Benefit Plans (Fair Value of Plan Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
U.S. Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		$ 1,021	$ 1,061	$ 941
U.S. Defined Benefit Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		968	1,011
U.S. Defined Benefit Plans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		53	50
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		457	467
U.S. Defined Benefit Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		457	467
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		53	67
U.S. Defined Benefit Plans | Government debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		53	67
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]	458	473
U.S. Defined Benefit Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[1]	458	473
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		30	26
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		30	26
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 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	4
U.S. Defined Benefit Plans | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	4
U.S. Defined Benefit Plans | Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
U.S. Defined Benefit Plans | Cash and cash equivalents | 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		23	24
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		23	24
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		2,284	3,272	3,605
Foreign Defined Benefit Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		421	523
Foreign Defined Benefit Plans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		1,623	2,353
Foreign Defined Benefit Plans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		240	396	$ 530
Foreign Defined Benefit Plans | Common stock
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		9	21
Foreign Defined Benefit Plans | Common stock | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		9	21
Foreign Defined Benefit Plans | Common stock | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Common stock | 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		167	274
Foreign Defined Benefit Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		167	274
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]	126	237
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]	126	237
Foreign Defined Benefit Plans | Certificates of deposit
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		2	3
Foreign Defined Benefit Plans | Certificates of deposit | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Certificates of deposit | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		2	3
Foreign Defined Benefit Plans | Certificates of deposit | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Unsecured debentures
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		5	10
Foreign Defined Benefit Plans | Unsecured debentures | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Unsecured debentures | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		5	10
Foreign Defined Benefit Plans | Unsecured debentures | 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		90	110
Foreign Defined Benefit Plans | Government debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		11	12
Foreign Defined Benefit Plans | Government debt securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		79	98
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]	1,753	2,451
Foreign Defined Benefit Plans | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[3]	218	215
Foreign Defined Benefit Plans | Mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[3]	1,535	2,236
Foreign Defined Benefit Plans | Mutual funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[3]	0	0
Foreign Defined Benefit Plans | Other debt securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		2	6
Foreign Defined Benefit Plans | Other debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Other debt securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		2	6
Foreign Defined Benefit Plans | Other debt securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Real estate
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[2]	74	103
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]	74	103
Foreign Defined Benefit Plans | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	1
Foreign Defined Benefit Plans | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	1
Foreign Defined Benefit Plans | Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Cash and cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		0	0
Foreign Defined Benefit Plans | Participant loans
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	[4]	37	52
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]	37	52
Foreign Defined Benefit Plans | Other assets
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		19	4
Foreign Defined Benefit Plans | Other assets | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets		16	0
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	$ 4

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

[2] (1) 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] (2) Mutual funds categorized as debt securities consist of mutual funds for which debt securities are the primary underlying investment.

[4] (3) Loans to participants are stated at cost, which approximates fair value.