Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Reconciliation of segment profit to net income attributable to stockholders
Total segments' profit	$ 39,511	$ 34,716	$ 111,775	$ 96,756
General and administrative	(3,959)	(3,733)	(11,716)	(10,786)
Depreciation and amortization	(16,432)	(15,827)	(46,356)	(41,916)
Interest expense	(14,690)	(14,738)	(43,522)	(41,791)
Early extinguishment of debt				(25,867)
Loan transfer and consent fees				(9,019)
Gain on acquisition				46,371
Other income (expense), net	68	(108)	(188)	(179)
INCOME FROM CONTINUING OPERATIONS	4,498	310	9,993	13,569
Discontinued operations
Results from discontinued operations	(213)	4,308	(213)	5,100
NET INCOME	4,285	4,618	9,780	18,669
Net income attributable to restricted shares	(133)	(132)	(396)	(350)
Net loss attributable to Predecessor's noncontrolling interests in consolidated real estate entities				2,458
Net income attributable to Predecessor's controlled owners' equity				(16,995)
Net income attributable to unitholders in the Operating Partnership	(1,335)	(1,434)	(3,022)	(1,209)
Net income attributable to American Assets Trust, Inc. stockholders	$ 2,817	$ 3,052	$ 6,362	$ 2,573