Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Goodwill, Impairment Loss			$ 6,500		$ 6,500
Goodwill, Gross	$ 8,100		8,100		$ 8,100
Amortization of Intangible Assets	18	$ 15	35	$ 29
Finite-Lived Intangible Assets, Amortization Expense, Remainder of 2017	69		69
Finite-Lived Intangible Assets, Amortization Expense, 2018	69		69
Finite-Lived Intangible Assets, Amortization Expense, 2019	69		69
Finite-Lived Intangible Assets, Amortization Expense, 2020	65		65
Finite-Lived Intangible Assets, Amortization Expense, 2021	65		65
Finite-Lived Intangible Assets, Amortization Expense, 2022	$ 65		65
Optical Communications [Member]
Finite-lived Intangible Assets Acquired			71
Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss)			10
Amortization of Intangible Assets			$ 35