CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Consolidated Statements of Operations
Revenues	$ 293,240	$ 439,994	$ 986,412	$ 1,344,254
Cost of revenues (exclusive of items shown below)	225,230	300,947	742,713	908,631
Selling, general and administrative expenses	42,571	41,787	131,285	128,135
Impairment and other charges	71,650		71,650
Depreciation and amortization	44,701	42,993	130,087	120,567
Loss (gain) on disposition of assets, net	1,727	(286)	(2,910)	(3,459)
Operating (loss) income	(92,639)	54,553	(86,413)	190,380
Interest expense	(8)	(150)	(261)	(368)
Interest income	182	783	1,576	1,643
Other (expense) income, net	(937)	287	(545)	9,786
(Loss) income before income taxes	(93,402)	55,473	(85,643)	201,441
Income tax (benefit) provision	(24,221)	5,506	(21,894)	39,401
Net (loss) income	$ (69,181)	$ 49,967	$ (63,749)	$ 162,040
(Loss) earnings per share
Basic (in dollars per share)	$ (0.33)	$ 0.23	$ (0.30)	$ 0.75
Diluted (in dollars per share)	$ (0.33)	0.23	(0.30)	0.75
Dividends per share (in dollars per share)		$ 0.10	$ 0.15	$ 0.30