Postretirement Benefit Plans - Plan Assets by Level Three Hierarchy (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 1,034	$ 1,019	$ 1,082
U.S. defined benefit plan | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	1,034	770
U.S. defined benefit plan | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		685	664
U.S. defined benefit plan | Fixed income securities and cash equivalents | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	685	415
U.S. defined benefit plan | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		349	355
U.S. defined benefit plan | Equity securities | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	349	355
U.S. defined benefit plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. defined benefit plan | Level 1 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. defined benefit plan | Level 1 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. defined benefit plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	249
U.S. defined benefit plan | Level 2 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	249
U.S. defined benefit plan | Level 2 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. defined benefit plan | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. defined benefit plan | Level 3 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. defined benefit plan | Level 3 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. retiree health care plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		434	441	497
U.S. retiree health care plan | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	251	258
U.S. retiree health care plan | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		227	220
U.S. retiree health care plan | Fixed income securities and cash equivalents | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	44	37
U.S. retiree health care plan | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		207	221
U.S. retiree health care plan | Equity securities | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	207	221
U.S. retiree health care plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		180	178
U.S. retiree health care plan | Level 1 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		180	178
U.S. retiree health care plan | Level 1 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. retiree health care plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3	5
U.S. retiree health care plan | Level 2 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3	5
U.S. retiree health care plan | Level 2 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. retiree health care plan | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. retiree health care plan | Level 3 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
U.S. retiree health care plan | Level 3 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
Non-U.S. defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2,309	2,134	$ 2,213
Non-U.S. defined benefit plan | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	2,137	1,993
Non-U.S. defined benefit plan | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,654	1,498
Non-U.S. defined benefit plan | Fixed income securities and cash equivalents | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	1,508	1,385
Non-U.S. defined benefit plan | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		652	632
Non-U.S. defined benefit plan | Equity securities | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	629	608
Non-U.S. defined benefit plan | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3	4
Non-U.S. defined benefit plan | Other | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	0	0
Non-U.S. defined benefit plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		24	10
Non-U.S. defined benefit plan | Level 1 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		19	4
Non-U.S. defined benefit plan | Level 1 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		5	6
Non-U.S. defined benefit plan | Level 1 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
Non-U.S. defined benefit plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		145	127
Non-U.S. defined benefit plan | Level 2 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		127	109
Non-U.S. defined benefit plan | Level 2 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		18	18
Non-U.S. defined benefit plan | Level 2 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
Non-U.S. defined benefit plan | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3	4
Non-U.S. defined benefit plan | Level 3 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
Non-U.S. defined benefit plan | Level 3 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
Non-U.S. defined benefit plan | Level 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 3	$ 4

[1] Consists of bond index and equity index funds, measured at net asset value per share.