Pension and Other Postretirement Benefits (Details 5)	12 Months Ended
	Dec. 31, 2012
US Plan [Member]
Plans weighted-average allocations by asset category
Weighted-average allocations by asset category	100.00%
Canadian Plan [Member]
Plans weighted-average allocations by asset category
Weighted-average allocations by asset category	100.00%
Equities [Member] | US Plan [Member]
Plans weighted-average allocations by asset category
Weighted-average allocations by asset category	58.00%
Equities [Member] | Canadian Plan [Member]
Plans weighted-average allocations by asset category
Weighted-average allocations by asset category	39.00%
Fixed income [Member] | US Plan [Member]
Plans weighted-average allocations by asset category
Weighted-average allocations by asset category	42.00%
Fixed income [Member] | Canadian Plan [Member]
Plans weighted-average allocations by asset category
Weighted-average allocations by asset category	61.00%