CONDENSED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Total revenues	$ 226,720	$ 378,290
Costs and expenses:
Cost of sales (exclusive of items shown separately below)	151,514	182,628
Cost of other revenues (exclusive of items shown separately below)	7,561	7,745
Depreciation and depletion	28,692	22,233
Selling, general and administrative	8,456	8,905
Total costs and expenses	196,223	221,511
Operating income	30,497	156,779
Interest expense, net	(7,533)	(8,592)
Loss on early extinguishment of debt	0	(9,756)
Other income	1,822	0
Income before income tax expense	24,786	138,431
Income tax expense	3,241	27,984
Net income	$ 21,545	$ 110,447
Basic and diluted net income per share:
Net income per share—basic (in dollars per share)	$ 0.42	$ 2.14
Net income per share—diluted (in dollars per share)	$ 0.42	$ 2.14
Weighted average number of shares outstanding—basic (in shares)	51,106	51,511
Weighted average number of shares outstanding—diluted (in shares)	51,273	51,630
Dividends per share (in dollars per share)	$ 0.05	$ 0.05
Sales
Revenues:
Total revenues	$ 221,338	$ 369,681
Other revenues
Revenues:
Total revenues	$ 5,382	$ 8,609