Postretirement Benefits (Details 8) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012 participant	Dec. 31, 2011 participant
Amounts recognized in other comprehensive income for pension plans:
Amortization of net actuarial loss	$ (11)	$ (6)
Amortization of prior service cost	(1)	(1)
Net actuarial loss arising during the year	59	69
Amendments	0	1
Total recognized in other comprehensive income	$ 47	$ 63
Number of new plan participants	1	7

Before tax amount of the income statement impact of the reclassification adjustment for prior service costs recognized as a component of net period benefit cost.

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

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

+ Details