BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 205,577	$ 35,470
Short-term investments	17,501	17,501
Trade accounts receivable	138,399	117,746
Other receivables	1,434	5,306
Income tax receivable	21,607	9,176
Inventories, net	56,719	54,294
Prepaid expenses and other	27,932	29,376
Total current assets	469,169	268,869
Mineral interests, net	120,427	130,004
Property, plant and equipment, net	540,315	536,745
Non-current income tax receivable	21,310	39,255
Deferred income taxes	222,780	0
Other long-term assets	21,039	18,442
Total assets	1,395,040	993,315
Current liabilities:
Accounts payable	33,588	28,076
Accrued expenses	82,342	66,704
Asset retirement obligations	2,775	3,572
Other current liabilities	4,967	6,903
Current portion of long-term debt	760	2,965
Total current liabilities	124,432	108,220
Total long-term debt	468,231	342,948
Deferred income taxes	0	258
Asset retirement obligations	59,049	96,096
Black lung obligations	25,206	30,208
Other long-term liabilities	5,510	2,562
Total liabilities	682,428	580,292
Commitments and contingencies
Stockholders’ Equity:
Common stock, $0.01 par value per share (Authorized -140,000,000 shares, 53,256,098 issued and 51,622,898 outstanding as of December 31, 2018 and 53,284,470 issued and outstanding as of December 31, 2017)	533	534
Preferred stock, $0.01 par value per share (10,000,000 shares authorized, no shares issued and outstanding)	0	0
Treasury Stock, at cost (1,633,200 shares)	(38,030)	0
Additional paid in capital	239,827	329,993
Retained earnings	510,282	82,496
Total stockholders’ equity	712,612	413,023
Total liabilities and stockholders’ equity	$ 1,395,040	$ 993,315