Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
OPERATING ACTIVITIES
Net income	$ 31,145	$ 22,594	$ 51,601
Results from discontinued operations	0	0	(37,652)
Income from continuing operations	31,145	22,594	13,949
Adjustments to reconcile income from continuing operations to net cash provided by operating activities:
Deferred rent revenue and amortization of lease intangibles	(4,623)	(4,997)	(6,967)
Depreciation and amortization	66,568	66,775	61,853
Amortization of debt issuance costs and debt fair value adjustments	4,075	3,932	3,911
Stock-based compensation expense	3,666	2,845	2,852
Settlement of forward interest rate swap agreement	1,617	0	0
Other noncash interest expense	(39)	0	0
Other, net	(95)	848	2,422
Changes in operating assets and liabilities
Change in restricted cash	1,198	(755)	(1,000)
Change in accounts receivable	279	(45)	63
Change in other assets	(107)	(88)	143
Change in accounts payable and accrued expenses	1,381	1,167	(1,799)
Change in security deposits payable	358	307	(50)
Change in other liabilities and deferred credits	188	151	186
Net cash provided by operating activities of continuing operations	105,611	92,734	75,563
Net cash provided by operating activities of discontinued operations	0	0	382
Net cash provided by operating activities	105,611	92,734	75,945
INVESTING ACTIVITIES
Acquisition of real estate, net of cash acquired	0	0	(273,990)
Capital expenditures	(144,674)	(55,675)	(34,582)
Change in restricted cash, reserves for capital improvements	(3,068)	453	2,557
Leasing commissions	(5,098)	(3,032)	(3,456)
Maturity of marketable securities	0	0	4,384
Sale of marketable securities	0	0	23,191
Net cash used in investing activities of continuing operations	(152,840)	(58,254)	(281,896)
Net cash provided by investing activities of discontinued operations	0	0	87,601
Net cash used in investing activities	(152,840)	(58,254)	(194,295)
FINANCING ACTIVITIES
Change in restricted cash	0	(1,400)	0
Issuance of secured notes payable	0	0	132,900
Repayment of secured notes payable	(142,276)	(95,420)	(34,626)
Proceeds from term loan	100,000	0	0
Proceeds from unsecured line of credit	0	93,000	164,000
Repayment of unsecured line of credit	93,000	0	164,000
Proceeds from issuance of senior guaranteed notes payable	150,000	0	0
Debt issuance costs	(2,141)	0	(1,355)
Proceeds from issuance of common stock, net	104,107	25,348	0
Dividends paid to common stock and unitholders	(54,311)	(49,500)	(48,452)
Deferred offering costs	0	0	(361)
Shares withheld for employee taxes	(4,780)	0	0
Net cash provided by (used in) financing activities	57,599	(27,972)	48,106
Net (decrease) increase in cash and cash equivalents	10,370	6,508	(70,244)
Cash and cash equivalents, beginning of period	48,987	42,479	112,723
Cash and cash equivalents, end of period	59,357	48,987	42,479
American Assets Trust, L.P.
OPERATING ACTIVITIES
Net income	31,145	22,594	51,601
Results from discontinued operations	0	0	(37,652)
Income from continuing operations	31,145	22,594	13,949
Adjustments to reconcile income from continuing operations to net cash provided by operating activities:
Deferred rent revenue and amortization of lease intangibles	(4,623)	(4,997)	(6,967)
Depreciation and amortization	66,568	66,775	61,853
Amortization of debt issuance costs and debt fair value adjustments	4,075	3,932	3,911
Stock-based compensation expense	3,666	2,845	2,852
Settlement of forward interest rate swap agreement	1,617	0	0
Other noncash interest expense	(39)	0	0
Other, net	(95)	848	2,422
Changes in operating assets and liabilities
Change in restricted cash	1,198	(755)	(1,000)
Change in accounts receivable	279	(45)	63
Change in other assets	(107)	(88)	143
Change in accounts payable and accrued expenses	1,381	1,167	(1,799)
Change in security deposits payable	358	307	(50)
Change in other liabilities and deferred credits	188	151	186
Net cash provided by operating activities of continuing operations	105,611	92,734	75,563
Net cash provided by operating activities of discontinued operations	0	0	382
Net cash provided by operating activities	105,611	92,734	75,945
INVESTING ACTIVITIES
Acquisition of real estate, net of cash acquired	0	0	(273,990)
Capital expenditures	(144,674)	(55,675)	(34,582)
Change in restricted cash, reserves for capital improvements	(3,068)	453	2,557
Leasing commissions	(5,098)	(3,032)	(3,456)
Maturity of marketable securities	0	0	4,384
Sale of marketable securities	0	0	23,191
Net cash used in investing activities of continuing operations	(152,840)	(58,254)	(281,896)
Net cash provided by investing activities of discontinued operations	0	0	87,601
Net cash used in investing activities	(152,840)	(58,254)	(194,295)
FINANCING ACTIVITIES
Change in restricted cash	0	(1,400)	0
Issuance of secured notes payable	0	0	132,900
Repayment of secured notes payable	(142,276)	(95,420)	(34,626)
Proceeds from term loan	100,000	0	0
Proceeds from unsecured line of credit	0	93,000	164,000
Repayment of unsecured line of credit	93,000	0	164,000
Proceeds from issuance of senior guaranteed notes payable	150,000	0	0
Debt issuance costs	(2,141)	0	(1,355)
Proceeds from issuance of common stock, net	104,107	25,348	0
Dividends paid to common stock and unitholders	(54,311)	(49,500)	(48,452)
Deferred offering costs	0	0	(361)
Shares withheld for employee taxes	(4,780)	0	0
Net cash provided by (used in) financing activities	57,599	(27,972)	48,106
Net (decrease) increase in cash and cash equivalents	10,370	6,508	(70,244)
Cash and cash equivalents, beginning of period	48,987	42,479	112,723
Cash and cash equivalents, end of period	$ 59,357	$ 48,987	$ 42,479