COMMITMENTS AND CONTINGENCIES Springfield Town Center Acquisition (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Significant Pending Acquisition [Line Items]
Present value of additional consideration	$ 0		$ 8,600,000
Project costs and other expenses	$ (768,000)	$ (1,700,000)	$ (6,108,000)