Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities:
Net income (loss)	$ 94,928	$ (182,818)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depletion, depreciation and accretion	28,615	33,521
Deferred income tax expense (benefit)	6,020	11,497
Non-cash loss from hedging and derivative activities	45,119	9,135
Stock-based compensation	5,577	11,163
Non-cash interest expense	5,840	21,773
Fortune Creek accretion	8,003	9,672
Other	(163)	1,548
Changes in assets and liabilities
Accounts receivable	(17,909)	19,264
Prepaid expenses and other assets	456	(1,195)
Accounts payable	(12,725)	(16,443)
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable	6,978	(329)
Accrued and other liabilities	18,354	(27,358)
Net cash flow provided by (used in) by operating activities	(763)	(78,106)
Investing activities:
Purchases of property, plant and equipment	(87,992)	(55,849)
Proceeds from sale of properties and equipment	1,810	1,681
Payments to acquire marketable securities	(55,890)	(118,656)
Proceeds from Sale and Maturity of Held-to-maturity Securities	212,057	0
Net cash provided by (used in) investing activities	163,441	290,594
Financing activities:
Issuance of debt	0	1,173,306
Repayments of debt	(193,689)	(1,264,117)
Debt issuance costs paid	(225)	(25,608)
Distribution of Fortune Creek Partnership funds	(33,770)	(5,009)
Purchase of treasury stock	(2,383)	(1,125)
Net cash provided by financing activities	(230,067)	(122,553)
Effect of exchange rate changes in cash	570	1,907
Net increase (decrease) in cash	(66,819)	91,842
Cash at beginning of period	89,103	4,951
Cash at end of period	22,284	96,793
Tokyo Gas [Member]
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Gain (Loss) on Disposition of Oil and Gas and Timber Property	0	(333,172)
Investing activities:
Proceeds from Divestiture of Interest in Subsidiaries and Affiliates	0	463,418
Sandwash Basin [Member]
Investing activities:
Proceeds from Divestiture of Interest in Subsidiaries and Affiliates	$ 93,456	$ 0