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		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revolving credit facility
Line of Credit Facility [Line Items]
Interest incurred	$ 472	$ 324	$ 886	$ 677
Capitalized interest	$ 115	$ 247	$ 212	$ 489
Weighted average interest rate	2.67%	3.12%	2.97%	3.05%