SEGMENT REPORTING Reconciliation of Segment Profit to Net Income Attributable to Stockholders (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting [Abstract]
Total Segments' profit	$ 44,070	$ 42,120	$ 125,974	$ 123,966
General and administrative	(4,682)	(4,031)	(13,929)	(12,658)
Depreciation and amortization	(16,352)	(16,648)	(50,902)	(50,614)
Interest expense	13,325	14,764	40,396	44,244
Other income (expense), net	(621)	(419)	352	(763)
NET INCOME	9,090	6,258	21,099	15,687
Net income attributable to restricted shares	(95)	(132)	(259)	(397)
Net income attributable to unitholders in the Operating Partnership	2,578	1,903	6,108	4,752
NET INCOME ATTRIBUTABLE TO AMERICAN ASSETS TRUST, INC. STOCKHOLDERS	$ 6,417	$ 4,223	$ 14,732	$ 10,538