Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
REVENUE:
Rental income	$ 225,249	$ 194,168	$ 115,165
Other property income	10,217	8,617	2,583
Total revenue	235,466	202,785	117,748
EXPENSES:
Rental expenses	64,089	58,133	20,520
Real estate taxes	22,025	18,746	11,688
General and administrative	15,593	13,627	8,699
Depreciation and amortization	61,853	55,936	34,419
Total expenses	163,560	146,442	75,326
Operating income (loss)	71,906	56,343	42,422
Interest expense	(57,328)	(54,580)	(43,251)
Early extinguishment of debt		(25,867)
Loan transfer and consent fees		(8,808)
Gain on acquisition		46,371	4,297
Other income (expense), net	(629)	212	(1,846)
INCOME FROM CONTINUING OPERATIONS	13,949	13,671	1,622
Discontinued operations
Income from discontinued operations	932	1,672	552
Gain on sale of real estate property	36,720	3,981
Results from discontinued operations	37,652	5,653	552
NET INCOME	51,601	19,324	2,174
Net income attributable to restricted shares	(529)	(482)
Net loss attributable to Predecessor's noncontrolling interests in consolidated real estate entities		2,458	2,205
Net income attributable to Predecessor's controlled owners' equity		(16,995)	(4,379)
Net income attributable to unitholders in the Operating Partnership	(16,133)	(1,388)
NET INCOME ATTRIBUTABLE TO AMERICAN ASSETS TRUST, INC. STOCKHOLDERS	$ 34,939	$ 2,917
EARNINGS PER COMMON SHARE, BASIC
Continuing operations	$ 0.24	$ (0.02)
Discontinued operations	$ 0.66	$ 0.10
Basic net income attributable to common stockholders per share	$ 0.90	$ 0.08
Weighted average shares of common stock outstanding-basic	38,736,113	36,748,806
EARNINGS PER COMMON SHARE, DILUTED
Continuing operations	$ 0.24	$ (0.02)
Discontinued operations	$ 0.66	$ 0.10
Diluted net income attributable to common stockholders per share	$ 0.90	$ 0.08
Weighted average shares of common stock outstanding-diluted	57,053,909	54,219,807