Oil and Gas Producing Activities

12 Months Ended

Dec. 31, 2015

Oil And Gas Exploration And Production Industries Disclosures [Abstract]

Oil and Gas Producing Activities

(3) Oil and Gas Producing Activities

Set forth below is certain information regarding the aggregate capitalized costs of oil and gas properties and costs incurred by the Company for its oil and gas property acquisition, development and exploration activities:

Capitalized Costs

	As of December 31,
	2014			2015
	(In thousands)
Unproved properties	$	201,459		$	84,144
Proved properties:
Leasehold costs		1,006,839			982,915
Wells and related equipment and facilities		3,275,249			3,349,307
Accumulated depreciation depletion and amortization		(2,298,450	)		(3,389,786	)
	$	2,185,097		$	1,026,580

Costs Incurred

	For the Years Ended December 31,
	2013		2014		2015
	(In thousands)
Property Acquisitions:
Unproved property acquisitions	$	130,113	$	91,960	$	12,972
Proved property acquisitions		6,471		2,400		—
Development costs		341,970		440,848		221,265
Exploration costs		439		52,080		12,265
	$	478,993	$	587,288	$	246,502