Funding Sources Network LeaseCo (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 30, 2016	Mar. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Sale Leaseback Transaction, Net Book Value		$ 1,200	$ 500	$ 1,300
Sale Leaseback Transaction, Net Proceeds, Financing Activities		$ 600
Network Sale-Leaseback [Member]
Sale Leaseback Transaction, Net Book Value			3,000
Sale Leaseback Transaction, Net Proceeds, Financing Activities	$ 2,200
Sale Leaseback Transaction, Annual Rental Payments			$ 300