracts (embedded derivative) [Member] | Investment Income [Member]
Summary of gain (loss) included in earnings for changes in the fair value of derivatives
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 1	$ 1