Summary of Significant Accounting Policies, Derivatives by Hedging Relationship and Fair Value Measurements (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Company's asset retirement obligations [Roll Forward]
Balance on January 1,	$ 1,568,000	$ 1,390,000
Liabilities incurred	358,000	164,000
Accretion of discount	63,000	82,000
Liabilities settled	(103,000)	(68,000)
Revisions to estimates	0	0
Balance on December 31,	1,886,000	1,568,000
Escrow cash	75,000
Level 1 Quoted Prices [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Value	299,000	780,000
Factors impacting the change in the net value of the Company's fair value contracts [Abstract]
Net Fair Value January 1,	780,000	(118,000)
Net realized (gains) losses	(780,000)	118,000
Net unrealized gains (losses)	299,000	780,000
Net Fair Value December 31,	299,000	780,000
Level 2 Observable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Value	(293,000)	603,000
Factors impacting the change in the net value of the Company's fair value contracts [Abstract]
Net Fair Value January 1,	603,000	1,404,000
Net realized (gains) losses	(603,000)	(1,404,000)
Net unrealized gains (losses)	(293,000)	603,000
Net Fair Value December 31,	(293,000)	603,000
Total Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Value	6,000	1,383,000
Factors impacting the change in the net value of the Company's fair value contracts [Abstract]
Net Fair Value January 1,	1,383,000	1,286,000
Net realized (gains) losses	(1,383,000)	(1,286,000)
Net unrealized gains (losses)	6,000	1,383,000
Net Fair Value December 31,	6,000	1,383,000
Fair Value, Measurements, Recurring [Member] | Level 1 Quoted Prices [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - Current assets	299,000	1,455,000
Derivatives - Current liabilities	0	(675,000)
Net Value	299,000	780,000
Factors impacting the change in the net value of the Company's fair value contracts [Abstract]
Net Fair Value December 31,	299,000	780,000
Fair Value, Measurements, Recurring [Member] | Level 2 Observable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - Current assets	389,000	2,045,000
Derivatives - Current liabilities	(682,000)	(1,442,000)
Net Value	(293,000)	603,000
Factors impacting the change in the net value of the Company's fair value contracts [Abstract]
Net Fair Value December 31,	(293,000)	603,000
Fair Value, Measurements, Recurring [Member] | Level 3 Unobservable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - Current assets	0	0
Derivatives - Current liabilities	0	0
Net Value	0	0
Factors impacting the change in the net value of the Company's fair value contracts [Abstract]
Net Fair Value December 31,	0	0
Fair Value, Measurements, Recurring [Member] | Counterparty Offsets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - Current assets	(270,000)	(1,436,000)
Derivatives - Current liabilities	270,000	1,436,000
Net Value	0	0
Factors impacting the change in the net value of the Company's fair value contracts [Abstract]
Net Fair Value December 31,	0	0
Fair Value, Measurements, Recurring [Member] | Total Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - Current assets	418,000	2,064,000
Derivatives - Current liabilities	(412,000)	(681,000)
Net Value	6,000	1,383,000
Factors impacting the change in the net value of the Company's fair value contracts [Abstract]
Net Fair Value December 31,	6,000	1,383,000
Commodity Contract [Member] | Revenues - marketing [Member] | Not Designated as Hedging Instrument [Member]
Earnings (loss) recognized in income [Abstract]
Gain (Loss)	$ (1,377,000)	$ 97,000	$ 1,036,000