Income and Partnership Taxes Unrecognized Tax Benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 1,100	$ 0
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	1,100
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions		0
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	0
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	$ 0