NON-CONTROLLING INTEREST IN OPERATING PARTNERSHIP NON-CONTROLLING INTEREST IN OPERATING PARTNERSHIP - Activity (Details) - USD ($) $ in Thousands	2 Months Ended	3 Months Ended
	Dec. 31, 2015	Mar. 31, 2016
Increase (Decrease) in Temporary Equity [Roll Forward]
Non-controlling interest, beginning of period		$ 140,953
Non-controlling interest, end of period	$ 140,953	141,965
Westfield U.S. Holdings, LLC
Increase (Decrease) in Temporary Equity [Roll Forward]
Non-controlling interest, beginning of period	0	140,953
Issuance of Series A Preferred Units	140,000
Preferred distribution accrual	953	1,750
Payment of distribution		(738)
Non-controlling interest, end of period	$ 140,953	$ 141,965