Income Taxes Level 4 Capital Loss Carryover (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 91	$ 0
Deferred Tax Assets, Capital Loss Carryforwards	$ 32	$ 0
Tax Year 2022 [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2022