SEGMENTS (Summary of Assets by Segment and Reconciliation of Segment Assets to Total Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Reconciliation of total segment assets to total assets
Assets	$ 7,947,915	$ 7,355,799
Operating Segments
Reconciliation of total segment assets to total assets
Assets	7,498,917	7,017,374
Operating Segments | Operating Assets
Reconciliation of total segment assets to total assets
Assets	2,923,083	2,562,257
Operating Segments | Master Planned Communities
Reconciliation of total segment assets to total assets
Assets	2,204,507	2,076,678
Operating Segments | Seaport District
Reconciliation of total segment assets to total assets
Assets	918,589	839,522
Operating Segments | Strategic Developments
Reconciliation of total segment assets to total assets
Assets	1,452,738	1,538,917
Corporate
Reconciliation of total segment assets to total assets
Assets	$ 448,998	$ 338,425