Acquisition of Southwest Royalties, Inc. Limited Partnerships (Tables)

12 Months Ended

Dec. 31, 2012

Business Combinations [Abstract]

Summary of estimated fair value of the assets acquired and liabilities assumed

The following table summarizes the estimated fair value of the assets acquired and liabilities assumed at the date of acquisition (in thousands):

Cash and cash equivalents	$	4,118
Oil and gas properties	41,098
Other non-current assets	210
Total assets acquired	45,426
Asset retirement obligations	(6,864		)
Total liabilities assumed	(6,864		)
Net assets acquired	$	38,562