17. Supplemental Oil and Gas Disclosures

The supplemental data presented below reflects information for all of the Company's oil and natural gas producing activities.

Capitalized Costs

The following table sets forth the capitalized costs related to the Company's oil and natural gas producing activities at December 31, 2011 and 2010:

		September 30,			September 30,
	December 31,
	2011			2010
	(In thousands)
Proved oil and gas properties	$	1,152,532		$	479,657
Less: Accumulated depreciation, depletion, amortization and impairment		(174,948	)		(98,821	)

Proved oil and gas properties, net		977,584			380,836
Unproved oil and gas properties		82,825			101,311

Total oil and gas properties, net	$	1,060,409		$	482,147

Pursuant to the FASB's authoritative guidance on ARO, net capitalized costs include asset retirement costs of $11.4 million and $6.3 million at December 31, 2011 and 2010, respectively.

Costs Incurred in Oil and Natural Gas Property Acquisition, Exploration and Development Activities

The following table sets forth costs incurred related to the Company's oil and natural gas activities for the years ended December 31, 2011, 2010 and 2009:

		September 30,		September 30,		September 30,
	Year Ended December 31,
	2011		2010		2009
	(In thousands)
Acquisition costs:
Proved oil and gas properties	$	3,356	$	20,259	$	35,134
Unproved oil and gas properties		15,197		81,624		13,917
Exploration costs		1,685		297		1,019
Development costs		618,737		243,758		38,526
Asset retirement costs		5,055		968		1,314

Total costs incurred	$	644,030	$	346,906	$	89,910

Results of Operations for Oil and Natural Gas Producing Activities

Results of operations for oil and natural gas producing activities, which excludes straight-line depreciation, general and administrative expenses and interest expense, are presented below.

		September 30,		September 30,		September 30,
	December 31,
	2011		2010		2009
	(In thousands)
Revenues	$	330,422	$	128,927	$	37,755
Production costs		67,937		28,350		12,501
Depreciation, depletion and amortization		74,101		37,583		16,592
Exploration costs		1,685		297		1,019
Rig termination(1)		—		—		3,000
Impairment of oil and gas properties		3,610		11,967		6,233
Loss (gain) on sale of properties		207		—		(1,455	)
Income tax expenses		64,009		17,756		—

Results of operations for oil and gas producing activities	$	118,873	$	32,974	$	(135	)

(1)	During the first quarter of 2009, we paid a total of $3.0 million in rig termination expenses in connection with early termination of two drilling rig contracts entered into in 2008. We did not have any rig termination expenses during the years ended December 31, 2011 and 2010.