Acquisitions (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Apr. 01, 2016
Business Acquisition, Date of Acquisition [Abstract]
Integration costs	$ 25
Capital Expenditures Integration Activities	34
CTF Acquisition [Member]
Business Acquisition, Date of Acquisition [Abstract]
Acquisition purchase price		$ 10,540
Capital Expenditures Integration Activities	$ 34