Income Taxes Level 4 Capital Loss Carryover (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Valuation Allowance					$ 1
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	$ 53	$ (4)	$ 78	$ (3)
Capital Loss Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Valuation Allowance	$ 0		$ 0