Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Other Comprehensive Income [Abstract]
Net Income	$ 8,886	$ 3,122	$ 22,817	$ 9,720
Other Comprehensive Income:
Unrealized gains (losses) related to price risk management transactions, before taxes	0	66	0	1,237
Provision (benefits) for income taxes	0	24	0	450
Unrealized gains (losses) related to price risk management transactions, net of taxes	0	42	0	787
Less: reclassification of (gains) losses on price risk management transactions to net income, before taxes	0	(244)	0	(1,415)
(Provision) benefit for income taxes	0	(89)	0	(515)
Reclassification of (gains) losses on price risk management transactions to net income, net of taxes	0	(155)	0	(900)
Other comprehensive income (loss), before income taxes	0	(178)	0	(178)
Provision (benefit) for income taxes	0	(65)	0	(65)
Other comprehensive income (loss), net of taxes	0	(113)	0	(113)
Comprehensive Income	$ 8,886	$ 3,009	$ 22,817	$ 9,607