Business Segments - Capital Expenditures Depreciation and Amortization (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Capital expenditures	$ 996	$ 983	$ 923
Depreciation and amortization	727	698	732
Operating Segments
Segment Reporting Information [Line Items]
Capital expenditures	946	965	854
Depreciation and amortization	678	664	701
Operating Segments | Americas
Segment Reporting Information [Line Items]
Capital expenditures	618	618	434
Depreciation and amortization	366	364	376
Operating Segments | Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Capital expenditures	191	223	266
Depreciation and amortization	192	186	220
Operating Segments | Asia Pacific
Segment Reporting Information [Line Items]
Capital expenditures	137	124	154
Depreciation and amortization	120	114	105
Corporate
Segment Reporting Information [Line Items]
Capital expenditures	50	18	69
Depreciation and amortization	$ 49	$ 34	$ 31