SEGMENT REPORTING - Reconciliation of Segment Profit to Net Income Attributable to Stockholders (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting [Abstract]
Total segments’ profit	$ 54,386	$ 63,130
General and administrative	(6,823)	(6,820)
Depreciation and amortization	(27,501)	(27,462)
Interest expense	(14,005)	(13,472)
Early extinguishment of debt	(4,271)	0
Other (expense) income, net	(53)	108
NET INCOME	1,733	15,484
Net income attributable to restricted shares	(137)	(104)
Net income attributable to unitholders in the Operating Partnership	339	3,312
NET INCOME ATTRIBUTABLE TO AMERICAN ASSETS TRUST, INC. STOCKHOLDERS	$ 1,257	$ 12,068