Stock Compensation Plans and Other Compensation Arrangements (Details) (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		3 Months Ended
Mar. 31, 2012 Restricted Stock Rights	Mar. 31, 2012 Restricted Performance Stock Rights	Feb. 15, 2012 Restricted Stock Rights and Restricted Performance Stock Rights [Member]	Mar. 31, 2012 Cash Units	Mar. 31, 2012 Cash Performance Units	Feb. 15, 2012 Minimum Cash Units and Cash Performance Units [Member]	Feb. 15, 2012 Maximum Cash Units and Cash Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, cash units, or cash performance units granted	0.5	1.2		0.6	1.3
Unrecognized compensation expense related to unvested awards			$ 102			$ 34	$ 190
Vesting period of stock awards	3 years	3 years		3 years	3 years

Description of the period of time over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, which may be expressed in a variety of ways (for example, in years, month and year).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Balance Type:	na
Period Type:	duration