COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive income (loss) - beginning balance	$ 1,995	$ (3,456)	$ (2,357)
Change in fair value of interest rate swaps - cash flow hedges	3,353	5,451	(1,099)
Accumulated other comprehensive income (loss) - ending balance	$ 5,348	$ 1,995	$ (3,456)