Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Reconciliation of segment profit to net income attributable to stockholders
Total segments' profit	$ 35,913	$ 31,326	$ 72,264	$ 62,040
General and administrative	(3,992)	(3,866)	(7,757)	(7,052)
Depreciation and amortization	(14,671)	(13,934)	(29,924)	(26,089)
Interest expense	(14,476)	(14,063)	(28,832)	(27,054)
Early extinguishment of debt				(25,867)
Loan transfer and consent fees				(9,019)
Gain on acquisition				46,371
Other income (expense), net	(150)	530	(256)	(71)
Income (loss) from continuing operations	2,624	(7)	5,495	13,259
Discontinued operations
Results from discontinued operations		(462)		(792)
Net income	2,624	455	5,495	14,051
Net income attributable to restricted shares	(131)	(132)	(263)	(218)
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 (Loss) attributable to American Assets Trust, Inc. stockholders	(804)	(104)	(1,687)	225
Net income (loss) attributable to American Assets Trust, Inc. stockholders	$ 1,689	$ 219	$ 3,545	$ (479)