Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Trade, allowance for credit losses	$ 90	$ 90
Property, plant and equipment, net	2,541,677	2,493,457
Construction-in-process	905,505	893,198
Operating leases right of use	22,770	23,411
Finance leases right of use	$ 4,277	$ 3,806
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	59,705,941	56,095,918
Common stock, shares outstanding (in shares)	59,705,941	56,095,918
Treasury stock, shares (in shares)	258,667	258,667
Senior Secured Notes [Member]
Deferred financing costs	$ 9,447	$ 10,272
Senior Unsecured Bonds [Member]
Deferred financing costs	3,436	2,995
Convertible Senior Notes [Member]
Deferred financing costs	9,874	10,445
Variable Interest Entity, Primary Beneficiary [Member]
Property, plant and equipment, net	2,424,774	2,326,491
Construction-in-process	366,928	360,508
Operating leases right of use	9,494	9,662
Finance leases right of use	$ 52	$ 75