Nature of operations and summary of significant accounting policies Nature of operations and summary of significant accounting policies (Tables)

6 Months Ended

Jun. 30, 2014

Accounting Policies [Abstract]

Components of accounts receivable

Accounts receivable consisted of the following at June 30, 2014 and December 31, 2013:

	June 30, 2014			December 31, 2013
Joint interests	$	32,971		$	31,335
Accrued commodity sales	77,334			60,768
Derivative settlements	—			4,616
Production tax credit	2,031			694
Other	1,354			698
Allowance for doubtful accounts	(325		)	(1,596		)
	$	113,365		$	96,515

Components of inventory

Inventories at June 30, 2014 and December 31, 2013 consisted of the following:

	June 30, 2014			December 31, 2013
Equipment inventory	$	19,457		$	13,657
Commodities	2,751			3,186
Inventory valuation allowance	(779		)	(706		)
	$	21,429		$	16,137