Organization and Significant Accounting Policies (Details) (USD $)	3 Months Ended						12 Months Ended
	Dec. 31, 2013 region	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2013 region	Dec. 31, 2012	Dec. 31, 2011
Nature of operations [Abstract]
Number of operating regions in domicile country	3						3
Accounts Receivable [Abstract]
Allowance for doubtful accounts	$ 407,000			$ 105,000			$ 407,000	$ 105,000
Oil and gas properties, full cost method of accounting:
Discount rate used in future net cash flows relating to proved oil and gas reserves (in hundredths)							10.00%
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Write downs of oil and gas properties	3,900,000	100,000	2,000,000	6,700,000	11,800,000	1,300,000
Share-Based Payments [Abstract]
Stock-based compensation expense							2,114,000	2,091,000	1,987,000
Entity's asset retirement obligation transactions [Roll Forward]
Beginning asset retirement obligation							11,381,000	8,412,000
New wells placed on production and other							222,000	330,000
Deletions related to property disposals and plugging costs							(2,491,000)	(423,000)
Accretion expense							(638,000)	(474,000)	(452,000)
Revisions							138,000	2,588,000
Ending asset retirement obligation	9,888,000			11,381,000			9,888,000	11,381,000	8,412,000
Revenue Recognition and Major Purchasers [Abstract]
Entity wide revenue, major customers (in hundredths)							49.00%	39.00%	28.00%
Entity wide revenue, number of major purchasers of oil and gas							2	3	2
Income Taxes [Abstract]
Valuation allowance for deferred tax assets	75,566,000			89,712,000			75,566,000	89,712,000	83,481,000
Canada [Member]
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Exceeded amount of net capitalized cost over estimated proved reserves	$ 6,000,000			$ 19,800,000			$ 6,000,000	$ 19,800,000