Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating activities:
Net income (loss)	$ 71,171	$ (193,397)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depletion, depreciation and accretion	42,584	47,911
Impairment of Oil and Gas Properties	135	0
Deferred income tax expense (benefit)	8,455	17,833
Non-cash (gain) loss from hedging and derivative activities	6,731	(12,223)
Stock-based compensation	9,146	13,699
Non-cash interest expense	8,441	23,643
Fortune Creek accretion	11,605	14,490
Other	(347)	3,622
Changes in assets and liabilities
Accounts receivable	(1,936)	7,398
Prepaid expenses and other assets	1,747	344
Accounts payable	(12,472)	(17,973)
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable	(432)	(148)
Accrued and other liabilities	(7,469)	(31,950)
Net cash flow provided by (used in) by operating activities	(4,983)	(81,103)
Investing activities:
Purchases of property, plant and equipment	(111,444)	(78,549)
Proceeds from sale of properties and equipment	1,942	2,994
Payments to acquire marketable securities	(55,890)	(142,823)
Proceeds from Sale and Maturity of Held-to-maturity Securities	222,025	13,178
Net cash provided by (used in) investing activities	152,220	300,515
Financing activities:
Issuance of debt	243,184	1,173,306
Repayments of debt	(193,689)	(1,308,382)
Debt issuance costs paid	(225)	(25,868)
Distribution of Fortune Creek Partnership funds	(37,113)	(8,079)
Purchase of treasury stock	(2,388)	(1,472)
Net cash provided by financing activities	9,769	(170,495)
Effect of exchange rate changes in cash	2,216	2,610
Net increase (decrease) in cash	159,222	51,527
Cash at beginning of period	89,103	4,951
Cash at end of period	248,325	56,478
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	(341,146)
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	95,587	0
Synergy [Member]
Investing activities:
Proceeds from Divestiture of Interest in Subsidiaries and Affiliates	$ 0	$ 42,297