Income Tax Level 4 Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Period Increase (Decrease)	$ 36
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	125	$ 186	$ 301
Effective Income Tax Rate Reconciliation, Deduction, Dividends, Amount	76	152	109
Income Tax Reconciliation, Deductions, Foreign Investments	7	3	8
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	1	(1)	0
Income Tax Expense (Benefit)	74	30	184
Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	$ 31	$ 0	$ 0