Postretirement Benefit Plans - Plan Assets by Level Three Heirarchy (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
U.S. defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,019	$ 1,082	$ 941
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 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,019	1,082
U.S. defined benefit plan | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0	37
U.S. defined benefit plan | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	664	707
U.S. defined benefit plan | Fixed income securities and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. defined benefit plan | Fixed income securities and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	664	707
U.S. defined benefit plan | Fixed income securities and cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. defined benefit plan | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	355	375
U.S. defined benefit plan | Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. defined benefit plan | Equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	355	375
U.S. defined benefit plan | Equity securities | Level 3
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	441	497	485
U.S. retiree health care plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	178	200
U.S. retiree health care plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	263	297
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 | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	220	243
U.S. retiree health care plan | Fixed income securities and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	178	200
U.S. retiree health care plan | Fixed income securities and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	42	43
U.S. retiree health care plan | Fixed income securities and cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. retiree health care plan | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	221	254
U.S. retiree health care plan | Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. retiree health care plan | Equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	221	254
U.S. retiree health care plan | Equity securities | Level 3
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	2,134	2,213	2,179
Non-U.S. defined benefit plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	446	436
Non-U.S. defined benefit plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,684	1,772
Non-U.S. defined benefit plan | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	5	$ 8
Non-U.S. defined benefit plan | Fixed income securities and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,498	1,608
Non-U.S. defined benefit plan | Fixed income securities and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	440	430
Non-U.S. defined benefit plan | Fixed income securities and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,058	1,178
Non-U.S. defined benefit plan | Fixed income securities and cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Non-U.S. defined benefit plan | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	632	600
Non-U.S. defined benefit plan | Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	6
Non-U.S. defined benefit plan | Equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	626	594
Non-U.S. defined benefit plan | Equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Non-U.S. defined benefit plan | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	5
Non-U.S. defined benefit plan | Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Non-U.S. defined benefit plan | Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Non-U.S. defined benefit plan | Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 4	$ 5