Employee Benefits - Schedule of Fair Value of Other Plan Assets (Details) - Other - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	$ 1,076	$ 1,019	$ 1,161
Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	11	11
Global
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	322	270
Pooled funds - North America
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	36	37
Pooled funds - Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	20	21
Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	166	30
Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	37	48
Pooled funds - Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	469	576
Pooled Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total		12
Alternative investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	9	9
Commodity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total		2
Pooled funds - REITS
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	6	3
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	11	11
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	11	11
Quoted Prices in Active Markets for Identical Assets (Level 1) | Global
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pooled funds - North America
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pooled funds - Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pooled funds - Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pooled Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total		0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Alternative investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commodity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total		0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pooled funds - REITS
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	203	78
Significant Other Observable Inputs (Level 2) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Other Observable Inputs (Level 2) | Global
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Other Observable Inputs (Level 2) | Pooled funds - North America
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Other Observable Inputs (Level 2) | Pooled funds - Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Other Observable Inputs (Level 2) | Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	166	30
Significant Other Observable Inputs (Level 2) | Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	37	48
Significant Other Observable Inputs (Level 2) | Pooled funds - Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Other Observable Inputs (Level 2) | Pooled Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total		0
Significant Other Observable Inputs (Level 2) | Alternative investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Other Observable Inputs (Level 2) | Commodity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total		0
Significant Other Observable Inputs (Level 2) | Pooled funds - REITS
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Global
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Pooled funds - North America
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Pooled funds - Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Pooled funds - Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Pooled Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total		0
Significant Unobservable Inputs (Level 3) | Alternative investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	0	0
Significant Unobservable Inputs (Level 3) | Commodity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total		0
Significant Unobservable Inputs (Level 3) | Pooled funds - REITS
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	$ 0	$ 0