Segment Information (Tables)

3 Months Ended

Mar. 31, 2013

Segment Information [Abstract]

Summary Financial Information for Company's Reportable Segments Table

	Exploration
	and		Midstream
	Production		Services		Other			Total
	(in thousands)
Three months ended March 31, 2013:
Revenues from external customers	$	510,094	$	223,534	$	21		$	733,649
Intersegment revenues		1,508		497,373		54			498,935
Operating income (loss)		175,758		76,307		(105)			251,960
Other loss, net(1)		(378)		(155)		–			(533)
Commodity derivative loss		(29,794)		–		–			(29,794)
Depreciation, depletion and amortization expense		167,450		11,912		105			179,467
Interest expense(1)		6,176		2,645		200			9,021
Provision (benefit) for income taxes(1)		55,816		29,403		(122)			85,097
Assets		5,389,728		1,278,256		248,807	(2)		6,916,791
Capital investments(3)		475,333		38,467		4,256			518,056
Three months ended March 31, 2012:
Revenues from external customers	$	464,631	$	190,173	$	31		$	654,835
Intersegment revenues		713		356,281		819			357,813
Operating income		114,609		69,289		428			184,326
Other income (loss), net(1)		(183)		(18)		1			(200)
Commodity derivative income		1,634		–		–			1,634
Depreciation, depletion and amortization expense		182,739		10,570		318			193,627
Interest expense(1)		3,322		3,667		349			7,338
Provision for income taxes(1)		44,838		25,848		32			70,718
Assets		7,038,247		1,087,020		428,894	(2)		8,554,161
Capital investments(3)		533,139		26,164		13,809			573,112

(1)  Interest expense and the provision for income taxes by segment are allocated as they are incurred at the corporate level.

(2) Other assets represent corporate assets not allocated to segments and assets, including restricted cash and investments in cash equivalents, for non-reportable segments.

(3)Capital investments includes increases of $32.9 million and $15.3 million for the three-month periods ended March 31, 2013 and 2012, respectively, relating to the change in accrued expenditures between periods.