Costs of Oil and Gas Properties (Tables)

12 Months Ended

Dec. 31, 2014

Oil and Gas Property, Successful Effort Method, Gross [Abstract]

Costs incurred in connection with the company's oil and gas producing activities

The following table sets forth certain information with respect to costs incurred in connection with the Company’s oil and gas producing activities during the years ended December 31, 2014, 2013 and 2012.

	2014		2013		2012
	(In thousands)
Property acquisitions:
Proved	$	—	$	—	$	41,098
Unproved	56,327		50,104		72,235
Developmental costs	342,716		218,341		349,972
Exploratory costs	4,350		3,932		10,898
Total	$	403,393	$	272,377	$	474,203

Schedule of net capitalized costs for oil and gas properties

The following table sets forth the net capitalized costs for oil and gas properties as of December 31, 2014 and 2013.

	2014			2013
	(In thousands)
Proved properties	$	2,585,279		$	2,317,053
Unproved properties	99,634			86,224
Total capitalized costs	2,684,913			2,403,277
Accumulated depletion	(1,430,699		)	(1,282,989		)
Net capitalized costs	$	1,254,214		$	1,120,288