Derivatives (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2015	Sep. 30, 2014	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Indexed annuities as a percentage of annuity benefits	50.00%
Carrying value of collateral received to support purchased call options	$ 262,000,000
Not Designated as Hedging Instrument [Member] | Interest rate swaptions [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivative asset instrument outstanding	200,000,000
Payments to purchase swaptions	4,000,000
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Interest rate swaptions [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Contract term of derivative instrument	5 years	5 years
Notional amount of derivative instrument outstanding	374,000,000	431,000,000	401,000,000
Net derivatives, at fair value (are less than in 2014)	(2,000,000)
Gain (loss) reclassified from AOCI into net investment income	1,000,000
Gain (loss) on cash flow hedge ineffectiveness recorded in Net Earnings	0
Maximum [Member] | Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Interest rate swaptions [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives, at fair value (are less than in 2014)			$ (1,000,000)