Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ 191,000	$ (535,000)
Adjustments to reconcile net income to net cash provided by operating activities:
Depletion, depreciation and amortization	678,000	737,000
Impairment of oil and gas properties	285,000	32,000
Impairment of Inventory and Other Property and Equipment	1,000	5,000
Exploration expenses, including dry holes	18,000	40,000
Deferred income taxes	90,000	(284,000)
Gain on disposition of assets, net	(205,000)	(3,000)
Accretion of discount on asset retirement obligations	10,000	9,000
Interest expense	2,000	9,000
Derivative related activity	(251,000)	535,000
Amortization of stock-based compensation	43,000	44,000
Other	34,000	34,000
Change in operating assets and liabilities, net of effects from acquisitions and dispositions:
Accounts receivable, net	27,000	(51,000)
Income taxes receivable	2,000	39,000
Inventories	(11,000)	(12,000)
Derivatives	0	(12,000)
Increase Decrease in Investments	3,000	0
Other current assets	1,000	0
Accounts payable	(42,000)	(60,000)
Interest payable	(9,000)	20,000
Income taxes payable	0	(2,000)
Other current liabilities	(24,000)	(26,000)
Net cash provided by operating activities	843,000	519,000
Cash flows from investing activities:
Proceeds from disposition of assets, net of cash sold	345,000	2,000
Proceeds from Sale and Maturity of Held-to-maturity Securities	878,000	1,000
Purchase of investment securities	(746,000)	(1,495,000)
Additions to oil and gas properties	(1,074,000)	(971,000)
Additions to other assets and other property and equipment, net	(176,000)	(126,000)
Net cash used in investing activities	(773,000)	(2,589,000)
Cash flows from financing activities:
Principal payments on long-term debt	(485,000)	0
Proceeds from issuance of common stock, net of issuance costs	0	2,534,000
Purchases of treasury stock	(36,000)	(23,000)
Dividends paid	(7,000)	(7,000)
Net cash provided by (used in) financing activities	(528,000)	2,504,000
Net increase (decrease) in cash and cash equivalents	(458,000)	434,000
Cash and cash equivalents, beginning of period	1,118,000	1,391,000
Cash and cash equivalents, end of period	$ 660,000	$ 1,825,000