Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011
Cash Flows from Operating Activities:
Net Income	$ 6,598	[1]	$ 61,209
Less (gain) from discontinued operations, net of taxes	0		(14,278)
Adjustments to reconcile net income to net cash provided by operation activities -
Depreciation, depletion, and amortization	122,651		108,737
Accretion of asset retirement obligation	2,274		2,299
Deferred income taxes	4,399		26,077
Stock-based compensation expenses	7,181		5,939
Other	(1,277)		(5,240)
Change in assets and liabilities-
Decrease in accounts receivable	12,501		1,682
Increase (decrease) in accounts payable and accrued liabilities	(3,313)		983
Decrease in income taxes payable	(198)		(217)
Increase (decrease) in accrued interest	4,863		(250)
Cash provided by operating activities - continuing operations	155,679		186,941
Cash provided by operating activities - discontinued operations	0		36
Net Cash Provided by Operating Activities	155,679		186,977
Cash Flows from Investing Activities:
Additions to property and equipment	(374,753)		(244,798)
Proceeds from the sale of property and equipment	284		51
Cash used in investing activities - continuing operations	(374,469)		(244,747)
Cash provided by investing activities - discontinued operations	0		5,000
Net Cash Used in Investing Activities	(374,469)		(239,747)
Cash Flows from Financing Activities:
Net proceeds from issuances of common stock	1,451		1,990
Purchase of treasury shares	(2,686)		(3,289)
Cash used in financing activities - continuing operations	(1,235)		(1,299)
Cash provided by financing activities - discontinued operations	0		0
Net Cash Used in Financing Activities	(1,235)		(1,299)
Net Decrease in Cash and Cash Equivalents	(220,025)		(54,069)
Cash and Cash Equivalents at Beginning of Period	251,696		86,367
Cash and Cash Equivalents at End of Period	31,671		32,298
Supplemental Disclosures of Cash Flows Information:
Cash paid during period for interest, net of amounts capitalized	20,698		16,171
Cash paid during period for income taxes	$ 198		$ 1,620

[1] Unaudited