STOCK-BASED COMPENSATION (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Options, Restricted Stock and Unit Awards
Compensation cost before capitalized cost	$ 11,992	$ 10,514
Less amounts capitalized to oil and gas properties	(5,704)	(4,986)
Compensation expense	6,288	5,528
Retained earnings (Accumulated deficit)	(562,645)		$ (722,359)
Additional paid-in capital	2,771,296		$ 2,763,452
Net cash (used) provided by financing activities	(8,505)	(15,335)
Net cash provided by operating activities	249,514	85,405
Restricted Stock [Member]
Options, Restricted Stock and Unit Awards
Compensation cost before capitalized cost	11,326	9,859
Performance Based Restricted Stock [Member]
Options, Restricted Stock and Unit Awards
Compensation cost before capitalized cost	6,402	5,694
Service Based Restricted Stock [Member]
Options, Restricted Stock and Unit Awards
Compensation cost before capitalized cost	4,924	4,165
Employee Stock Option [Member]
Options, Restricted Stock and Unit Awards
Compensation cost before capitalized cost	666	655
Accounting Standards Update 2016 09 [Member]
Options, Restricted Stock and Unit Awards
Deferred income taxes	33,100
Retained earnings (Accumulated deficit)	28,700
Additional paid-in capital	$ 4,400
Net cash (used) provided by financing activities		300
Net cash provided by operating activities		$ 300

Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences, with jurisdictional netting and classified as noncurrent.

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Amount of cash inflow (outflow) of financing activities, excluding discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from operating activities, excluding discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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The cumulative amount of the reporting entity's undistributed earnings or deficit.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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