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, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revolving credit facility
Line of Credit Facility [Line Items]
Interest incurred	$ 655	$ 474	$ 1,541	$ 1,640
Capitalized interest	$ 180	$ 246	$ 392	$ 735
Weighted average interest rate	2.10%	4.60%	2.50%	3.40%