EQUITY OF AMERICAN ASSETS TRUST, INC. - ATM Equity Program (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015
Equity [Line Items]
Proceeds from issuance of common stock	$ 9,665	$ 9,665	$ 72,836
At The Market Equity Program
Equity [Line Items]
Common shares issued (in shares)	219,480	219,480
Weighted average price per share	$ 45.50	$ 45.50
Proceeds, gross	$ 9,986	$ 9,986
At The Market Equity Program | Sales agent compensation
Equity [Line Items]
Sales agent compensation and offering costs	(100)	(100)
At The Market Equity Program | Offering costs
Equity [Line Items]
Sales agent compensation and offering costs	$ (221)	$ (221)