Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
CURRENT ASSETS:
Cash and cash equivalents	$ 244,048	$ 132,735
Short-term investments	114,437	0
Accounts receivable, net of allowance for doubtful accounts	51,889	57,572
Inventories, net	65,269	58,290
Prepaid expenses	8,182	9,778
Other current assets	3,315	3,590
Total Current Assets	487,140	261,965
Property, plant and equipment, net	865,237	800,586
Deposits on equipment	2,429	3,823
Operating lease right of use assets	4,358	5,165
Equity method investment	0	25,418
Long term investment in equity securities	23,528	0
Other assets	27,679	28,426
Total Assets	1,410,371	1,125,383
CURRENT LIABILITIES:
Accounts payable	32,389	55,088
Accrued expenses	43,477	33,016
Current operating lease liabilities	1,576	1,510
Total Current Liabilities	77,442	89,614
Convertible senior notes	392,048	0
Long term operating lease liabilities	3,097	4,200
Total Liabilities	472,587	93,814
Commitments and contingencies
STOCKHOLDERS' EQUITY:
Common stock — voting, $0.001 par value, 200,000 shares authorized, 48,199 issued and 48,185 outstanding on June 30, 2023, and 48,051 issued and 48,037 outstanding on December 31, 2022	48	48
Additional paid-in capital	1,275,510	1,325,524
Accumulated deficit	(336,855)	(295,117)
Accumulated other comprehensive (loss) income	(663)	1,370
Treasury stock, at cost — 14 shares on June 30, 2023 and on December 31, 2022	(256)	(256)
Total Stockholders' Equity	937,784	1,031,569
Total Liabilities and Stockholders' Equity	$ 1,410,371	$ 1,125,383