Impairments (Tables)

12 Months Ended

Dec. 31, 2014

Goodwill and Intangible Assets Disclosure [Abstract]

Details of Impairment of Long-Lived Assets Held and Used by Asset

The following table summarizes impairment charges recorded during the periods presented:

	Year Ended December 31,
	2014		2013		2012
Oil and gas properties	$	791,809	$	132,224	$	103,417
Other – tubular inventory and well materials	—		—		1,067
	$	791,809	$	132,224	$	104,484

Fair Value Measurements, Nonrecurring

The following table summarizes the aggregate fair values of the assets described below, by asset category and the classification of inputs within the fair value measurement hierarchy, at the respective dates of impairment:

	Fair Value
	Measurement		Level 1		Level 2		Level 3
Year ended December 31, 2014:
Long-lived assets held for use	$	65,203	$	—	$	—	$	65,203
Long-lived assets sold during the year	70,733		—		—		70,733
Year ended December 31, 2013:
Long-lived assets held for use	$	93,945	$	—	$	—	$	93,945
Year ended December 31, 2012:
Long-lived assets held for use	$	14,801	—		—		14,801
Long-lived assets sold during the year	96,099		—		—		96,099