Derivative Financial Instruments and Off-balance sheet Financial Instruments (Details 4) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	$ 11	$ (18)	$ (2)
Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	(24)	(36)
Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	9	(7)	15
Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	18	22	22
Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(16)	(9)	1
Loss on disposition of operations
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	(4)
Interest rate contracts
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives		1	(14)
Interest rate contracts | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives		1	(10)
Interest rate contracts | Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives		0	0
Interest rate contracts | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives		0	0
Interest rate contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives		0	0
Interest rate contracts | Loss on disposition of operations
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives		0	(4)
Equity and index contracts
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	25	(9)	29
Equity and index contracts | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(12)	1	(18)
Equity and index contracts | Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Equity and index contracts | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	18	(9)	38
Equity and index contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	19	(1)	9
Equity and index contracts | Loss on disposition of operations
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Embedded derivative financial instruments
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	9	24	1
Embedded derivative financial instruments | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Embedded derivative financial instruments | Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	9	(7)	15
Embedded derivative financial instruments | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	31	(14)
Embedded derivative financial instruments | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Embedded derivative financial instruments | Loss on disposition of operations
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Foreign currency contracts
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(18)	(32)	(17)
Foreign currency contracts | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	17	(24)	(9)
Foreign currency contracts | Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Foreign currency contracts | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Foreign currency contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(35)	(8)	(8)
Foreign currency contracts | Loss on disposition of operations
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Credit default swaps
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(5)	(2)	1
Credit default swaps | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	(5)	(2)	1
Credit default swaps | Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Credit default swaps | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Credit default swaps | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	0	0	0
Credit default swaps | Loss on disposition of operations
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives	$ 0	$ 0	0
Other contracts
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives			(2)
Other contracts | Realized capital gains and losses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives			0
Other contracts | Life and annuity contract benefits
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives			0
Other contracts | Interest credited to contractholder funds
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives			(2)
Other contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives			0
Other contracts | Loss on disposition of operations
Derivative Instruments, Gain (Loss)
Derivatives not designated as accounting hedging instruments, total gain (loss) recognized in net income on derivatives			$ 0