EQUITY OF AMERICAN ASSETS TRUST, INC. (Details)			3 Months Ended		9 Months Ended
	Jun. 14, 2016 shares	May 27, 2015 USD ($) Agent	Sep. 30, 2016 USD ($) shares	Sep. 30, 2015 USD ($) shares	Sep. 30, 2016 USD ($) shares	Sep. 30, 2015 USD ($) shares
Equity [Line Items]
Noncash compensation expense			$ 600,000	$ 400,000	$ 1,900,000	$ 2,100,000
Unrecognized compensation expense			$ 1,800,000		$ 1,800,000
Weighted average unvested shares outstanding (in shares) | shares			169,963	168,529	171,760	196,927
Restricted Stock Units (RSUs)
Equity [Line Items]
Granted, Shares | shares	4,900				4,900
At The Market Equity Program
Equity [Line Items]
Number of sales agents | Agent		5
Aggregate offering price of common share		$ 250,000,000.0
Remaining capacity to issue			$ 206,600,000		$ 206,600,000