Gas Reserves (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Gas Reserves [Abstract]
Amended Gas Reserves Agreement Date	Mar. 28, 2014
Cumulative gross investment Jonah Wells	$ 10,100	$ 500
Document Period End Date	Jun. 30, 2015
Gas Reserves, Current	$ 18,214	20,373	$ 20,020
Gas Reserves Noncurrent Gross	169,288	157,535	167,190
Gas Reserves Amortization	47,933	27,255	37,910
Total Gas Reserves	139,569	150,653	149,300
Deferred Taxes Related To Gas Reserves	27,357	34,828	18,551
Net investment in gas reserves	112,212	115,825	$ 130,749
Total gas reserves investment Jonah Wells	8,800	500
Net gas reserves investment Jonah Wells	$ 7,900	$ 500