Income Taxes Level 4 Net Operating Loss Carrryover (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Valuation Allowance	$ 1
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	3,289	$ 3,333
Expiring within Tax Years 2016 to 2017 [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 3
Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2023
Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2033