Pension and Other Postemployment Benefits (Details 2)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pensions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average discount rate	5.00%	5.50%	6.00%
Expected long-term return on plan assets	7.75%	8.25%	8.50%
Rate of compensation increase	5.20%	5.20%	5.20%
OPEB
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average discount rate	4.75%	5.00%	5.75%
Expected long-term return on plan assets	7.75%	8.50%	8.50%