Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Segment Information (Unaudited) (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Change in Accounting Estimate [Line Items]
Operating Income (Loss)	$ 794	$ 769	$ 2,387	$ 2,434
Change in Assumptions for Pension Plans [Member]
Change in Accounting Estimate [Line Items]
Operating Income (Loss)		$ (132)