Postemployment Benefits Weighted Average Assumptions Used for Benefit Costs (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Health and Welfare [Member]
Postemployment and Other Postretirement Benefit Plans [Line Items]
Discount rate	4.00%	5.25%
Postemployment Benefits [Member]
Postemployment and Other Postretirement Benefit Plans [Line Items]
Discount rate	8.00%	8.25%
Rate of compensation increase	4.50%	4.50%