Commitments And Contingencies Operating Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Rent Expense	$ 96	$ 95	$ 105
Operating Leases, Minimum Lease Commitments	$ 358