Fair Value of Assets and Liabilities (Details 5) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	$ 0	$ 3	$ (15)	$ 5
Total recurring Level 3 liabilities	7	9	(8)	5
Fair value, assets and liabilities gain (loss) included in earnings	7	13	(9)	7
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	(4)		(22)	(1)
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	4	3	7	6
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	(7)	9	(6)	5
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	14		(2)
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	7	12	(23)	10
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	7	9	(8)	5
Corporate
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	3	3	1	5
CMBS
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	0	(1)	0	(1)
Free-standing derivatives, net
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	1	1	0	1
Fixed income securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	3	2	1	4
Equity securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Total recurring Level 3 assets	$ (4)	$ 0	$ (16)	$ 0