Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Summary of reconciliation of the ARO
Balance at beginning of period			$ 2,321	$ 2,149
Accretion expense	36	26	68	52
Additions during period			151	10
Balance at end of period	$ 2,540	$ 2,211	$ 2,540	$ 2,211