SEGMENT REPORTING - Reconciliation of Segment Profit to Net Income Attributable to Stockholders (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting [Abstract]
Total segments’ profit	$ 63,130	$ 55,477
General and administrative	(6,820)	(6,073)
Depreciation and amortization	(27,462)	(20,583)
Interest expense	(13,472)	(13,349)
Other income (expense), net	108	(229)
NET INCOME	15,484	15,243
Net income attributable to restricted shares	(104)	(93)
Net income attributable to unitholders in the Operating Partnership	3,312	4,055
NET INCOME ATTRIBUTABLE TO AMERICAN ASSETS TRUST, INC. STOCKHOLDERS	$ 12,068	$ 11,095