Costs Incurred for Property Acquisition, Exploration and Development (Tables)

3 Months Ended

Mar. 31, 2019

Extractive Industries [Abstract]

Costs Incurred for Property Acquisition, Exploration and Development

	Three Months Ended March 31, 2019		Year Ended December 31, 2018
	(in thousands)
Acquisitions:
Acreage purchases	$	14,634	$	62,390
Oil and gas properties		—		1,683
Development		209,827		834,552
Exploration:
Drilling		542		1,380
Expense		7,837		32,196
Stock-based compensation expense		373		1,921
Gas gathering facilities:
Development		1,063		10,218
Subtotal		234,276		944,340
Asset retirement obligations		1,532		28,826
Total costs incurred	$	235,808	$	973,166

^(a) Includes costs incurred whether capitalized or expensed.