Financial Instruments (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Fair value of financial instruments, details:
Carrying amount of long-term debt	$ 32,821				$ 32,821				$ 32,856
Fair value of long-term debt	35,165				35,165				34,555
Debt and Marketable Equity Securities.
Debt securities - noncurrent, Adjusted Cost	7	[1]			7	[1]			7	[1]
Debt securities - noncurrent, gross unrealized gains	2	[1]			2	[1]			1	[1]
Available-for-sale equity investments, Adjusted Cost	6	[1]			6	[1]			20	[1]
Available-for-sale equity investments, gross unrealized gains	2	[1]			2	[1]			2	[1]
Available-for-sale equity investments, gross unrealized losses	0	[1]			0	[1]			4	[1]
Debt securities - noncurrent	9	[1]			9	[1]			9	[1]
Available-for-sale equity investments	7	[1]			7	[1]			18	[1]
Sales of debt and available-for-sale equity investments
Proceeds	1		8		16		28
Gross realized gains (before taxes)	0		5		0		9
Gross realized losses (before taxes)	0		0		5		4
Unrealized holding gains/(losses) on available-for-sale debt and equity securities
Net unrealized gains/(losses) arising during the period	0		3		1		2
Net unrealized (gains)/losses reclassified to net income	0	[2]	(3)	[2]	3	[2]	(3)	[2]
Writedowns included in net income for the period	0		0		0		0
Maximum contractual maturities of substantially all available-for-sale debt securities					1 year
Other (income) and expense
Debt and Marketable Equity Securities.
Trading securities, unrealized gains					8
Trading securities, unrealized losses	$ 8

[1] Included within investments and sundry assets in the Consolidated Statement of Financial Position.

[2] There were no writedowns for the nine months ended September 30, 2014 and 2013, respectively.