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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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The percentage rate used to calculate dividend payments on preferred stock.

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ACQUISITIONS AND DIVESTITURES-Pecos County Acquisition (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		9 Months Ended
	Feb. 28, 2017	Jan. 24, 2017	Jan. 18, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Pro forma financial information
Net income (loss) available to common stockholders				$ (81,837)	$ 419,287	$ (100,709)	$ 580,809
8% Convertible Preferred Stock
ACQUISITIONS AND DIVESTITURES
Dividend rate (as a percent)		8.00%	8.00%
Pecos County Assets
ACQUISITIONS AND DIVESTITURES
Purchase price	$ 699,200
Pro forma financial information
Revenue							360,590
Net income (loss)							635,854
Net income (loss) available to common stockholders							$ 587,847
Pro forma net income (loss) per share of common stock:
Basic (in dollars per share)							$ 4.61
Diluted (in dollars per share)							$ 4.58