Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Assets
Operating real estate	$ 1,659,106	$ 1,117,831
Construction in progress	3,495	925
Held for development	24,675	8,081
Total Real estate, at cost	1,687,276	1,126,837
Accumulated depreciation	(234,595)	(209,666)
Net real estate	1,452,681	917,171
Cash and cash equivalents	112,723	41,953
Restricted cash	9,216	4,481
Marketable securities	28,235
Accounts receivable, net	6,847	1,564
Deferred rent receivables, net	23,294	19,486
Notes receivable from affiliate		21,769
Investment in real estate joint ventures		39,816
Prepaid expenses and other assets	76,285	43,718
Assets of discontinued operations		27,399
Total assets	1,709,281	1,117,357
Liabilities and equity
Secured notes payable	943,479	828,685
Unsecured notes payable		38,013
Notes payable to affiliates		5,266
Accounts payable and accrued expenses	25,476	11,284
Security deposits payable	4,790	2,510
Other liabilities and deferred credits	55,808	38,846
Distributions in excess of earnings on real estate joint ventures		14,060
Liabilities of discontinued operations		23,572
Total liabilities	1,029,553	962,236
Commitments and contingencies (Note 12)
Equity:
Owners' equity		121,874
American Assets Trust, Inc. stockholders' equity
Common stock $0.01 par value, 490,000,000 shares authorized, 39,283,796 shares outstanding at December 31, 2011	393
Additional paid-in capital	653,645
Accumulated dividends in excess of net income	(28,007)
Total American Assets Trust, Inc. stockholders' equity	626,031
Noncontrolling interests
Owners in consolidated real estate entities		33,247
Unitholders in the Operating Partnership	53,697
Total Noncontrolling interests	53,697	33,247
Total equity	679,728	155,121
Total liabilities and equity	$ 1,709,281	$ 1,117,357