Restructuring, Impairment and Other - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Restructuring, impairment and other	$ 71	$ 66	$ 183	$ 374
Restructuring charges	38	49	145	242
Estimated remaining charges	32		32
Corporate
Restructuring and Related Activities [Abstract]
Restructuring charges	0	2	12	23
Restructuring, impairment and other charges
Restructuring Cost and Reserve [Line Items]
Other asset impairment charges and gain (loss), realized	$ 33	$ 17	$ 38	132
Restructuring, impairment and other charges | Corporate
Restructuring Cost and Reserve [Line Items]
Other asset impairment charges and gain (loss), realized				25
Restructuring, impairment and other charges | Operating segments | TPS and OFS Segment
Restructuring Cost and Reserve [Line Items]
Other asset impairment charges and gain (loss), realized				$ 12