Income Taxes Level 4 Net Operating Loss Carryover (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Valuation Allowance	$ 1
Deferred Tax Assets, Operating Loss Carryforwards, Domestic		$ 1,814
Deferred Tax Assets, Operating Loss Carryforwards, Foreign		17
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	$ 138	154
Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2016
Expiring within Tax Years 2016 to 2020 [Domain]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 4
Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2036
Expiring within Tax Years 2023 to 2033 [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 5,016
No expiration tax year [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	80
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	5,020
Deferred Tax Assets, Operating Loss Carryforwards	1,757
Operating Loss Carryforwards		5,182
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	80
Deferred Tax Assets, Operating Loss Carryforwards	16
Operating Loss Carryforwards		89
Before Tax [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Deferred Tax Asset	138	154
Tax Credit Carryforward, Amount	$ 60	$ 222