CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Operating activities:
Net earnings (loss)	$ (543,846)	$ 35,644
Less: net earnings from discontinued operations	0	16,461
Net earnings (loss) from continuing operations	(543,846)	19,183
Adjustments to reconcile net earnings (loss) from continuing operations to net cash provided by operating activities of continuing operations:
Depreciation, depletion, and amortization	139,957	100,904
Deferred income tax	167,880	13,340
Unrealized (gains) losses on derivative instruments, net	(5,423)	14,010
Ceiling test write-down of oil and natural gas properties	383,793	0
Stock-based compensation expense	9,257	8,077
Accretion of asset retirement obligations	3,195	2,957
Other, net	4,638	4,059
Changes in operating assets and liabilities:
Accounts receivable	19,077	32,941
Other current assets	2,305	10,441
Accounts payable and accrued liabilities	(20,601)	(8,623)
Accrued interest and other current liabilities	16,192	(3,640)
Net cash provided by operating activities of continuing operations	176,424	193,649
Capital expenditures for property and equipment:
Exploration, development, and leasehold acquisition costs	(395,781)	(374,638)
Other fixed assets	(4,910)	(3,559)
Proceeds from sales of assets	1,102	120,634
Net cash used by investing activities of continuing operations	(399,589)	(257,563)
Financing activities:
Proceeds from bank borrowings	443,000	12,000
Repayments of bank borrowings	(200,000)	(12,000)
Payment of debt issue costs	0	(7,924)
Change in bank overdrafts	(20,666)	14,353
Other, net	(1,501)	(4,488)
Net cash provided by financing activities of continuing operations	220,833	1,941
Cash flows of discontinued operations:
Operating cash flows	0	57,234
Investing cash flows	0	(205,274)
Financing cash flows	0	474,367
Net cash provided by discontinued operations	0	326,327
Effect of exchange rate changes on cash	0	(3,350)
Net (decrease) increase in cash and cash equivalents	(2,332)	261,004
Net increase in cash and cash equivalents of discontinued operations	0	(4,434)
Net (decrease) increase in cash and cash equivalents of continuing operations	(2,332)	256,570
Cash and cash equivalents of continuing operations at beginning of period	3,012	217,569
Cash and cash equivalents of continuing operations at end of period	680	474,139
Cash paid by continuing operations during the period for:
Interest (net of capitalized amounts)	61,622	70,807
Income taxes (net of refunded amounts)	915	31,029
Non-cash investing activities of continuing operations:
Increase in accrued capital expenditures	5,672	59,520
Increase in asset retirement costs	2,453	921
Common stock issued for acquisition of unproved oil and natural gas properties	$ 36,431	$ 0