Restructuring Charges (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Charges (Textuals) [Abstract]
Restructuring charges, net of revisions	$ 42	$ 329	$ (26)
Restructuring Charges	722
Corporate and Other [Member]
Restructuring Charges (Textuals) [Abstract]
Restructuring charges, net of revisions	61
Restructuring Charges	403
Downsizing and Reorganizing Operations [Member]
Restructuring Charges (Textuals) [Abstract]
Restructuring charges, net of revisions	0	81	61
Employee Severance [Member]
Restructuring Charges (Textuals) [Abstract]
Restructuring charges, net of revisions	34	$ 305	$ (33)
Employee Severance [Member] | Corporate and Other [Member]
Restructuring Charges (Textuals) [Abstract]
Restructuring Charges	$ 336