Fair Value of Assets and Liabilities (Details 4) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	$ 10	$ (27)
Gains (losses) for Level 3 liabilities still held at the balance sheet date, included in earnings	3	(15)
Total realized and unrealized gains (losses) included in net income, recurring Level 3 assets and liabilities	14	(29)
Gain (Loss) on Investments
Gains (losses) included in net income for Level 3 assets and liabilities:
Total realized and unrealized gains (losses) included in net income, recurring Level 3 assets and liabilities	13	(42)
Realized capital gains and losses
Gains (losses) included in net income for Level 3 assets and liabilities:
Change in unrealized gain (loss)	1	(29)
Net investment income
Gains (losses) included in net income for Level 3 assets and liabilities:
Change in unrealized gain (loss)	10	2
Interest credited to contractholder funds
Gains (losses) included in net income for Level 3 assets and liabilities:
Change in unrealized gain (loss)	(5)	1
Life and annuity contract benefits
Gains (losses) included in net income for Level 3 assets and liabilities:
Change in unrealized gain (loss)	7	(16)
Derivatives embedded in life and annuity contracts
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 liabilities still held at the balance sheet date, included in earnings	3	(15)
Corporate
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	0	(2)
Equity securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	10	(24)
Free-standing derivatives, net
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	1	(1)
Other assets
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	$ (1)	$ 0