Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property, plant and equipment, net	$ 1,621,012	$ 1,556,378
Construction-in-process	$ 350,872	$ 306,709
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)	50,597,124	49,667,340
Common stock, shares outstanding (in shares)	50,597,124	49,667,340
Senior Secured Notes [Member]
Deferred financing costs	$ 8,202	$ 9,177
Other Loans, Limited and Non-recourse [Member]
Deferred financing costs	5,496	6,409
Senior Unsecured Bonds [Member]
Deferred financing costs	617	755
Other Loans, Full Recourse [Member]
Deferred financing costs	1,043	1,346
Variable Interest Entity, Primary Beneficiary [Member]
Property, plant and equipment, net	1,518,962	1,483,224
Construction-in-process	$ 105,848	$ 120,853