Changes in Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Abstract]
AOCI, Post-employment benefts, net of tax	$ (670)			$ (692)
AOCI, Hedge instruments, net of tax	(25)			(26)
AOCI, Translation adjustments and other, net of tax	(703)			(575)
Accumulated other comprehensive loss, net of tax	(1,398)			(1,293)
OCI, Post-employment benefts before reclassificaitons, net of tax	14
OCI, Hedge instruments before reclassificaitons, net of tax	1
OCI, Translation adjustments and other before reclassificaitons, net of tax	(109)
Other comprehensive income, before reclassifications to income	(94)
OCI, Post-employment benefts reclassificaitons to income, net of tax	8	[1]
OCI, Hedge instruments reclassificaitons to income, net of tax	0	[1]
OCI, Translation adjustments and other reclassificaitons to income, net of tax	(19)	[1]
Other comprehensive income, portion representing reclassificaitons to earnings	(11)	[1]
OCI, Post-employment benefts, net of tax	22		2
OCI, Hedge instruments, net of tax	1		0
OCI, Translation adjustments and other, net of tax	(128)		(5)
Other comprehensive loss, net of tax	$ (105)		$ (3)

[1] See Note 11, "Pension, Other Post-employment Benefits and Employee Benefit Plans," and Note 6, "Financial Instruments," for additional information with respect to reclassifications from accumulated other comprehensive loss to earnings relating to post-employment benefits, net of tax and hedge instruments, net of tax, respectively. Such items do not represent reclassifications in their entirety. During the first quarter of 2015, our Energy segment reclassified from accumulated other comprehensive loss to earnings for the sale of certain available-for-sale securities as well as the impact of transferring balances in available-for-sale securities to trading securities. See Note 4, "Investments and Related Matters - Other Segments," for further discussion.