Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Activities
Net income	$ 126,917	$ 37,172	$ 13,941
Adjustments to reconcile net income to net cash provided by operating activities:
Depletion, depreciation, accretion and impairment (Note 6)	231,235	163,573	135,863
Deferred taxes (Note 9)	(29,222)	(20,090)	(15,355)
Stock-based compensation (Note 7)	12,767	8,025	5,309
(Gain) loss on financial instruments (Notes 3 and 12)	(1,354)	(44)	277
Unrealized foreign exchange (gain) loss	(1,695)	14,786	19,496
Settlement of asset retirement obligation (Note 8)	(345)	(286)	(52)
Equity tax	2,442	0	0
Gain on acquisition (Note 3 and 12)	(21,699)	0	0
Net changes in non-cash working capital
Accounts receivable	(15,627)	(5,323)	(27,926)
Inventory	(548)	(1,221)	(1,849)
Prepaids	(1,321)	(120)	(717)
Accounts payable and accrued liabilities	19,918	(3,212)	36,875
Taxes receivable and payable	35,422	10,522	(409)
Net cash provided by operating activities	356,890	203,782	165,453
Investing Activities
Restricted cash	(10,197)	352	(1,792)
Additions to property, plant and equipment	(333,194)	(152,299)	(80,932)
Proceeds from disposition of oil and gas properties (Note 6)	4,450	7,986	5,400
Cash acquired on acquisition (Note 3)	7,747	0	0
Proceeds on sale of asset-backed commercial paper (Note 3)	22,679	0	0
Long term assets and liabilities	(3,138)	36	968
Net cash used in investing activities	(311,653)	(143,925)	(76,356)
Financing Activities
Settlement of bank debt (Notes 3 and 13)	(54,103)	0	0
Proceeds from issuance of common shares	5,123	24,785	4,935
Net cash (used in) provided by financing activities	(48,980)	24,785	4,935
Net (decrease) increase in cash and cash equivalents	(3,743)	84,642	94,032
Cash and cash equivalents, beginning of year	355,428	270,786	176,754
Cash and cash equivalents, end of year	351,685	355,428	270,786
Cash	172,645	272,151	182,197
Term deposits	179,040	83,277	88,589
Cash and cash equivalents, end of year	351,685	355,428	270,786
Supplemental cash flow disclosures:
Cash paid for interest	1,604	0	0
Cash paid for taxes	67,053	49,088	31,527
Non-cash investing activities:
Non-cash working capital related to property, plant and equipment	$ 43,333	$ 48,640	$ 17,972