Pension and Other Postemployment Benefits (Details Textuals) (USD $)		12 Months Ended
	Jun. 30, 2012 Allegheny	Dec. 31, 2012 Pensions	Dec. 31, 2011 Pensions	Dec. 31, 2012 Pensions Qualified Plan	Dec. 31, 2012 OPEB	Dec. 31, 2011 OPEB
Defined Benefit Plan Disclosure [Line Items]
Plan amendments		$ (8,000,000)	$ 0		$ 85,000,000	$ 98,000,000
Pre-tax contributions to qualified plans		614,000,000	384,000,000	600,000,000	19,000,000	19,000,000
Net assets merged	1,100,000,000
Estimated 2013 amortization of prior service costs (credits) from AOCI		$ 12,000,000			$ (201,000,000)