Goodwill and Other Purchased Intangible Assets Goodwill and Other Purchased Intangible Assets (Details 4) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Amortization of Intangible Assets	$ 203	$ 14	$ 16
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	12 years
Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill, Impaired, Accumulated Impairment Loss	$ 570	$ 570