Oil and Natural Gas Capitalized Costs (Tables)

9 Months Ended

Sep. 30, 2011

Oil And Gas Exploration And Production Industries Disclosures [Abstract]

Aggregate Capitalized Costs Related to Oil, Natural Gas and NGL Production Activities

Aggregate capitalized costs related to oil, natural gas and NGL production activities with applicable accumulated depletion and amortization are presented below:

	September 30, 2011			December 31, 2010
	(in thousands)
Proved properties:
Leasehold acquisition	$	5,483,984		$	4,695,704
Development		1,262,251			840,175
Unproved properties		194,543			128,624
		6,940,778			5,664,503
Less accumulated depletion and amortization		(939,264	)		(719,035	)
	$	6,001,514		$	4,945,468