Benefit Plans (Fair Value of Plan Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		$ 1,044	$ 1,021	$ 1,061
U.S. Defined Benefit Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		1,011	968
U.S. Defined Benefit Plans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		33	53
U.S. Defined Benefit Plans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		532	457
U.S. Defined Benefit Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		532	457
U.S. Defined Benefit Plans | Mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Mutual funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Government debt securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		86	53
U.S. Defined Benefit Plans | Government debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		86	53
U.S. Defined Benefit Plans | Government debt securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Government debt securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[1]	393	458
U.S. Defined Benefit Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[1]	393	458
U.S. Defined Benefit Plans | Mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[1]	0	0
U.S. Defined Benefit Plans | Mutual funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[1]	0	0
U.S. Defined Benefit Plans | Real estate
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		33	30
U.S. Defined Benefit Plans | Real estate | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Real estate | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		33	30
U.S. Defined Benefit Plans | Real estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Other investments
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	23
U.S. Defined Benefit Plans | Other investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Other investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	23
U.S. Defined Benefit Plans | Other investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		2,824	2,195	3,144
Foreign Defined Benefit Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		424	400
Foreign Defined Benefit Plans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		2,116	1,559
Foreign Defined Benefit Plans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		284	236	$ 389
Foreign Defined Benefit Plans | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		175	156
Foreign Defined Benefit Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		175	156
Foreign Defined Benefit Plans | Mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Mutual funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Private equity
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	150	124
Foreign Defined Benefit Plans | Private equity | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	0	0
Foreign Defined Benefit Plans | Private equity | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	0	0
Foreign Defined Benefit Plans | Private equity | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	150	124
Foreign Defined Benefit Plans | Corporate debt securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		67	0
Foreign Defined Benefit Plans | Corporate debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Corporate debt securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		67	0
Foreign Defined Benefit Plans | Corporate debt securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Government debt securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		10	40
Foreign Defined Benefit Plans | Government debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		10	11
Foreign Defined Benefit Plans | Government debt securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	29
Foreign Defined Benefit Plans | Government debt securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[3]	2,264	1,747
Foreign Defined Benefit Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[3]	215	217
Foreign Defined Benefit Plans | Mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[3]	2,049	1,530
Foreign Defined Benefit Plans | Mutual funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[3]	0	0
Foreign Defined Benefit Plans | Real estate
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	89	73
Foreign Defined Benefit Plans | Real estate | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	0	0
Foreign Defined Benefit Plans | Real estate | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	0	0
Foreign Defined Benefit Plans | Real estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	89	73
Foreign Defined Benefit Plans | Participant loans
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[4]	42	37
Foreign Defined Benefit Plans | Participant loans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[4]	0	0
Foreign Defined Benefit Plans | Participant loans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[4]	0	0
Foreign Defined Benefit Plans | Participant loans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[4]	42	37
Foreign Defined Benefit Plans | Other assets
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		27	18
Foreign Defined Benefit Plans | Other assets | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		24	16
Foreign Defined Benefit Plans | Other assets | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Other assets | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		$ 3	$ 2

[1] Mutual funds categorized as debt securities consist of mutual funds for which debt securities are the primary underlying investment

[2] Plan assets of our Brazilian subsidiaries are invested in private equities and commercial real estate through the plan administrator in Brazil. The fair value of these assets is determined using the income approach through annual appraisals based on a discounted cash flow analysis

[3] Mutual funds categorized as debt securities consist of mutual funds for which debt securities are the primary underlying investment

[4] Loans to participants are stated at cost, which approximates fair value