Supplemental Cash Flow Disclosure (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash paid during the period for:
Interest payments	$ 453	$ 533
Non-cash transactions:
Increase in net asset retirement obligations due to additions	198	55
Partner liabilities assumed in acquisition of partnership interests (see Note 3)	10
Increase (decrease) in accounts payable and accrued liabilities included in oil and gas properties	$ 2,340	$ (1,402)