COMMITMENTS AND CONTINGENCIES Springfield Town Center Acquisition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Significant Pending Acquisition [Line Items]
Acquisition costs and other expenses	$ (1,700)	$ (6,108)	$ (4,937)