NOTES PAYABLE TO BANKS - Interest incurred on credit facility, interest capitalized related to facilities and equipment under construction, and related weighted average interest rates (Details) - Revolving credit facility - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Line of Credit Facility [Line Items]
Interest incurred	$ 115	$ 376	$ 334	$ 1,738
Capitalized interest		$ 145		$ 455
Weighted average interest rate		4.30%		2.10%