Fair Value of Assets and Liabilities (Details 5) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	$ 5	$ 1	$ (10)	$ 9
Total recurring Level 3 liabilities	(2)	19	(10)	24
Fair value, assets and liabilities gain (loss) included in earnings	3	30	(6)	37
Realized capital gains and losses
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 assets and liabilities still held at the balance sheet date	3	(2)	(19)	(2)
Net investment income
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 assets and liabilities still held at the balance sheet date	2	3	9	11
Interest credited to contractholder funds
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 assets and liabilities still held at the balance sheet date	(5)	27	(11)	32
Contract benefits
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 assets and liabilities still held at the balance sheet date	3	(8)	1	(8)
Gain (loss) on investments
Gains (losses) included in net income for Level 3 assets and liabilities:
Fair value, assets and liabilities gain (loss) included in earnings	3	20	(20)	33
Contractholder funds: Derivatives embedded in life and annuity contracts
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 liabilities	(2)	19	(10)	24
Municipal
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	1	0	1	0
Corporate
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	0	3	1	8
ABS
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	0	0	0	1
Free-standing derivatives, net
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	4	(1)	4	0
Fixed income securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	1	3	2	9
Equity securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	$ 0	$ (1)	$ (16)	$ 0