Summary Of Significant Accounting Policies (Schedule Of Segment's Revenues) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Valero Energy Corporation | Oil and Natural Gas [Member]
Revenue, Major Customer [Line Items]
Segment's revenues	25.30%	26.00%	18.00%
Sunoco Partners Marketing | Oil and Natural Gas [Member]
Revenue, Major Customer [Line Items]
Segment's revenues	7.50%	8.00%	10.00%
QEP Resources, Inc. | Drilling [Member]
Revenue, Major Customer [Line Items]
Segment's revenues	18.00%	15.00%	22.00%
Kodiak Oil and Gas Corp. | Drilling [Member]
Revenue, Major Customer [Line Items]
Segment's revenues	10.00%	10.00%	6.00%
ONEOK, Inc. | Mid-Stream [Member]
Revenue, Major Customer [Line Items]
Segment's revenues	50.19%	54.00%	54.00%
Tenaska Resources, LLC | Mid-Stream [Member]
Revenue, Major Customer [Line Items]
Segment's revenues	16.37%	7.00%	1.38%
Gavilon, LLC | Mid-Stream [Member]
Revenue, Major Customer [Line Items]
Segment's revenues	0.00%	10.00%	19.00%