Pension, Postretirement and Postemployment Benefits (Details 3) (Pension Benefits)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Cash
Weighted-average asset allocations of Pool Pension Plan
Weighted-average asset allocations	3.00%	2.00%
Available-for-sale equity securities
Weighted-average asset allocations of Pool Pension Plan
Weighted-average asset allocations	55.00%	56.00%
Securities investment target allocation percentage	55.00%
Available-for-sale debt securities
Weighted-average asset allocations of Pool Pension Plan
Weighted-average asset allocations	42.00%	42.00%
Securities investment target allocation percentage	45.00%
Total investments
Weighted-average asset allocations of Pool Pension Plan
Weighted-average asset allocations	100.00%	100.00%