CONCENTRATION OF RISK Customer Constituting 10% or more of Total Revenue (Details)	12 Months Ended
	Dec. 31, 2013 Rate	Dec. 31, 2012 Rate	Dec. 31, 2011 Rate
Suncor Energy Marketing, Inc. [Member]
Concentration Risk [Line Items]
Percentage of Revenue	31.30%	29.80%	25.70%
Percentage of Accounts Receivable Balance at Year-End	26.30%
DCP Midstream, LP [Member]
Concentration Risk [Line Items]
Percentage of Revenue	14.60%	12.20%	11.50%
Percentage of Accounts Receivable Balance at Year-End	10.80%