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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revolving credit facility
Line of Credit Facility [Line Items]
Interest incurred	$ 474	$ 698	$ 1,640	$ 2,452
Capitalized interest	$ 246	$ 264	$ 735	$ 781
Weighted average interest rate	4.60%	2.50%	3.40%	2.20%