Alexandria Real Estate Equities (ARE) 10-K 24 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 13, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	ALEXANDRIA REAL ESTATE EQUITIES INC
Entity Central Index Key	1035443
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$5.50
Entity Common Stock, Shares Outstanding		72,033,942
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets
Investments in real estate	$7,226,016	$6,776,914
Cash and cash equivalents	86,011	57,696
Restricted cash	26,884	27,709
Tenant receivables	10,548	9,918
Deferred rent	234,124	190,425
Deferred leasing and financing costs	201,798	192,658
Investments	236,389	140,288
Other assets	114,266	134,156
Total assets	8,136,036	7,529,764
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	652,209	708,831
Unsecured senior notes payable	1,747,370	1,048,230
Unsecured senior line of credit	304,000	204,000
Unsecured senior bank term loans	975,000	1,100,000
Accounts payable, accrued expenses, and tenant security deposits	489,085	435,342
Dividends payable	58,814	54,420
Total liabilities	4,226,478	3,550,823
Commitments and contingencies
Redeemable noncontrolling interests	14,315	14,444
Alexandria Real Estate Equities, Inc.’s stockholders’ equity:
7.00% Series D cumulative convertible preferred stock, $0.01 par value per share, 10,000,000 shares authorized; 9,486,500 and 10,000,000 shares issued and outstanding as of December 31, 2014 and 2013, respectively; $25 liquidation value per share	237,163	250,000
6.45% Series E cumulative redeemable preferred stock, $0.01 par value per share, 5,200,000 shares authorized, issued, and outstanding as of December 31, 2014 and 2013; $25 liquidation value per share	130,000	130,000
Common stock, $0.01 par value per share, 100,000,000 shares authorized; 71,463,876 and 71,172,197 issued and outstanding as of December 31, 2014 and 2013, respectively	715	712
Additional paid-in capital	3,461,189	3,572,281
Accumulated other comprehensive loss	-628	-36,204
Alexandria’s stockholders’ equity	3,828,439	3,916,789
Noncontrolling interests	66,804	47,708
Total equity	3,895,243	3,964,497
Total liabilities, noncontrolling interests, and equity	$8,136,036	$7,529,764

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Preferred stock, shares authorized	100,000,000
Preferred Stock, Shares Issued	14,700,000
Common Stock, Par or Stated Value Per Share	$0.01	$0.01
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Shares, Issued	71,463,876	71,172,197
Common Stock, Shares, Outstanding	71,463,876	71,172,197
Series D Convertible Preferred Stock
Percentage of dividend on preferred stock	7.00%	7.00%
Preferred Stock, Par or Stated Value Per Share	$0.01	$0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	9,486,500	10,000,000
Series D Preferred Stock, Shares Outstanding	9,486,500	10,000,000
Preferred Stock, Liquidation Preference Per Share	$25	$25
Series E Cumulative Redeemable Preferred Stock
Percentage of dividend on preferred stock	6.45%	6.45%
Preferred Stock, Par or Stated Value Per Share	$0.01	$0.01
Preferred stock, shares authorized	5,200,000	5,200,000
Preferred Stock, Shares Issued	5,200,000	5,200,000
Series D Preferred Stock, Shares Outstanding	5,200,000	5,200,000
Preferred Stock, Liquidation Preference Per Share	$25	$25

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended																12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues:
Rental																	$544,153		$467,764		$422,793
Tenant recoveries																	173,480		150,095		133,280
Other Income																	9,244		13,292		18,424
Total revenues	188,674		185,615		176,402		176,186		168,823		158,315		153,930		150,083		726,877		631,151		574,497
Expenses:
Rental operations																	219,164		189,039		172,756
General and administrative																	53,530		48,520		47,747
Interest																	79,299		67,952	[1]	69,184	[1]
Depreciation and amortization																	224,096		189,123		185,687
Impairment of real estate																	51,675		0		2,050
Loss on early extinguishment of debt																	525		1,992		2,225
Total expenses																	628,289		496,626		479,649
Equity in earnings of unconsolidated joint ventures																	554		0		0
Income from continuing operations																	99,142		134,525		94,848
Income from discontinued operations																	1,233	[2]	900	[2]	8,816	[2]
Gain on sales of real estate - land parcels																	6,403		4,824		1,864
Net income																	106,778		140,249		105,528
Dividends on preferred stock																	-25,698		-25,885		-27,328
Preferred stock redemption charge																	1,989		0		5,978
Net income attributable to noncontrolling interests																	-5,204		-4,032		-3,402
Net income attributable to unvested restricted stock awards																	-1,774		-1,581		-1,190
Net Income attributable to Alexandria's common stockholders	($16,154)		$27,626		$27,932		$32,709		$36,247		$24,579		$25,483		$22,442		$72,113		$108,751		$67,630
Earnings per share attributable to Alexandria’s common stockholders – basic and diluted:
Continuing operations																	$0.99		$1.59		$0.95
Discontinued operations																	$0.02		$0.01		$0.14
Earnings per share – basic and diluted	($0.23)	[3],[4]	$0.39	[3]	$0.39	[3]	$0.46	[3]	$0.51	[3]	$0.35	[3]	$0.38	[3]	$0.36	[3]	$1.01		$1.60		$1.09
[1]	Includes interest expense related to and classified in income from discontinued operations in the accompanying consolidated statements of income.
[2]	Income from discontinued operations includes the results of operations of three properties that were disposed of during the year ended December 31, 2014, and the results of one property which was classified as “held for sale” prior to adoption of the new ASU and included as discontinued operations as of December 31, 2014, as well as the results of operations (prior to disposition) and gain (loss) on sale of real estate attributable to 16 properties sold during the period from January 1, 2012, to December 31, 2014.
[3]	(1)Quarterly earnings per common share amounts may not total to the annual amounts due to rounding and due to the increase in the weighted average shares of common stock outstanding.
[4]	(2)Results for the fourth quarter of 2014 include an aggregate net loss of $46.2 million, or $0.65 per share, related to impairments of real estate and a preferred stock redemption charge, partially offset by gains on sales of real estate. See further discussion of impairments of real estate and gains on real estate in Note 3 – “Investments in Real Estate.

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$106,778	$140,249	$105,528
Unrealized gains (losses) on marketable securities:
Unrealized holding gains arising during the year	51,135	1,300	990
Reclassification adjustment for gains included in net income	-358	-1,183	-3,351
Unrealized gains (losses) on marketable securities, net	50,777	117	-2,361
Unrealized gains on interest rate swaps:
Unrealized interest rate swap (losses) gains arising during the year	-4,459	1,918	-9,990
Reclassification adjustment for amortization of interest expense included in net income	6,871	15,422	22,309
Unrealized gains on interest rate swap agreements, net	2,412	17,340	12,319
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]
Unrealized foreign currency translation losses during the year	-18,075	-28,912	-318
Reclassification adjustment for gains included in net income	-208	0	0
Unrealized losses on foreign currency translation, net	-18,283	-28,912	-318
Total other comprehensive income (loss)	34,906	-11,455	9,640
Comprehensive income	141,684	128,794	115,168
Less: comprehensive income attributable to noncontrolling interests	-4,534	-3,948	-3,364
Comprehensive income attributable to Alexandria’s common stockholders	$137,150	$124,846	$111,804

Consolidated_Statement_of_Chan

Consolidated Statement of Changes in Stockholders' Equity and Noncontrolling Interests (USD $)	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests	Redeemable Noncontrolling Interests [Member]	Series C Preferred Stock	Series C Preferred Stock	Series C Preferred Stock	Series C Preferred Stock	Series D Convertible Preferred Stock	Series D Convertible Preferred Stock	Series D Convertible Preferred Stock	Series D Convertible Preferred Stock	Series E Cumulative Redeemable Preferred Stock	Series E Cumulative Redeemable Preferred Stock	Series E Cumulative Redeemable Preferred Stock
In Thousands, except Share data, unless otherwise specified									Preferred Stock	Additional Paid-In Capital	Retained Earnings		Preferred Stock	Additional Paid-In Capital	Retained Earnings		Preferred Stock	Additional Paid-In Capital
Beginning balance at Dec. 31, 2011							$16,034
Beginning balance at Dec. 31, 2011	3,416,859	616	3,028,558	0	-34,511	42,558			129,638				250,000				0
Beginning balance, common shares at Dec. 31, 2011		61,560,472
Increase (Decrease) in Stockholders' Equity
Net Income	104,555			102,126		2,429
Total other comprehensive loss	9,690				9,678	12
Contributions by noncontrolling interests	1,875					1,875
Distributions to noncontrolling interests	-913					-913
Redemption and conversion of noncontrolling interests	694		12			682
Issuance of common stock (in shares)		1,366,977
Issuance of stock	97,890	14	97,876													124,868	130,000	-5,132
Issuances pursuant to stock plan (in shares)		317,196
Issuances pursuant to stock plan	22,082	2	22,080
Redemption of Series C Preferred Stock								-129,638	-129,638	5,978	-5,978
Dividends declared on common stock	-131,790			-131,790
Dividends declared on preferred stock	-27,678			-27,678
Distributions in excess of earnings			63,320	-63,320
Increase (Decrease) in Temporary Equity [Roll Forward]
Net Income							973
Total other comprehensive income (loss)							-50
Distributions to noncontrolling interests							-1,249
Redemption of and conversion of noncontrolling interests							-1,144
Ending balance at Dec. 31, 2012							14,564
Ending balance at Dec. 31, 2012	3,488,494	632	3,086,052	0	-24,833	46,643			0				250,000				130,000
Ending balance, common shares at Dec. 31, 2012		63,244,645
Increase (Decrease) in Stockholders' Equity
Net Income	139,178			136,217		2,961
Total other comprehensive loss	-11,455				-11,371	-84
Distributions to noncontrolling interests	-1,812					-1,812
Issuance of common stock (in shares)		7,590,000
Issuance of stock	534,469	76	534,393
Issuances pursuant to stock plan (in shares)		337,552
Issuances pursuant to stock plan	23,612	4	23,608
Dividends declared on common stock	-182,104			-182,104
Dividends declared on preferred stock	-25,885			-25,885
Distributions in excess of earnings			71,772	-71,772
Increase (Decrease) in Temporary Equity [Roll Forward]
Net Income							1,071
Total other comprehensive income (loss)							0
Distributions to noncontrolling interests							1,191
Ending balance at Dec. 31, 2013	14,444						14,444
Ending balance at Dec. 31, 2013	3,964,497	712	3,572,281	0	-36,204	47,708			0				250,000				130,000
Ending balance, common shares at Dec. 31, 2013	71,172,197	71,172,197
Increase (Decrease) in Stockholders' Equity
Net Income	105,716			101,574		4,142
Total other comprehensive loss	34,906				35,576	-670
Contributions by noncontrolling interests	19,410					19,410
Distributions to noncontrolling interests	-3,786					-3,786
Issuances pursuant to stock plan (in shares)		291,679
Issuances pursuant to stock plan	21,579	3	21,576
Redemption of Series C Preferred Stock												-14,414	-12,837	412	-1,989
Dividends declared on common stock	-206,967			-206,967
Dividends declared on preferred stock	-25,698			-25,698
Distributions in excess of earnings			-133,080	133,080
Increase (Decrease) in Temporary Equity [Roll Forward]
Net Income							1,062
Total other comprehensive income (loss)							0
Distributions to noncontrolling interests							-1,191
Ending balance at Dec. 31, 2014	14,315						14,315
Ending balance at Dec. 31, 2014	$3,895,243	$715	$3,461,189	$0	($628)	$66,804			$0				$237,163				$130,000
Ending balance, common shares at Dec. 31, 2014	71,463,876	71,463,876

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities
Net income	$106,778	$140,249	$105,528
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and Amortization	224,096	190,778	192,005
Loss on early extinguishment of debt	525	1,992	2,225
(Gain) loss on sale of real estate	-1,838	121	-1,564
Impairment of real estate	51,675	0	13,450
Gain on sales of real estate - land parcels	-6,403	-4,824	-1,864
Equity in earnings of unconsolidated joint ventures	-554	0	0
Distributions of earnings from unconsolidated joint ventures	549	0	0
Amortization of loan fees and costs	10,909	9,936	9,832
Amortization of debt premiums/discounts	117	529	511
Amortization of acquired above and below market leases	-2,845	-3,316	-3,200
Deferred rent	-44,726	-27,935	-28,456
Stock compensation expense	13,996	15,552	14,160
Investment gains	-11,613	-7,050	-15,018
Investment losses	9,287	1,480	2,637
Changes in operating assets and liabilities:
Restricted cash	4,141	899	-261
Tenant receivables	-673	-1,519	-981
Deferred leasing costs	-38,282	-54,825	-45,099
Other assets	-7,466	-6,298	-4,069
Accounts payable, accrued expenses, and tenant security deposits	26,652	56,958	65,697
Net cash provided by operating activities	334,325	312,727	305,533
Investing Activities
Proceeds from sales of real estate	81,580	153,968	36,179
Additions to real estate	-497,773	-593,389	-549,030
Purchase of real estate	-127,887	-122,069	-42,171
Deposits for investing activities	-10,282	0	0
Change in restricted cash related to construction projects	1,665	7,655	-9,377
Investment in unconsolidated joint venture	-70,758	-17,987	-6,700
Distribution from unconsolidated joint venture	0	0	22,250
Additions to investments	-60,230	-36,078	-36,294
Proceeds from sales of investments	18,973	16,525	27,043
Proceeds from repayment of notes receivable	29,883	0	0
Net Cash Provided by (Used in) Investing Activities	-634,829	-591,375	-558,100
Financing Activities
Borrowings from secured notes payable	126,215	28,489	17,810
Repayments of borrowings from secured notes payable	-231,051	-36,219	-26,367
Proceeds from issuance of unsecured senior notes payable	698,908	498,561	544,650
Principal borrowings from unsecured senior line of credit and unsecured senior bank term loans	1,168,000	729,000	847,147
Repayments of borrowings from unsecured senior line of credit	-1,068,000	-1,091,000	-651,147
Repayment of unsecured senior bank term loan	-125,000	-250,000	-250,000
Repurchase of unsecured senior convertible notes	0	-384	-84,801
Redemption of Series C Cumulative Redeemable Preferred Stock	0	0	-129,638
Redemption of Series D Cumulative Convertible Preferred Stock	-14,414	0	0
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock	0	0	124,868
Change in restricted cash related to financings	-1,409	2,546	-7,428
Loan fees and costs paid	-8,099	-19,928	-13,225
Proceeds from common stock offerings	0	534,469	97,890
Proceeds from exercise of stock options	0	0	155
Dividends paid on common stock	-202,386	-169,076	-126,498
Dividends paid on preferred stock	-25,885	-25,885	-27,819
Distributions to redeemable noncontrolling interests	-1,191	-1,191	-1,249
Redemption of redeemable noncontrolling interests	0	0	-450
Contributions by noncontrolling interests	19,410	0	1,875
Distributions to noncontrolling interests	-3,786	-1,812	-913
Net cash provided by financing activities	331,312	197,570	314,860
Effect of foreign exchange rate changes on cash and cash equivalents	-2,493	-2,197	139
Net (decrease) increase in cash and cash equivalents	28,315	-83,275	62,432
Cash and cash equivalents at beginning of period	57,696	140,971	78,539
Cash and cash equivalents at end of period	86,011	57,696	140,971
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	57,966	59,857	52,561
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	2,000	38,820	6,125
Write-off of fully amortized improvements	0	0	-17,730
Change in accrued capital expenditures	29,846	-21,310	46,087
Assumption of secured notes payable in connection with purchase of properties	($48,329)	$0	$0

Background_Notes

Background (Notes)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background	Background
	As used in this annual report on Form 10-K, references to the “Company,” “Alexandria,” “we,” “our,” and “us” refer to Alexandria Real Estate Equities, Inc. and its subsidiaries.
	Alexandria Real Estate Equities, Inc. (NYSE:ARE), is a self-administered and self-managed investment-grade REIT, and is the largest and leading REIT uniquely focused on collaborative science campuses in urban innovation clusters, with a total market capitalization of $10.4 billion as of December 31, 2014, and an asset base of 31.5 million square feet, including 18.7 million RSF of operating and current value-creation projects, as well as an additional 12.8 million square feet in future ground-up development projects. Alexandria pioneered this niche in 1994 and has since established a dominant market presence in AAA locations, including Greater Boston, the San Francisco Bay Area, New York City, San Diego, Seattle, Maryland, and Research Triangle Park. Alexandria is known for its high-quality and diverse client tenant base, with approximately 56% of its total ABR results from investment-grade client tenants. Alexandria has a longstanding and proven track record of developing Class A assets clustered in urban campuses that provide its innovative client tenants with highly dynamic and collaborative ecosystems that enhance their ability to successfully recruit and retain world-class talent and inspire productivity, efficiency, creativity, and success. We believe these advantages result in higher occupancy levels, longer lease terms, higher rental income, higher returns, and greater long-term asset value. For additional information on Alexandria, please visit www.are.com.
	Our asset base consisted of the following, as of December 31, 2014:
			Square Feet
			(unaudited)
	Operating properties		16,727,985
	Development properties (includes unconsolidated JVs)		1,857,520
	Redevelopment properties		143,777
	Total operating and current value-creation projects		18,729,282
	Near-term value-creation projects in North America (CIP)		2,715,792
	Future value-creation projects		10,093,396
			12,809,188
	Total		31,538,470
	As of December 31, 2014, we had 562 leases with a total of 441 client tenants, and 87, or 45%, of our 193 properties were single-tenant properties. Leases in our multi-tenant buildings typically have terms of five to 10 years, while the single-tenant building leases typically have terms of 10 to 20 years. As of December 31, 2014:
	•	Investment-grade client tenants represented 56% of our total ABR;
	•	Approximately 95% of our leases (on an RSF basis) were triple net leases, requiring client tenants to pay substantially all real estate taxes, insurance, utilities, common area, and other operating expenses (including increases thereto) in addition to base rent;
	•	Approximately 94% of our leases (on an RSF basis) contained effective annual rent escalations that were either fixed (generally ranging from 3% to 3.5%) or indexed based on a consumer price index or other index; and
	•	Approximately 93% of our leases (on an RSF basis) provided for the recapture of certain capital expenditures (such as HVAC systems maintenance and/or replacement, roof replacement, and parking lot resurfacing) that we believe would typically be borne by the landlord in traditional office leases.
	Any references to the number of buildings, square footage, number of leases, occupancy, and client tenants, and any amounts derived from these values in the notes to consolidated financial statements are unaudited.

Basis_of_presentation_and_summ

Basis of presentation and summary of significant accounting policies (Notes)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of presentation and summary of significant accounting policies	Basis of presentation and summary of significant accounting policies
	Recent accounting pronouncements
	In April 2014, the FASB issued an ASU on the reporting of discontinued operations that raised the threshold for classification of assets “held for sale” as discontinued operations. Under this ASU, a discontinued operation is (i) a component of an entity or group of components that has been disposed of by sale, that has been disposed of other than by sale, or that is classified as “held for sale” and represents a strategic shift that has had or will have a major effect on an entity’s operations and financial results or (ii) an acquired business or non-profit activity that is classified as “held for sale” on the date of the acquisition. A strategic shift that has or will have a major effect on an entity’s operations and financial results could include the disposal of (i) a major line of business, (ii) a major geographic area, (iii) a major equity method investment, or (iv) other major parts of an entity. The ASU also allows for an entity to report a discontinued operation if it has certain continuing cash flows or involvement with the component after the disposal. We adopted this ASU on October 1, 2014. This ASU requires prospective application and since our adoption, no additional real estate met the criteria for classification as discontinued operations in our consolidated financial statements. The adoption of the ASU did not impact assets classified as discontinued operations prior to the adoption.
	Basis of presentation and consolidation
	The accompanying consolidated financial statements include the accounts of Alexandria and its consolidated subsidiaries. All significant intercompany balances and transactions have been eliminated.
	In certain circumstances, we may enter into joint venture arrangements with outside partners. On a quarterly basis, we evaluate each joint venture arrangement under the VIE model, and if the entity is determined not to be a VIE, then we evaluate the entity under the voting model to determine if the entity should be consolidated.
	Under the VIE model, an entity is determined to be a VIE if it has any of the following characteristics:
	•	The entity does not have sufficient equity to finance its activities without additional subordinated financial support;
	•	The equity holders, as a group, lack the characteristics of a controlling financial interest; or
	•	The legal entity is established with non-substantive voting rights.
	If an entity is determined to be a VIE, we evaluate whether or not we are the primary beneficiary using qualitative analyses. Factors considered include, but are not limited to, the purpose and design of the VIE, risks that the VIE was designed to create and pass through, the form of our ownership interest, our representation on the entity’s governing body, the size and seniority of our investment, our ability to participate in policy-making decisions, and the rights of the other investors to participate in the decision-making process and/or liquidate the venture, if applicable. We consolidate VIEs whenever we determine that we are the primary beneficiary.
	If an entity is determined not to be a VIE, we then evaluate such entity under the voting model. Under the voting model, if we are the general partner or managing member, or have a similar role that can direct the operations of the entity, we have a presumption that we control the entity and we should consolidate regardless of our ownership percentage. If we determine that the other equity holders have any one of the following rights, it is assumed that we do not control the entity and therefore should not consolidate the entity: (i) the substantive ability to dissolve the entity or remove us from the lead role of the entity, or (ii) substantive rights that allow them to participate in the activities that most significantly impact the entity’s economic performance.
	As of December 31, 2014, we had two joint ventures that did not meet the requirements for consolidation and were accounted for under the equity method of accounting. Refer to Note 3 – “Investments in Real Estate,” appearing elsewhere in this annual report on Form 10-K, for further information on our unconsolidated joint ventures.
	Use of estimates
	The preparation of consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, and equity; the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements; and the amounts of revenues and expenses during the reporting period.  Actual results could materially differ from those estimates.
	Operating segment
	We are engaged in the business of providing office/laboratory and tech office space for lease to the science and technology industries. Our properties are similar in that they provide space for lease to the science and technology industries, consist of improvements that are generic and reusable for the science and technology industries, are primarily located in urban innovation cluster submarkets, and have similar economic characteristics. Our chief operating decision maker reviews financial information for our entire consolidated operations when making decisions on how to allocate resources and in assessing our operating performance or individual properties when determining real estate decisions. The financial information disclosed herein represents all of the financial information related to our principal operating segment.
	International operations
	The functional currency for our subsidiaries operating in the U.S. is the U.S. dollar. We have five properties in Canada, two properties in China, seven operating properties in India, and various land parcels in India. The functional currencies for our foreign subsidiaries are the local currencies in each respective country. The assets and liabilities of our foreign subsidiaries are translated into U.S. dollars at the exchange rate in effect as of the financial statement date. Income statement accounts of our foreign subsidiaries are translated using the average exchange rate for the periods presented. Gains or losses resulting from the translation are classified in accumulated other comprehensive loss as a separate component of total equity.
	The appropriate amounts of foreign exchange rate gains or losses classified in accumulated other comprehensive loss will be reflected in our consolidated statements of income when there is a sale or partial sale of our investment in these operations or upon a complete or substantially complete liquidation of the investment.
	Investments in real estate and properties classified as “held for sale”
	We recognize real estate acquired (including the intangible value of above or below market leases, acquired in-place leases, client tenant relationships, and other intangible assets or liabilities), liabilities assumed, and any noncontrolling interest in an acquired entity at their fair value as of the acquisition date.  If there is a bargain fixed-rate renewal option for the period beyond the non-cancelable lease term of an in-place lease, we evaluate factors such as the business conditions in the industry in which the lessee operates, the economic conditions in the area in which the property is located, and the ability of the lessee to sublease the property during the renewal term, in order to determine the likelihood that the lessee will renew.  When we determine there is reasonable assurance that such bargain purchase option will be exercised, we consider its impact in determining the intangible value of such lease and its related amortization period.  The value of tangible assets acquired is based upon our estimation of value on an “as if vacant” basis.  The value of acquired in-place leases includes the estimated costs during the hypothetical lease-up period and other costs that would have been incurred in the execution of similar leases, considering market conditions at the acquisition date of the acquired in-place lease.  We assess the fair value of tangible and intangible assets based on numerous factors, including estimated cash flow projections that utilize appropriate discount and capitalization rates and available market information.  Estimates of future cash flows are based on a number of factors, including the historical operating results, known trends, and market/economic conditions that may affect the property.  We also recognize the fair values of assets acquired, the liabilities assumed, and any noncontrolling interest in acquisitions of less than a 100% interest when the acquisition constitutes a change in control of the acquired entity.  Acquisition-related costs related to the acquisition of businesses, including real estate acquired with in-place leases, are expensed as incurred.
	The values allocated to buildings and building improvements, land improvements, tenant improvements, and equipment are depreciated on a straight-line basis using the shorter of the term of the respective ground lease and up to 40 years for buildings and building improvements, an estimated life of 20 years for land improvements, the respective lease term for tenant improvements, and the estimated useful life for equipment. The values of acquired above and below market leases are amortized over the terms of the related leases and recognized as either an increase (for below market leases) or a decrease (for above market leases) to rental income. The values of acquired in-place leases are classified in other assets in the accompanying consolidated balance sheets, and amortized over the remaining terms of the related leases.
	We are required to capitalize project costs, including predevelopment costs, interest, property taxes, insurance, and other costs directly related and essential to the development, redevelopment, predevelopment, or construction of a project.  Capitalization of development, redevelopment, and construction costs is required while activities are ongoing to prepare an asset for its intended use.  Fluctuations in our development, redevelopment, and construction activities could result in significant changes to total expenses and net income.  Costs incurred after a project is substantially complete and ready for its intended use are expensed as incurred.  Should development, redevelopment, or construction activity cease, interest, property taxes, insurance, and certain other costs would no longer be eligible for capitalization and would be expensed as incurred.  Expenditures for repairs and maintenance are expensed as incurred.
	A property is classified as “held for sale” when all of the following criteria for a plan of sale have been met: (i) management, having the authority to approve the action, commits to a plan to sell the property; (ii) the property is available for immediate sale in its present condition, subject only to terms that are usual and customary; (iii) an active program to locate a buyer and other actions required to complete the plan to sell have been initiated; (iv) the sale of the property is probable and is expected to be completed within one year; (v) the property is being actively marketed for sale at a price that is reasonable in relation to its current fair value; and (vi) actions necessary to complete the plan of sale indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Depreciation of assets ceases upon designation of a property as “held for sale.” Prior to adoption of the new discontinued ASU mentioned above, the operations of properties “held for sale” were classified as discontinued operations in our consolidated statements of income, and amounts for all prior periods presented were reclassified from continuing operations to discontinued operations.
	Subsequent to the adoption of the new discontinued operations ASU mentioned above, if the disposal of the property represents a strategic shift that has (or will have) a major effect on our operations or financial results, such as (i) a major line of business, (ii) a major geographic area, (iii) a major equity method investment, or (iv) other major parts of an entity, then the operations of the property “held for sale,” including any interest expense directly attributable to it, are classified as discontinued operations in our consolidated statements of income, and amounts for all prior periods presented are reclassified from continuing operations to discontinued operations. The disposal of an individual property generally will not represent a strategic shift and therefore not meet the criteria for classification as discontinued operations.
	Impairment of long-lived assets
	Long-lived assets to be held and used, including our rental properties, CIP, land held for development, and intangibles, are individually evaluated for impairment when conditions exist that may indicate that the amount of a long-lived asset may not be recoverable.  The amount of a long-lived asset to be held and used is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset.  Impairment indicators or triggering events for long-lived assets to be held and used, including our rental properties, CIP, and land held for development, are assessed by project and include significant fluctuations in estimated revenue less rental operating expense, occupancy changes, significant near-term lease expirations, current and historical operating and/or cash flow losses, construction costs, estimated completion dates, rental rates, and other market factors.  We assess the expected undiscounted cash flows based upon numerous factors, including, but not limited to, construction costs, available market information, current and historical operating results, known trends, current market/economic conditions that may affect the property, and our assumptions about the use of the asset, including, if necessary, a probability-weighted approach if multiple outcomes are under consideration.  Upon determination that an impairment has occurred, a write-down is recognized to reduce the carrying amount to its estimated fair value.  If an impairment loss is not required to be recognized, the recognition of depreciation is adjusted prospectively, as necessary, to reduce the carrying amount of the real estate to its estimated disposition value over the remaining period that the real estate is expected to be held and used.  We may adjust depreciation of properties that are expected to be disposed of or redeveloped prior to the end of their useful lives.
	We use the “held for sale” impairment model for our properties classified as “held for sale.”  The “held for sale” impairment model is different from the held and used impairment model.  Under the “held for sale” impairment model, an impairment loss is recognized if the amount of the long-lived asset classified as “held for sale” exceeds its fair value less cost to sell.  Because of these two different models, it is possible for a long-lived asset previously classified as held and used to require the recognition of an impairment charge upon classification as “held for sale.”
	Cash and cash equivalents
	We consider all highly liquid investments with original maturities of three months or less when purchased to be cash and cash equivalents. The majority of our cash and cash equivalents are held at major commercial banks in accounts that may at times exceed the FDIC-insured limit of $250,000. We have not experienced any losses to date on our invested cash.
	Restricted cash
	Restricted cash primarily consists of funds held in trust under the terms of our secured bank loans, funds held in escrow related to construction projects, and funds held for various other deposits.
	Investments
	We hold equity investments in certain publicly traded companies and investments in certain privately held entities and limited partnerships primarily involved in the science and technology industries.  All of our investments in actively traded public companies are considered “available for sale” and are reflected in the accompanying consolidated balance sheets at fair value.  Fair value has been determined based upon the closing price as of each balance sheet date, with unrealized gains and losses shown as a separate component of comprehensive income.  The classification of each investment is determined at the time each investment is made, and such determination is reevaluated at each balance sheet date.  The cost of each investment sold is determined by the specific identification method, with realized gains or losses classified in other income in the accompanying consolidated statements of income.  Investments in privately held entities are generally accounted for under the cost method when our interest in the entity is so minor that we have virtually no influence over the entity’s operating and financial policies. Certain investments in privately held entities are accounted for under the equity method unless our interest in the entity is deemed to be so minor that we have virtually no influence over the entity’s operating and financial policies. Under the equity method of accounting, we recognize our investment initially at cost and adjust the amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment.  Additionally, we limit our ownership percentage in the voting stock of each individual entity to less than 10%.  As of December 31, 2014 and 2013, our ownership percentage in the voting stock of each individual entity was less than 10%.
	We monitor each of our equity investments throughout the year for new developments, including operating results, results of clinical trials, capital-raising events, and merger and acquisition activities. Individual investments are evaluated for impairment when changes in conditions may indicate an impairment exists.  The factors that we consider in making these assessments include, but are not limited to, market prices, market conditions, available financing, prospects for favorable or unfavorable clinical trial results, new product initiatives, and new collaborative agreements.  If there are no identified events or changes in circumstances that might have an adverse effect on our cost method investments, we do not estimate the investment’s fair value.  For all of our investments, if a decline in the fair value of an investment below the carrying value is determined to be other than temporary, such investment is written down to its estimated fair value with a charge to current earnings.
	Leasing costs
	Costs directly related and essential to our leasing activities are capitalized and amortized on a straight-line basis over the term of the related lease. Costs related to unsuccessful leasing opportunities are expensed.
	Loan fees and costs
	Fees and costs incurred in obtaining long-term financing are capitalized. Capitalized amounts are amortized over the term of the related loan, and the amortization is classified in interest expense in the accompanying consolidated statements of income.
	Interest rate swap agreements
	We are exposed to certain risks arising from both our business operations and economic conditions. We principally manage our exposures to a wide variety of business and operational risks through management of our core business activities. We manage economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of our debt funding and the use of interest rate swap agreements. Specifically, we enter into interest rate swap agreements to manage exposures that arise from business activities that result in the payment of future known and uncertain cash amounts, the values of which are determined by interest rates. Our interest rate swap agreements are used to manage differences in the amount, timing, and duration of our known or expected cash payments principally related to our borrowings based on LIBOR. We do not use derivatives for trading or speculative purposes, and currently all of our derivatives are designated as hedges. Our objectives in using interest rate swap agreements are to add stability to interest expense and to manage our exposure to interest rate movements in accordance with our interest rate risk management strategy. All of our interest rate swaps are designated as cash flow hedges. Interest rate swap agreements designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the interest rate swap agreements without exchange of the underlying notional amount of interest rate swap agreements.
	We utilize interest rate swap agreements to hedge a portion of our exposure to variable interest rates primarily associated with borrowings based on LIBOR. We recognize our interest rate swap agreements as either assets or liabilities on the balance sheet at fair value.  The accounting for changes in fair value (i.e., gains or losses) of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and, further, on the type of hedging relationship. For those derivative instruments that are designated and qualify as hedging instruments, a company must designate the hedging instrument, based on the hedged exposure, as a fair value hedge, a cash flow hedge, or a hedge of a net investment in a foreign operation. Our interest rate swap agreements are considered cash flow hedges because they are designated and qualify as hedges of the exposure to variability in expected future cash flows. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the earnings effect of the hedged transactions in a cash flow hedge. All of our interest rate swap agreements meet the criteria to be deemed “highly effective” in reducing our exposure to variable interest rates. We formally document all relationships between interest rate swap agreements and hedged items, including the method for evaluating effectiveness and the risk strategy. We make an assessment at the inception of each interest rate swap agreement and on an ongoing basis to determine whether these instruments are “highly effective” in offsetting changes in cash flows associated with the hedged items. The ineffective portion of each interest rate swap agreement is immediately recognized in earnings. While we intend to continue to meet the conditions for such hedge accounting, if swaps did not qualify as “highly effective,” the changes in the fair values of the derivatives used as hedges would be reflected in earnings.
	The effective portion of changes in the fair value of our interest rate swap agreements that are designated and that qualify as cash flow hedges is recognized in accumulated other comprehensive income. Amounts classified in accumulated other comprehensive income will be reclassified into earnings in the period during which the hedged transactions affect earnings.
	The fair value of each interest rate swap agreement is determined using widely accepted valuation techniques including discounted cash flow analyses on the expected cash flows of each derivative. These analyses reflect the contractual terms of the derivatives, including the period to maturity, and use observable market-based inputs, including interest rate curves and implied volatilities. The fair values of our interest rate swap agreements are determined using the market standard methodology of netting the discounted future fixed cash payments and the discounted expected variable cash receipts. The variable cash receipts are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves. The fair value calculation also includes an amount for risk of non-performance of our counterparties using “significant unobservable inputs” such as estimates of current credit spreads to evaluate the likelihood of default, which we have determined to be insignificant to the overall fair value of our interest rate swap agreements.
	Recognition of rental income and tenant recoveries
	Rental income from leases is recognized on a straight-line basis over the respective lease terms.  We classify amounts currently recognized as income, and expected to be received in later years, as deferred rent in the accompanying consolidated balance sheets.  Amounts received currently, but recognized as income in future years, are classified in accounts payable, accrued expenses, and tenant security deposits in the accompanying consolidated balance sheets.  We commence recognition of rental income at the date the property is ready for its intended use and the client tenant takes possession of or controls the physical use of the property.
	Tenant recoveries related to reimbursement of real estate taxes, insurance, utilities, repairs and maintenance, common area expenses, and other operating expenses are recognized as revenue in the period during which the applicable expenses are incurred.
	Tenant receivables consist primarily of amounts due for contractual lease payments, reimbursements of common area maintenance expenses, property taxes, and other expenses recoverable from client tenants.  Tenant receivables are expected to be collected within one year.  We may maintain an allowance for estimated losses that may result from the inability of our client tenants to make payments required under the terms of the lease and for tenant recoveries due.  If a client tenant fails to make contractual payments beyond any allowance, we may recognize additional bad debt expense in future periods equal to the amount of uncollectible rent and deferred rent receivables arising from the straight-lining of rent.  As of December 31, 2014 and 2013, we had no allowance for estimated losses.
	Monitoring client tenant credit quality
	During the term of each lease, we monitor the credit quality of our client tenants by (i) reviewing the credit rating of client tenants that are rated by a nationally recognized credit rating agency, (ii) reviewing financial statements of the client tenants that are publicly available or that are required to be delivered to us pursuant to the applicable lease, (iii) monitoring news reports regarding our client tenants and their respective businesses, and (iv) monitoring the timeliness of lease payments. We have a team of employees who, among them, have graduate and undergraduate degrees in biology, chemistry, and industrial biotechnology and experience in the science and technology industries, as well as in finance. Our research team is responsible for assessing and monitoring the credit quality of our client tenants and any material changes in credit quality.
	Interest income
	Interest income was approximately $4.2 million, $4.6 million, and $3.4 million during the years ended December 31, 2014, 2013, and 2012, respectively.  Interest income is included in other income in the accompanying consolidated statements of income.
	Share-based compensation expense
	We have historically issued two forms of share-based compensation under our equity incentive plan: options to purchase common stock (“options”) and restricted share awards. We have not granted any options since 2002. We recognize all share-based compensation in the income statement based on the grant date fair value. Compensation expense is recognized on a straight-line basis over the period during which the employee is required to provide services in exchange for the award (the vesting period). We recognize share-based compensation based on awards that are ultimately expected to vest. As a result, future forfeitures of awards are estimated at the time of grant and revised in subsequent periods, as necessary, if actual forfeitures differ from those estimates. In most cases, no compensation cost is recognized for equity instruments that are forfeited or are anticipated to be forfeited. The majority of our restricted share awards contain time-based vesting restrictions and the fair value of these awards is calculated based on the market value of the common stock on the grant date. Certain restricted share awards contain vesting restrictions based upon the satisfaction of levels of performance and market conditions. The fair value of these awards is determined using a Monte Carlo simulation pricing model. Failure to satisfy the threshold performance and/or market conditions will result in the forfeiture of shares. Forfeiture of share awards with time-based or performance-based restrictions results in a reversal of previously recognized share-based compensation expense. Forfeiture of share awards with market-based restrictions does not result in a reversal of previously recognized share-based compensation expense.

Investments_in_real_estate_Not

Investments in real estate (Notes)	12 Months Ended
	Dec. 31, 2014
Real Estate [Abstract]
Investments in real estate, net	Investments in real estate
	Our investments in real estate consisted of the following as of December 31, 2014 and 2013 (in thousands):
			31-Dec-14			31-Dec-13
	Land (related to rental properties)		$	624,681		$	553,388
	Buildings and building improvements		6,171,504			5,714,673
	Other improvements		192,128			174,147
	Rental properties		6,988,313			6,442,208
	CIP/current value-creation projects:
	Current development in North America		500,894			511,838
	Current redevelopment in North America		42,482			8,856
	Current development in Asia		14,065			60,928
			557,441			581,622
	Near-term value-creation projects in North America (CIP):
	50, 60, and 100 Binney Street		321,907			284,672
	Other projects		107,471			97,617
			429,378			382,289
	Future value-creation projects:
	North America		175,175			176,063
	Asia		78,548			77,251
			253,723			253,314
	Land under sales contract		—			22,943
	Near-term and future value-creation projects		683,101			658,546
	Gross investments in real estate		8,228,855			7,682,376
	Equity method of accounting – unconsolidated joint ventures		117,406			46,644
	Gross investments in real estate – including unconsolidated joint ventures		8,346,261			7,729,020
	Less: accumulated depreciation		(1,120,245		)	(952,106		)
	Investments in real estate		$	7,226,016		$	6,776,914
	Acquisitions
	During the year ended December 31, 2014, we acquired a total of six operating properties aggregating 405,353 RSF, for an aggregate purchase price of $115.0 million and assumed secured notes payable aggregating $48.3 million. During the year ended December 31, 2014, we also acquired one land parcel aggregating 300,000 square feet for a purchase price of $50.0 million. As of December 31, 2014, the six operating properties acquired were 100% leased and the one land parcel was 100% under lease negotiations for a future ground-up development.
	In addition, during the year ended December 31, 2014, we entered into a new joint venture (described below) and the joint venture acquired two land parcels in the San Francisco Bay Area market for a purchase price of $125.0 million.
	Acquired below market leases
	The balances of acquired below market leases, and related accumulated amortization, classified in accounts payable, accrued expenses, and tenant security deposits in the accompanying consolidated balance sheets as of December 31, 2014 and 2013, were as follows (in thousands):
			31-Dec-14			31-Dec-13
	Acquired below market leases		$	55,955		$	55,599
	Accumulated amortization		(47,145		)	(44,194		)
			$	8,810		$	11,405
	For the years ended December 31, 2014, 2013, and 2012, we recognized an increase in rental income of approximately $2.8 million, $3.3 million, and $3.2 million, respectively, related to the amortization of acquired below market leases. The weighted average amortization period of the value of acquired below market leases was approximately 2.3 years as of December 31, 2014. The estimated annual amortization of the value of acquired below market leases is as follows (in thousands):
	Year		Amount
	2015		$	2,861
	2016		2,455
	2017		2,251
	2018		705
	2019		209
	Thereafter		329
	Total		$	8,810
	Acquired in-place leases
	The balances of acquired in-place leases, and related accumulated amortization, are classified in other assets in the accompanying consolidated balance sheets. As of December 31, 2014 and 2013, these amounts were as follows (in thousands):
			31-Dec-14			31-Dec-13
	Acquired in-place leases		$	51,395		$	48,189
	Accumulated amortization		(32,123		)	(28,927		)
			$	19,272		$	19,262
	Amortization for these intangible assets, classified in depreciation and amortization expense in the accompanying consolidated statements of income, was approximately $3.5 million, $2.4 million, and $2.7 million, for the years ended December 31, 2014, 2013, and 2012, respectively. The weighted average amortization period of the value of acquired in-place leases was approximately 7.3 years as of December 31, 2014. The estimated annual amortization of the value of acquired in-place leases is as follows (in thousands):
	Year		Amount
	2015		$	3,663
	2016		2,709
	2017		2,513
	2018		2,377
	2019		2,095
	Thereafter		5,915
	Total		$	19,272
	Minimum lease payments
	Minimum lease payments to be received under the terms of the operating lease agreements, excluding expense reimbursements, in effect as of December 31, 2014, are outlined in the table below (in thousands):
	Year		Amount
	2015		$	496,797
2016		488,626
2017		466,829
2018		423,234
2019		373,509
Thereafter		1,995,904
Total		$	4,244,899
Sales of real estate assets and related impairment charges
During the year ended December 31, 2014, we sold three income-producing assets located in the San Diego market, aggregating 62,346 RSF, for an aggregate sales price of $7.4 million, and recognized an aggregate gain of $1.8 million on the sales. These three income-producing assets qualified for classification as discontinued operations prior to October 1, 2014, and as such, the gain on sales of real estate – rental properties associated to the sale of these properties is included in income from discontinued operations in the accompanying consolidated statements of income.
In addition, during the year ended December 31, 2014, and excluding our sale of land parcels in South San Francisco discussed below, we completed the sale of six parcels of land in various markets, aggregating 662,950 RSF for an aggregate sales price of $48.4 million and recognized an aggregate gain on sales of real estate – land parcels of $6.4 million. These gains are classified in gain on sales of real estate – land parcels below income from discontinued operations in the accompanying consolidated statements of income.
On a quarterly basis, we review current activities and changes in the business conditions of all of our properties prior to and subsequent to the end of each quarter to determine the existence of any “triggering events” requiring an impairment analysis. If triggering events are identified, we review an estimate of the future undiscounted cash flows for the properties, including a probability-weighted approach if multiple outcomes are under consideration.
During the fourth quarter of 2014, we determined that the following real estate assets each met the criteria for classification as “held for sale” including, among others, the following: (i) we reached a point of commitment to sell the real estate, including approval of the sale by our Board of Directors, (ii) the sale was probable and would be completed within one year, and (iii) it was unlikely that significant changes to the sales plan would be made or the plan would be withdrawn. Prior to classification as “held for sale,” these properties were classified as “held and used.” The decisions to dispose of these assets did not represent a strategic shift in our operations or financial results. As a result, these assets did not qualify for classification as discontinued operations.
South San Francisco land parcels
As of September 30, 2014, nine non-contiguous land parcels with seven industrial buildings in the South San Francisco submarket of the San Francisco Bay Area were held for future ground-up development. The projected undiscounted cash flows from these projects exceeded our projected costs to develop these sites. Our most recent ground-up development in South San Francisco was completed and delivered to a client-tenant in the third quarter of 2014.
During the three months ended December 31, 2014, we evaluated an offer from an entity that operates, redevelops, and develops industrial properties. Zoning laws in South San Francisco do not permit the re-leasing or extension of an existing industrial lease. As a result, the zoning restrictions significantly limit the potential interest in this real estate and the likelihood that this entity would acquire these parcels for industrial use. We intended to hold these parcels for future development if we failed to reach reasonable terms with this entity. As a result, we completed a probability-weighted cash flow analysis for these parcels based on the potential sale and development scenarios and determined the estimated undiscounted cash flows exceeded the carrying value of these land parcels.
In December 2014, we determined that these land parcels met the criteria for classification as “held for sale” including, among others, the following: (i) committing to sell the real estate, (ii) obtaining approval from our Board of Directors, and (iii) determining that the sale was probable within one year. Upon classification as “held for sale,” we recognized an impairment charge of $24.7 million to lower the carrying costs of the real estate to its estimated fair value less cost to sell. On December 30, 2014, we completed the sale of these land parcels for $31.0 million.
661 University Avenue
As of September 30, 2014, we had land and land improvements in Toronto, Canada that were classified in rental properties. This real estate was leased to a tenant and the tenant was completing the construction of a 780,540 RSF building. Rental payments from the tenant were anticipated to commence in the future upon completion and stabilization of the building. In December 2014, we determined that this property met the criteria to be classified as “held for sale” and accordingly we recognized an impairment charge of $16.6 million to lower the carrying costs of the property to its estimated fair value less cost to sell. Approximately 75% of the impairment recognized related to changes in the foreign exchange rate, estimated transfer taxes, and closing costs. In January 2015, we completed the sale for $54.1 million.
500 Forbes Boulevard
During the three months ended December 31, 2014, 500 Forbes Boulevard, a 155,685 RSF building located in our South San Francisco submarket, met the criteria for classification as “held for sale” and accordingly, we recognized an impairment charge of $9.6 million to reduce the carrying costs in the property to the estimated fair value less cost to sell of $107.8 million. The annualized revenues less operating expenses for this property for the three months ended December 31, 2014, were approximately $5.5 million, representing a yield on our remaining book value of approximately 5.1% and the property is leased to an investment-grade rated client tenant through 2019. We expect to complete the sale of this property in 2015.
Current value-creation development and redevelopment projects
As of December 31, 2014, we had seven ground-up development projects in process in North America aggregating 1,727,758 RSF, including two unconsolidated joint venture development projects. We also had two projects undergoing redevelopment in North America aggregating 143,777 RSF.
Investments in unconsolidated joint ventures
We account for our investments in joint ventures described below under the equity method of accounting. Refer to our consolidation policy described in Note 2 – “Basis of Presentation and Summary of Significant Accounting Policies.”
360 Longwood Avenue
We are currently developing a building aggregating 413,536 RSF in the Longwood Medical Area of the Greater Boston market through an unconsolidated joint venture. The cost at completion for this unconsolidated joint venture real estate project is approximately $350.0 million. The project is currently 38% occupied by Dana-Farber Cancer Institute, Inc. and this space was placed into operations in late September 2014. The joint venture has a construction loan with commitments aggregating $213.2 million, with $159.9 million outstanding as of December 31, 2014. The remaining cost to complete the development is expected to be funded primarily from the remaining commitments of $53.3 million under the construction loan. The construction loan bears interest at LIBOR+3.75%, with a floor of 5.25%, and has a maturity date of April 1, 2019, inclusive of two separate options to extend the stated maturity date of April 1, 2017, by one year.
We have a 27.5% interest in this unconsolidated joint venture that we account for under the equity method of accounting. Our investment under the equity method of accounting was $49.1 million as of December 31, 2014, and is classified in investments in real estate on our accompanying consolidated balance sheets.
1455/1515 Third Street
During the three months ended September 30, 2014, Alexandria and Uber entered into a joint venture agreement and acquired two land parcels supporting the development of two buildings aggregating 422,980 RSF at 1455/1515 Third Street in the Mission Bay submarket of the San Francisco Bay Area for a total purchase price of $125.0 million. We have a 51% interest and Uber has a 49% interest in this unconsolidated joint venture. We account for our investment in this joint venture under the equity method of accounting. Our investment under the equity method of accounting was $68.3 million as of December 31, 2014, and is classified in investments in real estate on our accompanying consolidated balance sheets. The project is 100% leased to Uber for a 15-year term, commencing upon completion of development.
Near-term value creation projects in North America (construction in progress)
Land undergoing predevelopment activities is classified as construction in progress and is undergoing activities prior to commencement of construction of aboveground building improvements.  We generally will not commence ground-up development of any parcels without first securing pre-leasing for such space, except when there is solid market demand.  If aboveground construction is not initiated at completion of predevelopment activities, the land parcel will be classified as future value-creation projects.  Our objective with predevelopment is to reduce the time it takes to deliver projects to prospective client tenants.  Additionally, during predevelopment, we focus on the design of cost-effective buildings with generic and reusable infrastructure to accommodate single-tenancy and multi-tenancy. As of December 31, 2014, we had $429.4 million of land undergoing predevelopment activities in North America aggregating 2.7 million RSF. The largest project in this category consists of 1.0 million RSF at our Alexandria Center® at Kendall Square project in the Greater Boston Area in East Cambridge, Massachusetts.
Predevelopment costs generally include the following activities prior to commencement of vertical construction:
•	Traditional predevelopment costs, including entitlement, design, construction drawings, BIM (3-D virtual modeling), budgeting, sustainability and energy optimization reviews, permitting, and planning for all aspects of the project; and
•	Site and infrastructure construction costs, including belowground site work, utility connections, land grading, drainage, egress and regress access points, foundation, and other costs to prepare the site for construction of aboveground building improvements. For example, site and infrastructure costs for the 1.0 million RSF primarily related to 50, 60, and 100 Binney Street at our Alexandria Center® at Kendall Square project are classified as predevelopment prior to commencement of vertical construction.
Future value-creation projects
Future value-creation projects represent land that we plan to develop in the future, but for which, as of each period presented, no construction or predevelopment activities were ongoing. As a result, interest, property taxes, insurance, and other costs are expensed as incurred. As of December 31, 2014, we had $253.7 million of land held for future development supporting an aggregate of 10.1 million RSF of ground-up development.

Deferred_leasing_and_financing

Deferred leasing and financing costs (Notes)	12 Months Ended
	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing and financing costs	Deferred leasing and financing costs
	The following table summarizes our deferred leasing and financing costs, as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014			2013
	Deferred leasing costs	$	333,109		$	293,879
	Accumulated amortization	(174,194		)	(146,881		)
		158,915			146,998
	Deferred financing costs	126,687			118,078
	Accumulated amortization	(83,804		)	(72,418		)
		42,883			45,660
	Deferred leasing and financing costs	$	201,798		$	192,658

Investments_Notes

Investments (Notes)	12 Months Ended
	Dec. 31, 2014
Investments [Abstract]
Investments	Investments
	We hold investments in certain publicly traded companies, privately held entities, and limited partnership funds involved primarily in life science and related industries.  Our investments in privately held entities and limited partnership funds are accounted for under the cost method. Certain investments in privately held entities are accounted for under the equity method unless our interest in the entity is deemed to be so minor that we have virtually no influence over the entity’s operating and financial policies. Under the equity method of accounting, we recognize our investment initially at cost and adjust the amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment. Our investments in publicly traded companies are principally marketable equity securities which are accounted for as “available for sale” securities that are carried at their fair values.  Investments in “available for sale” securities with gross unrealized losses as of December 31, 2014, had been in a continuous unrealized loss position for less than 12 months. We have the ability and intent to hold these investments for a reasonable period of time sufficient for the recovery of our investment. We believe that these unrealized losses are temporary and accordingly there are no other-than-temporary impairments in accumulated other comprehensive income related to “available for sale” securities as of December 31, 2014 or 2013.
	The following table summarizes our investments as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014			2013
	“Available-for-sale” marketable equity securities, at cost basis	$	21,898		$	2,879
	Unrealized gains	53,625			2,177
	Unrealized losses	(1,258		)	(587		)
	“Available-for-sale” marketable equity securities, at fair value	74,265			4,469
	Investments accounted for under cost method	162,124			135,819
	Investments	$	236,389		$	140,288
	The following table outlines our investment income, which is classified in other income in the accompanying consolidated statements of income (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Investment gains	$	11,613		$	7,050		$	15,018
	Investment losses	(9,287		)	(1,480		)	(2,637		)
	Investment income	$	2,326		$	5,570		$	12,381

Fair_value_measurements_Notes

Fair value measurements (Notes)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements
	We are required to disclose fair value information about all financial instruments, whether or not recognized in the balance sheet, for which it is practicable to estimate fair value.  We measure and disclose the estimated fair value of financial assets and liabilities utilizing a fair value hierarchy that distinguishes between data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions.  This hierarchy consists of three broad levels, as follows: (i) quoted prices in active markets for identical assets or liabilities, (ii) “significant other observable inputs,” and (iii) “significant unobservable inputs.”  “Significant other observable inputs” can include quoted prices for similar assets or liabilities in active markets, as well as inputs that are observable for the asset or liability, such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals.  “Significant unobservable inputs” are typically based on an entity’s own assumptions, since there is little, if any, related market activity.  In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety.  Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability.  There were no transfers between the levels in the fair value hierarchy during the years ended December 31, 2014 and 2013.
	The following tables set forth the assets and liabilities that we measure at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2014 and 2013 (in thousands):
						31-Dec-14
	Description		Total			Quoted Prices in			Significant			Significant
						Active Markets			Other			Unobservable
						for Identical			Observable			Inputs
						Assets			Inputs
	Assets:
	“Available-for-sale securities”		$	74,265		$	74,265		$	—		$	—
	Liabilities:
	Interest rate swap agreements		$	909		$	—		$	909		$	—
						31-Dec-13
	Description		Total			Quoted Prices in			Significant			Significant
						Active Markets			Other			Unobservable
						for Identical			Observable			Inputs
						Assets			Inputs
	Assets:
	“Available-for-sale securities”		$	4,469		$	4,469		$	—		$	—
	Interest rate swap agreements		$	2,870		$	—		$	2,870		$	—
	Liabilities:
	Interest rate swap agreements		$	6,191		$	—		$	6,191		$	—
	The carrying values of cash and cash equivalents, restricted cash, tenant receivables, other assets, accounts payable, accrued expenses, and tenant security deposits approximate fair value.  Our “available-for-sale” securities and our interest rate swap agreements, respectively, have been recognized at fair value.  Refer to Note 8 – “Interest Rate Swap Agreements,” for further details on our interest rate swap agreements. The fair values of our secured notes payable, unsecured senior notes payable, unsecured senior line of credit, and unsecured senior bank term loans were estimated using widely accepted valuation techniques, including discounted cash flow analyses of “significant other observable inputs” such as available market information on discount and borrowing rates with similar terms, maturities, and credit ratings.  Because the valuations of our financial instruments are based on these types of estimates, the actual fair value of our financial instruments may differ materially if our estimates do not prove to be accurate.  Additionally, the use of different market assumptions or estimation methods may have a material effect on the estimated fair value amounts.
	As of December 31, 2014 and 2013, the book and estimated fair values of our marketable equity securities, interest rate swap agreements, secured notes payable, unsecured senior notes payable, unsecured senior line of credit, and unsecured senior bank term loans were as follows (in thousands):
		31-Dec-14						31-Dec-13
		Book Value			Fair Value			Book Value			Fair Value
	Assets:
	Marketable equity securities	$	74,265		$	74,265		$	4,469		$	4,469
	Interest rate swap agreements	$	—		$	—		$	2,870		$	2,870
	Liabilities:
	Interest rate swap agreements	$	909		$	909		$	6,191		$	6,191
	Secured notes payable	$	652,209		$	693,338		$	708,831		$	736,772
	Unsecured senior notes payable	$	1,747,370		$	1,793,255		$	1,048,230		$	1,043,125
	Unsecured senior line of credit	$	304,000		$	304,369		$	204,000		$	193,714
	Unsecured senior bank term loans	$	975,000		$	976,010		$	1,100,000		$	1,099,897
	Fair value measurements for other than on a recurring basis
	Refer to discussions at Note 3 – “Investments in Real Estate.”

Secured_and_unsecured_senior_d

Secured and unsecured senior debt (Notes)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Secured and unsecured senior debt	Secured and unsecured senior debt
	The following table summarizes our secured and unsecured senior debt as of December 31, 2014 (dollars in thousands):
		Fixed Rate/Hedged				Unhedged				Total				Percentage of Total Debt			Weighted Average			Weighted Average
		Variable Rate				Variable Rate				Consolidated							Interest Rate at			Remaining Term
																	End of Period (1)			(in years)
	Secured notes payable	$	403,981			$	248,228			$	652,209			17.7	%		4.59	%		2.7
	Unsecured senior notes payable	1,747,370				—				1,747,370				47.5			3.98			8.3
	$1.5 billion unsecured senior line of credit	—				304,000				304,000				8.3			1.27			4
	2016 Unsecured Senior Bank Term Loan	350,000				25,000				375,000				10.2			1.42			1.6
	2019 Unsecured Senior Bank Term Loan	600,000				—				600,000				16.3			1.67			4
	Total/weighted average	$	3,101,351			$	577,228			$	3,678,579			100	%		3.23	%		5.6
	Percentage of total debt	84%				16%				100%
	-1	Represents the weighted average interest rate as of the end of the period plus the impact of debt premiums/discounts and our interest rate swap agreements. The weighted average interest rate excludes bank fees and amortization of loan fees.
	The following table summarizes our outstanding indebtedness and respective principal maturities as of
	December 31, 2014 (dollars in thousands):
			Stated			Weighted Average			Maturity Date(2)		Principal Payments Remaining for the Period Ending December 31,
	Debt		Rate			Interest Rate(1)					2015				2016				2017			2018			2019			Thereafter			Total
	Secured notes payable
	Maryland		5.64	%		4.5	%		6/1/15		$	5,777			$	—			$	—		$	—		$	—		$	—		$	5,777
	San Francisco Bay Area		L+1.50			1.66			7/1/15		46,792				—				—			—			—			—			46,792
	Greater Boston, San Francisco Bay Area, and San Diego		5.73			5.73			1/1/16		1,815				75,501				—			—			—			—			77,316
	Greater Boston, San Diego, and New York City		5.82			5.82			4/1/16		988				29,389				—			—			—			—			30,377
	San Diego		5.74			3			4/15/16		175				6,916				—			—			—			—			7,091
	San Francisco Bay Area		L+1.40			1.56			6/1/16		—				19,343				—			—			—			—			19,343
	San Francisco Bay Area		6.35			6.35			8/1/16		2,652				126,715				—			—			—			—			129,367
	Maryland		2.15			2.15			1/20/17		—				—				76,000			—			—			—			76,000
	Greater Boston		L+1.35			1.52			8/23/17		—				—				106,093			—			—			—			106,093
	San Diego, Maryland, and Seattle		7.75			7.75			4/1/20		1,570				1,696				1,832			1,979			2,138			104,352			113,567
	San Diego		4.66			4.66			1/1/23		1,403				1,464				1,540			1,614			1,692			31,674			39,387
	San Francisco Bay Area		6.5			6.5			6/1/37		18				19				20			22			23			728			830
	Unamortized premiums										214				55				—			—			—			—			269
	Secured notes payable average/subtotal		4.63	%		4.59					61,404				261,098				185,485			3,615			3,853			136,754			652,209
	2016 Unsecured Senior Bank Term Loan		L+1.20	%		1.42			7/31/16		—				375,000				—			—			—			—			375,000
	2019 Unsecured Senior Bank Term Loan		L+1.20	%		1.67			1/3/19		—				—				—			—			600,000			—			600,000
	$1.5 billion unsecured senior line of credit		L+1.10	%	(3)	1.27			1/3/19		—				—				—			—			304,000			—			304,000
	Unsecured senior notes payable		2.75	%		2.79			1/15/20		—				—				—			—			—			400,000			400,000
	Unsecured senior notes payable		4.6	%		4.61			4/1/22		—				—				—			—			—			550,000			550,000
	Unsecured senior notes payable		3.9	%		3.94			6/15/23		—				—				—			—			—			500,000			500,000
	Unsecured senior notes payable		4.5	%		4.51			7/30/29		—				—				—			—			—			300,000			300,000
	Unamortized discounts										(326		)		(337		)		(350		)	(362		)	(375		)	(880		)	(2,630		)
	Unsecured debt average/subtotal					2.94					(326		)		374,663				(350		)	(362		)	903,625			1,749,120			3,026,370
	Average/total					3.23	%				$	61,078			$	635,761			$	185,135		$	3,253		$	907,478		$	1,885,874		$	3,678,579
	Balloon payments										$	52,532			$	631,243			$	182,093		$	—		$	904,000		$	1,880,238		$	3,650,106
	Principal amortization										8,546				4,518				3,042			3,253			3,478			5,636			28,473
	Total consolidated debt										$	61,078			$	635,761			$	185,135		$	3,253		$	907,478		$	1,885,874		$	3,678,579
	Fixed-rate/hedged variable-rate debt										$	14,286			$	591,418			$	3,042		$	3,253		$	603,478		$	1,885,874		$	3,101,351
	Unhedged variable-rate debt										46,792				44,343				182,093			—			304,000			—			577,228
	Total consolidated debt										$	61,078			$	635,761			$	185,135		$	3,253		$	907,478		$	1,885,874		$	3,678,579
	-1	Represents the weighted average interest rate as of the end of the period plus the impact of debt premiums/discounts and our interest rate swap agreements. The weighted average interest rate excludes bank fees and amortization of loan fees.
	-2	Includes any extension options that we control.
	-3	In addition to the stated rate, the unsecured senior line of credit is subject to an annual facility fee of 0.20%, based on the aggregate commitments outstanding.
	2.75% and 4.50% Unsecured senior notes payable
	In July 2014, we completed an offering of $700 million unsecured senior notes payable at a weighted average interest rate of 3.50%. The offering consisted of $400 million of our 2.75% Unsecured Senior Notes and $300 million of our 4.50% Unsecured Senior Notes.  The 2.75% Unsecured Senior Notes were priced at 99.793% of the principal amount with a yield to maturity of 2.791% and are due on January 15, 2020. The 4.50% Unsecured Senior Notes were priced at 99.912% of the principal amount with a yield to maturity of 4.508% and are due on July 30, 2029.  We used the net proceeds of this offering to reduce variable-rate debt, including the partial prepayment of $125 million of our 2016 Unsecured Senior Bank Term Loan and to reduce the outstanding borrowings on our unsecured senior line by $569 million. In connection with the partial prepayment of $125 million of our 2016 Unsecured Senior Bank Term Loan, we recognized a loss on early extinguishment of debt related to the write-off of a portion of unamortized loan fees totaling $525 thousand in July 2014.
	3.90% Unsecured senior notes payable
	In June 2013, we completed a $500 million public offering of our 3.90% Unsecured Senior Notes.  The unsecured senior notes payable were priced at 99.712% of the principal amount with a yield to maturity of 3.94% and are due June 15, 2023.  We used the net proceeds of this offering initially to prepay $150 million of the outstanding principal balance on our 2016 Unsecured Senior Bank Term Loan, to reduce the outstanding borrowings on our unsecured senior line of credit to zero, and initially held the remaining proceeds in cash and cash equivalents. As a result of the $150 million prepayment of our 2016 Unsecured Senior Bank Term Loan, we recognized a loss on early extinguishment of debt related to the write-off of a portion of unamortized loan fees in June 2013, aggregating $560 thousand.
	4.60% Unsecured senior notes payable
	In February 2012, we completed a $550 million public offering of our unsecured senior notes payable at a stated interest rate of 4.60%. The unsecured senior notes payable were priced at 99.915% of the principal amount with a yield to maturity of 4.61% and are due April 1, 2022. We used the net proceeds of this offering to prepay the outstanding principal balance of $250 million on our unsecured senior bank term loan and to reduce the outstanding borrowings on our unsecured senior line of credit and recognized a loss on early extinguishment of debt of approximately $2.2 million. Refer to the following page for further discussion.
	The unsecured senior notes payable are unsecured obligations of the Company and are fully and unconditionally guaranteed by Alexandria Real Estate Equities, L.P., a 100% owned subsidiary of the Company.  The unsecured senior notes payable rank equally in right of payment with all other senior unsecured indebtedness.  However, the unsecured senior notes payable are subordinate to existing and future mortgages and other secured indebtedness (to the extent of the value of the collateral securing such indebtedness) and to all existing and future preferred equity and liabilities, whether secured or unsecured, of the Company’s subsidiaries, other than Alexandria Real Estate Equities, L.P.
	The requirements of the key financial covenants under our 2.75% Unsecured Senior Notes, 3.90% Unsecured Senior Notes, 4.60% Unsecured Senior Notes, and 4.50% Unsecured Senior Notes as of December 31, 2014, were as follows:
	Debt Covenant Ratios (1)		Requirement
	Total Debt to Total Assets		Less than or equal to 60%
	Secured Debt to Total Assets		Less than or equal to 40%
	Consolidated EBITDA to Interest Expense		Greater than or equal to 1.5x
	Unencumbered Total Asset Value to Unsecured Debt		Greater than or equal to 150%
-1	For definitions of the ratios, refer to the indenture filed as Exhibit 4.3 hereto and the related supplemental indentures filed as Exhibits 4.4, 4.7, 4.9, and 4.11 hereto, which are each listed in Item 15 of this report.
In addition, the terms of the indentures, among other things, limit the ability of the Company, Alexandria Real Estate Equities, L.P., and the Company’s subsidiaries to (i) consummate a merger, or consolidate or sell all or substantially all of the Company’s assets, and (ii) incur certain secured or unsecured indebtedness.
Unsecured senior line of credit and unsecured senior bank term loans
We have unsecured senior bank debt aggregating $1.28 billion as of December 31, 2014, under our 2016 Unsecured Senior Bank Term Loan, 2019 Unsecured Senior Bank Term Loan, and amounts outstanding on our $1.5 billion unsecured senior line of credit. The table below reflects the outstanding balances, maturity dates, applicable rates, and facility fees for each of these facilities.
		Balance as of December 31, 2014				As of December 31, 2014
Facility						Maturity Date (1)		Applicable Rate		Facility Fee
2016 Unsecured Senior Bank Term Loan		$	375	million		Jul-16		L+1.20%		N/A
2019 Unsecured Senior Bank Term Loan		$	600	million		Jan-19		L+1.20%		N/A
$1.5 billion unsecured senior line of credit		$	304	million		Jan-19		L+1.10%		0.20%
-1	Includes any extension options that we control.
During the year ended December 31, 2013, in conjunction with the refinancing of our unsecured senior bank term loans and the partial repayment of $250.0 million of our 2016 Unsecured Senior Bank Term Loan, we recognized a loss on early extinguishment of debt aggregating $2.0 million, related to the write-off of unamortized loan fees.
During the year ended December 31, 2012, we recognized a loss on early extinguishment of debt of approximately $2.2 million, including $1.6 million related to the write-off of unamortized loan fees upon modification of our unsecured senior line of credit and $0.6 million related to the write-off of unamortized loan fees resulting from the prepayment of $250.0 million of our 2012 unsecured senior bank term loan (“2012 Unsecured Senior Bank Term Loan”).
Borrowings under our unsecured senior line of credit will bear interest at a Eurocurrency Rate or a Base Rate specified in the amended unsecured line of credit agreement, plus, in either case, the Applicable Margin. The Eurocurrency Rate specified in the amended unsecured line of credit agreement is, as applicable, the rate per annum equal to (i) the LIBOR or a successor rate thereto as approved by the administrative agent for loans denominated in a LIBOR quoted currency (i.e., U.S. dollars, euro, pounds sterling, or yen), (ii) the average annual yield rates applicable to Canadian dollar banker’s acceptances for loans denominated in Canadian dollars, (iii) the Bank Bill Swap Reference Bid rate for loans denominated in Australian dollars, or (iv) the rate designated with respect to the applicable alternative currency for loans denominated in a non-LIBOR quoted currency (other than Canadian or Australian dollars). The Base Rate specified in the amended unsecured line of credit agreement means for any day a fluctuating rate per annum equal to the highest of (i) the federal funds rate plus 1/2 of 1%, (ii) the rate of interest in effect for such day as publicly announced from time to time by Bank of America as its “prime rate,” and (iii) the Eurocurrency Rate plus 1.00%. The Applicable Margin for LIBOR borrowings under the unsecured senior line of credit as of December 31, 2014, was 1.10%, which is based on our existing credit rating as set by certain rating agencies. As of December 31, 2014, we had $304.0 million in borrowings outstanding on our $1.5 billion unsecured senior line of credit. Our unsecured senior line of credit is subject to an annual facility fee of 0.20% based on the aggregate commitments outstanding.
The requirements of the key financial covenants under our unsecured senior line of credit and unsecured senior bank term loans as of December 31, 2014, were as follows:
Covenant Ratios (1)		Requirement
Leverage Ratio		Less than or equal to 60.0%
Secured Debt Ratio		Less than or equal to 45.0%
Fixed Charge Coverage Ratio		Greater than or equal to 1.50x
Unsecured Leverage Ratio		Less than or equal to 60.0%
Unsecured Interest Coverage Ratio		Greater than or equal to 1.50x
-1	For definitions of the ratios, refer to the amended unsecured senior line of credit and unsecured senior bank term loan agreements filed as Exhibits 10.24, 10.25, 10.26, and 10.27 hereto, which are listed in Item 15 of this report.
In addition, the terms of the unsecured senior line of credit and unsecured senior bank term loan agreements, among other things, limit the ability of the Company, Alexandria Real Estate Equities, L.P., and the Company’s subsidiaries to (i) consummate a merger, or consolidate or sell all or substantially all of the Company’s assets, and (ii) incur certain secured or unsecured indebtedness.  Additionally, the terms of the unsecured senior line of credit and unsecured senior bank term loan agreements include a restriction that may limit our ability to pay dividends, including distributions with respect to common stock or other equity interests, during any time a default is continuing, except to enable us to continue to qualify as a REIT for federal income tax purposes.  As of December 31, 2014, we were in compliance with all such covenants.
The following table summarizes interest expense for the years ended December 31, 2014, 2013, and 2012 (in thousands):
	Year Ended December 31,
	2014				2013				2012
Gross interest	$	126,404			$	128,567			$	131,935
Capitalized interest	(47,105		)		(60,615		)		(62,751		)
Interest expense (1)	$	79,299			$	67,952			$	69,184
(1)    Includes interest expense related to and classified in income from discontinued operations in the accompanying consolidated statements of income.
Repayment of secured note payable
In January 2014, we repaid a $208.7 million secured note payable related to Alexandria Technology Square® that bore interest at a rate of 5.59%. Our joint venture partner funded $20.9 million of the proceeds required to repay the secured note payable. In April 2014, we repaid a $6.4 million secured note payable related to a San Diego property that bore interest at a rate of 4.88%. In August 2014, we repaid a $7.4 million secured note payable related to a San Diego property that bore interest at a rate of 4.00%.
Secured construction loans
The following table summarizes our secured construction loans as of December 31, 2014 (dollars in thousands):
Market		Stated Rate				Maturity Date				Outstanding Balance				Remaining Commitments				Total Aggregate Commitments
San Francisco Bay Area			L+1.50	%		7/1/15		(1)		$	46,792			$	8,208			$	55,000
San Francisco Bay Area			L+1.40	%		6/1/16		(2)		19,343				16,657				36,000
Greater Boston			L+1.35	%		8/23/17		(3)		106,093				144,307				250,400
										$	172,228			$	169,172			$	341,400
-1	We have two, one-year options to extend the stated maturity date to July 1, 2017, subject to certain conditions.
-2	We have two, one-year options to extend the stated maturity date to June 1, 2018, subject to certain conditions.
-3	We have a one-year option to extend the stated maturity date to August 23, 2018, subject to certain conditions.

Interest_rate_swap_agreements_

Interest rate swap agreements (Notes)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest rate swap agreements	Interest rate swap agreements
	We use interest rate swap agreements to hedge the variable cash flows associated with certain of our existing LIBOR-based variable-rate debt, including our unsecured senior line of credit and unsecured senior bank term loans.  The ineffective portion of the change in fair value of our interest rate swap agreements is required to be recognized directly in earnings.  During the years ended December 31, 2014, 2013, and 2012, our interest rate swap agreements were 100% effective; because of this, no hedge ineffectiveness was recognized in earnings.  Changes in fair value, including accrued interest and adjustments for non-performance risk, on the effective portion of our interest rate swap agreements that are designated and that qualify as cash flow hedges are classified in accumulated other comprehensive loss. Amounts classified in accumulated other comprehensive loss are subsequently reclassified into earnings in the period during which the hedged transactions affect earnings.  During the next 12 months, we expect to reclassify approximately $1.1 million in accumulated other comprehensive loss to interest expense as an increase to interest expense. As of December 31, 2014 and 2013, the fair values of our interest rate swap agreements aggregating an asset balance were classified in other assets, and those aggregating a liability balance were classified in accounts payable, accrued expenses, and tenant security deposits, based upon their respective fair values. Under our interest rate swap agreements, we have no collateral posting requirements.
	As of December 31, 2014, the fair value of derivatives in a net liability position was $909 thousand. We have agreements with certain of our derivative counterparties that contain a provision wherein (i) we could be declared in default on our derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to our default on the indebtedness; or (ii) if we default on any of our indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then we could also be declared in default on its derivative obligations. If we had breached any of these provisions as of December 31, 2014, we could have been required to settle our obligations under the agreements at their termination value of $916 thousand.
	We had the following outstanding interest rate swap agreements that were designated as cash flow hedges of interest rate risk as of December 31, 2014 (dollars in thousands):
	Effective Date		Maturity Date	Number of Contracts	Weighted Average Interest Pay	Fair Value as of 12/31/14			Notional Amount in Effect as of
					Rate (1)				12/31/14		12/31/15		12/31/16
	31-Dec-13		31-Mar-15	2	0.23%	$	(43	)	$	250,000	$	—	$	—
	31-Mar-14		31-Mar-15	4	0.21%	(22		)	200,000		—		—
	31-Dec-14		31-Mar-16	3	0.53%	(625		)	500,000		500,000		—
	31-Mar-16		31-Mar-17	3	1.40%	(219		)	—		—		500,000
	Total					$	(909	)	$	950,000	$	500,000	$	500,000
	-1	In addition to the interest pay rate for each swap agreement, interest is also payable at an applicable margin for borrowings outstanding as of December 31, 2014. Borrowings under our unsecured senior bank term loans include an applicable margin of 1.20% and borrowings outstanding under our unsecured senior line of credit include an applicable margin of 1.10%.

Accounts_payable_accrued_expen

Accounts payable, accrued expenses, and tenant security deposits (Notes)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Accounts payable, accrued expenses, and tenant security deposits	Accounts payable, accrued expenses, and tenant security deposits
	The following table summarizes the components of accounts payable, accrued expenses, and tenant security deposits as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014		2013
	Accounts payable and accrued expenses	$	127,828	$	98,037
	Accrued construction	91,110		78,098
	Acquired below market leases	8,810		11,405
	Conditional asset retirement obligations	9,108		7,386
	Deferred rent liability	36,231		35,134
	Interest rate swap liabilities	909		6,191
	Prepaid rent and tenant security deposits	193,699		188,241
	Other liabilities	21,390		10,850
	Total	$	489,085	$	435,342
	Some of our properties may contain asbestos, which, under certain conditions, requires remediation.  Although we believe that the asbestos is appropriately contained in accordance with environmental regulations, our practice is to remediate the asbestos upon the development or redevelopment of the affected property.  We recognize a liability for the fair value of a conditional asset retirement obligation (including asbestos) when the fair value of the liability can be reasonably estimated.  In addition, for certain properties, we have not recognized an asset retirement obligation when there is an indeterminate settlement date for the obligation because the period in which we may remediate the obligation may not be estimated with any level of precision to provide for a meaningful estimate of the retirement obligation. These conditional asset retirement obligations are included in the table above.

Earnings_per_share_Notes

Earnings per share (Notes)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings per share	Earnings per share
	We use income from continuing operations attributable to Alexandria’s common stockholders as the “control number” in determining whether potential common shares are dilutive or antidilutive to EPS.  Pursuant to the presentation and disclosure literature on gains or losses on sales or disposals by REITs and EPS required by the SEC and the FASB, gains or losses on sales or disposals by a REIT that do not qualify as discontinued operations are classified below income from discontinued operations in the consolidated statements of income and included in the numerator for the computation of EPS for income from continuing operations.
	We sold land parcels during the years ended December 31, 2014, 2013, and 2012, that did not meet the criteria for classification as discontinued operations because these land parcels did not have significant operations prior to disposition.  Accordingly, for the years ended December 31, 2014, 2013, and 2012, we classified approximately $6.4 million, $4.8 million, and $1.9 million, respectively, as gain on sales of real estate – land parcels below income from discontinued operations in the accompanying consolidated statements of income, and included the gain in income from continuing operations attributable to Alexandria’s common stockholders in the “control number,” or numerator, for computation of EPS.
	We account for unvested restricted stock awards that contain nonforfeitable rights to dividends as participating securities and include these securities in the computation of EPS using the two-class method.  Our Series D Convertible Preferred Stock is not a participating security, and is not included in the computation of EPS using the two-class method.  Under the two-class method, we allocate net income after preferred stock dividends, preferred stock redemption charge, and amounts attributable to noncontrolling interests to common stockholders and unvested restricted stock awards based on their respective participation rights to dividends declared (or accumulated) and undistributed earnings.  Diluted EPS is computed using the weighted average shares of common stock outstanding determined for the basic EPS computation plus the effect of any dilutive securities, including the dilutive effect of stock options using the treasury stock method and potential common shares issuable upon conversion of our 8.00% unsecured senior convertible notes (“8.00% Unsecured Senior Convertible Notes”), during the period the notes were outstanding.
	The table below is a reconciliation of the numerators and denominators of the basic and diluted EPS computations for the years ended December 31, 2014, 2013, and 2012 (in thousands, except per share amounts):
		Year Ended December 31,
		2014			2013			2012
	Income from continuing operations	$	99,142		$	134,525		$	94,848
	Gain on sales of real estate – land parcels	6,403			4,824			1,864
	Net income attributable to noncontrolling interests	(5,204		)	(4,032		)	(3,402		)
	Dividends on preferred stock	(25,698		)	(25,885		)	(27,328		)
	Preferred stock redemption charge	(1,989		)	—			(5,978		)
	Net income attributable to unvested restricted stock awards	(1,774		)	(1,581		)	(1,190		)
	Income from continuing operations attributable to Alexandria’s common stockholders – basic and diluted	70,880			107,851			58,814
	Income from discontinued operations	1,233			900			8,816
	Net income attributable to Alexandria’s common stockholders – basic and diluted	$	72,113		$	108,751		$	67,630
	Weighted average shares of common stock outstanding – basic and diluted	71,170			68,038			62,160
	EPS attributable to Alexandria’s common stockholders – basic and diluted:
	Continuing operations	$	0.99		$	1.59		$	0.95
	Discontinued operations	0.02			0.01			0.14
	EPS – basic and diluted	$	1.01		$	1.6		$	1.09
	For purposes of calculating diluted EPS, we did not assume conversion of our 8.00% Unsecured Senior Convertible Notes for the years ended December 31, 2013 and 2012, since the impact was antidilutive to EPS attributable to Alexandria’s common stockholders from continuing operations during those periods. We had no 8.00% Unsecured Senior Convertible Notes outstanding during the year ended December 31, 2014.
	For purposes of calculating diluted EPS, we did not assume conversion of our Series D Convertible Preferred Stock for the years ended December 31, 2014, 2013, and 2012, since the impact was antidilutive to EPS attributable to Alexandria’s common stockholders from continuing operations during those periods. Refer to “7.00% Series D Convertible Preferred Stock” in Note 13 – “Stockholders’ Equity” for further discussion of the partial redemption of our Series D Convertible Preferred Stock.

Income_taxes_Notes

Income taxes (Notes)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income taxes	Income taxes
	We are organized and qualify as a REIT pursuant to the Internal Revenue Code. Under the Code, a REIT that distributes at least 90% of its REIT taxable income to its shareholders annually and meets certain other conditions is not subject to federal income taxes, but could be subject to certain state and local taxes. We distribute 100% of our taxable income annually. Therefore, a provision for federal income taxes is not required. In addition to our REIT returns, we file federal, state, and local tax returns for our subsidiaries. We file with jurisdictions located in the U.S., Canada, India, China, and other international locations. Our tax returns are subject to examination in various jurisdictions for the calendar years 2010 through 2013.
	We recognize tax benefits of uncertain tax positions only if it is more likely than not that the tax position will be sustained, based solely on its technical merits, with the taxing authority having full knowledge of all relevant information. The measurement of a tax benefit for an uncertain tax position that meets the “more likely than not” threshold is based on a cumulative probability model under which the largest amount of tax benefit recognized is the amount with a greater than 50% likelihood of being realized upon ultimate settlement with the taxing authority having full knowledge of all the relevant information. As of December 31, 2014, there were no unrecognized tax benefits. We do not anticipate a significant change to the total amount of unrecognized tax benefits within the next 12 months.
	Interest expense and penalties, if any, would be recognized in the first period during which the interest or penalty would begin accruing, according to the provisions of the relevant tax law at the applicable statutory rate of interest. We did not incur any material tax-related interest expense or penalties for the years ended December 31, 2014, 2013, or 2012.
	The following reconciles GAAP net income to taxable income as filed with the IRS for the years ended December 31, 2013 and 2012 (in thousands and unaudited):
			Year ended December 31,
			2013				2012
	Net income		$	140,249			$	105,528
	Net income attributable to noncontrolling interests		(4,032		)		(3,402		)
	Book/tax differences:
	Rental revenue recognition		16,800				11,607
	Depreciation and amortization		12,936				15,501
	Share-based compensation		13,754				11,488
	Interest income (expense)		356				(8,068		)
	Sales of property		(14,284		)		394
	Impairments		—				13,450
	Other		10,284				2,268
	Taxable income, before dividend deduction		176,063				148,766
	Dividend deduction necessary to eliminate taxable income (1)		(176,063		)		(148,766		)
	Estimated income subject to federal income tax		$	—			$	—
	-1	Total common stock and preferred stock dividend distributions paid were approximately $195.0 million and $154.3 million for the years ended December 31, 2013 and 2012, respectively.
	We distributed all of our REIT taxable income in 2013 and 2012, and as a result, did not incur federal income tax in those years on such income. For the year ended December 31, 2014, we expect our distributions to exceed our REIT taxable income, and as a result, do not expect to incur federal income tax on such income. We expect to finalize our 2014 REIT taxable income in connection with our 2014 federal income tax return, which will be prepared and filed with the IRS in 2015.
	The income tax treatment of distributions and dividends declared on our common stock, our Series C Preferred Stock, our Series D Convertible Preferred Stock, and our Series E Preferred Stock for the years ended December 31, 2014, 2013, and 2012, was as follows (unaudited):
		Common Stock											Series C Preferred Stock			Series D Convertible Preferred Stock									Series E Preferred Stock
		Year Ended December 31,
		2014				2013				2012			2012			2014			2013			2012			2014			2013			2012
	Ordinary income	91.8		%		85.9		%		85		%	89.1		%	100		%	97.2		%	89.1		%	100		%	97.2		%	89.1		%
	Return of capital	8.2				11.6				4.6			—			—			—			—			—			—			—
	Capital gains	—				2.5				10.4			10.9			—			2.8			10.9			—			2.8			10.9
	Total	100		%		100		%		100		%	100		%	100		%	100		%	100		%	100		%	100		%	100		%
	Dividends declared	$	2.88			$	2.61			$	2.09		$	0.5234375		$	1.75		$	1.75		$	1.75		$	1.6125		$	1.6125		$	1.34375
	Our tax return for 2014 is due on or before September 15, 2015, assuming we file for an extension of the due date. The taxability information presented for our dividends paid in 2014 is based upon management’s estimate. Our tax returns for previous tax years have not been examined by the IRS. Consequently, the taxability of distributions and dividends is subject to change.

Commitments_and_contingencies_

Commitments and contingencies (Notes)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies
	Employee retirement savings plan
	We have a retirement savings plan pursuant to Section 401(k) of the Internal Revenue Code whereby our employees may contribute a portion of their compensation to their respective retirement accounts in an amount not to exceed the maximum allowed under the Internal Revenue Code. In addition to employee contributions, we have elected to provide company discretionary profit sharing contributions (subject to statutory limitations), which amounted to approximately $1.8 million, $1.6 million, and $1.4 million, for the years ended December 31, 2014, 2013, and 2012, respectively. Employees who participate in the plan are immediately vested in their contributions and in the contributions made on their behalf by the Company.
	Concentration of credit risk
	We maintain our cash and cash equivalents at insured financial institutions. The combined account balances at each institution periodically exceed FDIC insurance coverage of $250,000, and, as a result, there is a concentration of credit risk related to amounts in excess of FDIC insurance coverage. We have not experienced any losses to date on our invested cash.
	In order to limit our risk of non-performance by an individual counterparty under our interest rate swap agreements, we spread our interest rate swap agreements among various counterparties. As of December 31, 2014, the largest aggregate notional amount of interest rate swap agreements in effect at any single point in time with an individual counterparty was $250.0 million. If one or more of our counterparties fail to perform under our interest rate swap agreements, we may incur higher costs associated with our variable-rate LIBOR-based debt than the interest costs we originally anticipated.
	We are dependent on rental income from relatively few client tenants. The inability of any single client tenant to make its lease payments could adversely affect our operations. As of December 31, 2014, we had 562 leases with a total of 441 client tenants, and 87, or 45%, of our 193 properties were each leased to a single client tenant. As of December 31, 2014, our three largest client tenants accounted for approximately 14.6% of our aggregate ABR, or 6.1%, 4.9%, and 3.6%, respectively.
	Commitments
	As of December 31, 2014, remaining aggregate costs under contract for the construction of properties undergoing development, redevelopment, and generic building infrastructure improvements under the terms of leases approximated $525.0 million. We expect payments for these obligations to occur over one to two years, subject to capital planning adjustments from time to time. We may have the ability to cease construction of certain projects resulting in the reduction of our commitments. We are also committed to funding approximately $75.0 million for certain investments over the next several years. We are committed to contribute our 51% share of equity into our joint venture with Uber to complete the development of our 1455/1515 Third Street project. The additional funding commitment as of December 31, 2014 for this joint venture was pending completion of the final design of the building. In addition, we have letters of credit and performance obligations of $13.6 million primarily related to our construction management requirements.
	We have minimum development requirements under project development agreements with government entities for some of our future value-creation projects. As of December 31, 2014, we had land and land improvements with an aggregate book value of $22.1 million for which we had construction commitment obligations aggregating approximately 300,000 RSF and 100,000 RSF that need to be fulfilled by 2016 and 2017, respectively. The estimated cost to develop these projects is approximately $125 to $175 per square foot. If we do not meet, extend, or eliminate these commitments, we may default under our existing agreements. The government entities, in turn, have certain obligations to us under those project development agreements. We are working with these entities to fulfill or amend certain existing obligations in a mutually beneficial manner.
	Rental expense
	Our rental expense attributable to continuing operations for the years ended December 31, 2014, 2013, and 2012, was approximately $13.4 million, $11.4 million, and $10.6 million, respectively. These rental expense amounts include certain operating leases for our headquarters and field offices, and ground leases for 28 of our properties and two land development parcels. Ground leases generally require fixed annual rent payments and may also include escalation clauses and renewal options. Future minimum lease obligations under non-cancelable ground and other operating leases as of December 31, 2014, were as follows (in thousands):
	Year	Office Leases		Ground Leases		Total
	2015	$	1,501	$	9,828	$	11,329
	2016	1,490		10,436		11,926
	2017	1,561		10,506		12,067
	2018	1,632		10,595		12,227
	2019	2,115		8,978		11,093
	Thereafter	—		616,739		616,739
		$	8,299	$	667,082	$	675,381
	Our operating lease obligations related to our office leases have remaining terms of approximately five years, exclusive of extension options. Excluding one ground lease related to one operating property that expires in 2036 with a net book value of approximately $10.0 million as of December 31, 2014, our lease obligations have remaining terms generally ranging from 40 to 100 years, including extension options.

Stockholders_equity_Notes

Stockholders' equity (Notes)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Stockholders' equity	Stockholders’ equity
	7.00% Series D Convertible Preferred Stock
	During the three months ended December 31, 2014, we redeemed 513,500 outstanding shares of our Series D Convertible Preferred Stock at an aggregate price of $14.4 million, or $27.975 per share. We recognized a preferred stock redemption charge of $2.0 million to net income attributable to Alexandria’s common stockholders during the three months ended December 31, 2014, including the write-off of original issuance costs of approximately $412 thousand related to the Series D Convertible Preferred Stock.
	As of December 31, 2014, we had 9.5 million shares of Series D Convertible Preferred Stock outstanding. The dividends on our Series D Convertible Preferred Stock are cumulative and accrue from the date of original issuance. We pay dividends quarterly in arrears at an annual rate of $1.75 per share. Our Series D Convertible Preferred Stock has no stated maturity and is not subject to any sinking fund or mandatory redemption provisions. We are not allowed to redeem our Series D Convertible Preferred Stock, except to preserve our status as a REIT. Investors in our Series D Convertible Preferred Stock generally have no voting rights. We may, at our option, be able to cause some or all of our Series D Convertible Preferred Stock to be automatically converted if the closing sale price per share of our common stock equals or exceeds 150% of the then-applicable conversion price of the Series D Convertible Preferred Stock for at least 20 trading days in a period of 30 consecutive trading days ending on the trading day immediately prior to our issuance of a press release announcing the exercise of our conversion option. Holders of our Series D Convertible Preferred Stock, at their option, may, at any time and from time to time, convert some or all of their outstanding shares initially at a conversion rate of 0.2477 shares of common stock per $25.00 liquidation preference, which was equivalent to an initial conversion price of approximately $100.93 per share of common stock. The conversion rate for the Series D Convertible Preferred Stock is subject to adjustments for certain events, including, but not limited to, certain dividends on our common stock in excess of $0.78 per share per quarter and dividends on our common stock payable in shares of our common stock. As of December 31, 2014, the Series D Convertible Preferred Stock had a conversion rate of approximately 0.2480 shares of common stock per $25.00 liquidation preference, which is equivalent to a conversion price of approximately $100.81 per share of common stock.
	Accumulated other comprehensive loss
	Accumulated other comprehensive loss attributable to Alexandria Real Estate Equities, Inc. consists of the following (in thousands):
		Unrealized Gain on Marketable Securities			Unrealized Loss on Interest Rate			Unrealized Loss on Foreign Currency Translation			Total
					Swap Agreements
	Balance as of December 31, 2013	$	1,590		$	(3,321	)	$	(34,473	)	$	(36,204	)
	Other comprehensive income (loss) before reclassifications	51,135			(4,459		)	(18,075		)	28,601
	Amounts reclassified from other comprehensive (loss) income	(358		)	6,871			(208		)	6,305
	Amounts attributable to noncontrolling interest	—			—			670			670
	Net other comprehensive income (loss)	50,777			2,412			(17,613		)	35,576
	Balance as of December 31, 2014	$	52,367		$	(909	)	$	(52,086	)	$	(628	)
	Preferred stock and excess stock authorizations
	Our charter authorizes the issuance of up to 100.0 million shares of preferred stock, of which 14.7 million shares were issued and outstanding as of December 31, 2014.  In addition, 200.0 million shares of “excess stock” (as defined in our charter) are authorized, none of which were issued and outstanding as of December 31, 2014.

Sharebased_compensation_Notes

Share-based compensation (Notes)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation	Share-based compensation
	Stock plan
	We have a stock option and incentive plan for the purpose of attracting and retaining the highest-quality personnel, providing for additional incentives, and promoting the success of our Company by providing employees the opportunity to acquire common stock pursuant to (i) options to purchase common stock and (ii) share awards. In May 2014, we amended and restated our stock option and incentive plan to increase the number of shares reserved for the granting of awards by 2,800,000 shares and extend the term of the stock plan until May 2024, among other amendments. Each share issued that is subject to a full value award reduces the share reserve by two shares (2:1 ratio); therefore, if we issue only full value awards, the 2,800,000 shares added to the reserve would equate to 1,400,000 awards. As of December 31, 2014, a total of 3,093,382 shares were reserved for the granting of future options and share awards under the stock plan.
	A summary of the stock option activity under our stock plan and related information for the years ended December 31, 2014, 2013, and 2012, follows:
		Number of		Intrinsic Value of Options Exercised
		Stock Options
	Outstanding as of December 31, 2011	3,600
	Granted	—
	Exercised	(3,600	)	$	94,968
	Forfeited	—
	Outstanding as of December 31, 2012	—
	Granted	—
	Outstanding as of December 31, 2013	—
	Granted	—
	Outstanding as of December 31, 2014	—
	In addition, the stock plan permits us to issue share awards to our employees and non-employee directors. A share award is an award of common stock that (i) may be fully vested upon issuance or (ii) may be subject to the risk of forfeiture under Section 83 of the Internal Revenue Code. Shares issued generally vest over a three-year period from the date of issuance, and the sale of the shares is restricted prior to the date of vesting. The unearned portion of these awards is amortized as stock compensation expense on a straight-line basis over the vesting period. Certain restricted share awards are subject to vesting based upon the satisfaction of levels of performance and market conditions. Failure to satisfy the threshold performance conditions will result in the forfeiture of shares. Forfeiture of share awards with time-based or performance-based restrictions results in a reversal of previously recognized share-based compensation expense. Forfeiture of share awards with market-based restrictions does not result in a reversal of previously recognized share-based compensation expense.
	A summary of the share awards activity under our stock plan and related information for the years ended December 31, 2014, 2013, and 2012, follows:
					Number of Share Awards			Weighted Average
								Grant Date
								Fair Value Per Share
	Outstanding as of December 31, 2011				550,763			$		71.04
	Granted				310,240			$		72.85
	Vested				(297,669		)	$		68.52
	Forfeited				(2,266		)	$		74.3
	Outstanding as of December 31, 2012				561,068			$		73.37
	Granted				338,915			$		63.74
	Vested				(323,594		)	$		71.78
	Forfeited				(6,616		)	$		72.96
	Outstanding as of December 31, 2013				569,773			$		68.54
	Granted				416,954			$		72.25
	Vested				(286,681		)	$		72.91
	Forfeited				(25,077		)	$		55.72
	Outstanding as of December 31, 2014				674,969			$		69.46
		Year Ended December 31,
	(In thousands)	2014			2013			2012
	Total fair value of share awards vested	$	20,903		$	23,228		$	20,396
	Total compensation recognized for awards, net of capitalization	$	13,996		$	15,552		$	14,160
	Capitalized stock compensation	$	7,583		$	8,193		$	7,768
	The majority of our restricted share awards contain time-based vesting restrictions and the fair value of these awards is calculated based on the market value of the common stock on the grant date. Certain restricted share awards granted in 2014 contain vesting restrictions based upon the satisfaction of levels of performance and market conditions. The fair value of these awards is determined using a Monte Carlo simulation pricing model, using the following assumptions: expected term of 2.5 years (equal to the remaining performance measurement period at the grant date), volatility of 20.0% (approximating a blended average of implied and historical volatilities), dividend yield of 3.4%, and risk free rate of 0.67%. As of December 31, 2014, there was $39.6 million of unrecognized compensation related to non-vested share awards under the stock plan, which is expected to be recognized over the next three years and has a weighted average vesting period of approximately 14 months.

Noncontrolling_interests_Notes

Noncontrolling interests (Notes)	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Noncontrolling interests	Noncontrolling interests
	Noncontrolling interests represent the third-party interests in certain entities in which we have a controlling interest.  These entities owned four projects as of December 31, 2014, and are included in our consolidated financial statements.  Noncontrolling interests are adjusted for additional contributions and distributions, the proportionate share of the net earnings or losses, and other comprehensive income or loss.  Distributions, profits, and losses related to these entities are allocated in accordance with the respective operating agreements.
	The following table represents income from continuing operations and discontinued operations attributable to Alexandria for the years ended December 31, 2014, 2013, and 2012, excluding the amounts attributable to these noncontrolling interests:
		Year Ended December 31,
		2014		2013		2012
	Income from continuing operations attributable to Alexandria	$	100,341	$	135,317	$	93,310
	Income from discontinued operations	$	1,233	$	900	$	8,816
	Certain of our noncontrolling interests have the right to require us to redeem their ownership interests in the respective entities.  We classify these ownership interests in the entities as redeemable noncontrolling interests outside of total equity in the accompanying consolidated balance sheets.  Redeemable noncontrolling interests are adjusted for additional contributions and distributions, the proportionate share of the net earnings or losses, and other comprehensive income or loss.  Distributions, profits, and losses related to these entities are allocated in accordance with the respective operating agreements.  If the amount of a redeemable noncontrolling interest is less than the maximum redemption value at the balance sheet date, such amount is adjusted to the maximum redemption value.  Subsequent declines in the redemption value are recognized only to the extent that previous increases have been recognized.
	See Note 18 – “Subsequent Events” for our acquisition of the Alexandria Technology Square® noncontrolling interest subsequent to December 31, 2014.

Discontinued_operationsassets_

Discontinued operations/assets held for sale (Notes)	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Discontinued operations	Discontinued Operations/Assets “Held for Sale”
	On October 1, 2014, we adopted an ASU on the reporting of discontinued operations that raised the threshold for classification of assets “held for sale” as discontinued operations. This ASU is applied prospectively, and since our adoption of this ASU, no additional properties met the criteria for classification as a discontinued operation in our consolidated financial statements. Prior to the adoption of this ASU, certain properties met the previous criteria for classification as discontinued operations and are included in the summary of income from discontinued operations below. For additional information, refer to the section titled “Recent Accounting Pronouncements” in Note 2 – “Basis of Presentation and Summary of Significant Accounting Policies” to our audited consolidated financial statements under Item 15 of this Report.
	The following is a summary of net assets “held for sale” as of December 31, 2014 and 2013, including the assets classified as “held for sale” subsequent to our adoption of the new ASU (in thousands):
		As of December 31,
		2014				2013
	Properties “held for sale”	$	173,706			$	7,644
	Other assets	10,147				103
	Total assets	183,853				7,747
	Total liabilities	(6,044		)		(266		)
	Net assets “held for sale” (1)	$	177,809			$	7,481
	-1	As of December 31, 2014, net assets “held for sale” was comprised of the five properties which were “held for sale”, including the two properties subsequently sold in January 2015, and one property classified as “held for sale” and included in discontinued operations prior to the adoption of the ASU.
	The following is a summary of income from discontinued operations related to each asset classified as discontinued operations prior to the adoption of the new ASU on October 1, 2014, for the years ended December 31, 2014, 2013, and 2012, (in thousands):
			Year Ended December 31,
			2014				2013			2012
	Total revenues		$	—			$	4,657		$	36,283
	Operating expenses		(605		)		(1,981		)	(11,313		)
	Total revenues less operating expenses from discontinued operations		(605		)		2,676			24,970
	Depreciation expense		—				(1,655		)	(6,318		)
	Gain (loss) on sales of real estate		1,838				(121		)	1,564
	Impairment of real estate		—				—			(11,400		)
	Income from discontinued operations (1)		$	1,233			$	900		$	8,816
	-1	Income from discontinued operations includes the results of operations of three properties that were disposed of during the year ended December 31, 2014, and the results of one property which was classified as “held for sale” prior to adoption of the new ASU and included as discontinued operations as of December 31, 2014, as well as the results of operations (prior to disposition) and gain (loss) on sale of real estate attributable to 16 properties sold during the period from January 1, 2012, to December 31, 2014.
	The following is a summary of the loss included in our income from continuing operations for the year ended December 31, 2014, from assets classified as “held for sale” subsequent to our adoption of the new ASU (in thousands):
			Year Ended December 31,
			2014				2013			2012
	Total revenues		$	9,661			$	9,975		$	9,604
	Operating expenses		(3,760		)		(3,525		)	(3,156		)
	Total revenues less operating expenses from assets classified as “held for sale”, not qualifying as discontinued operations		5,901				6,450			6,448
	Depreciation expense		(7,005		)		(7,189		)	(7,103		)
	Impairment of real estate		(26,975		)		—			—
	Loss from assets classified as "held for sale", not qualifying as discontinued operations (1)		$	(28,079	)		$	(739	)	$	(655	)
	-1	Includes the results of operations of four properties with an aggregate 1,036,585 RSF that were classified as “held for sale” as of December 31, 2014, but do not qualify for classification as discontinued operations. In January 2015, we subsequently sold two of these properties with an aggregate 802,399 RSF. For additional information, refer to the section titled “Basis of Presentation and Summary of Significant Accounting Policies” in Note 2 to our audited consolidated financial statements under Item 15 of this Report. As of December 31, 2013, and 2012, we did not have any assets classified as “held for sale”, not qualifying as discontinued operations.

Quarterly_financial_data_unaud

Quarterly financial data (unaudited) (Notes)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly financial data (unaudited)	Quarterly financial data (unaudited)
	The following is a summary of consolidated financial information on a quarterly basis for 2014 and 2013 (in thousands, except per share amounts):
			Quarter
	2014		First		Second		Third		Fourth
	Revenues		$	176,186	$	176,402	$	185,615	$	188,674
	Net income (loss) attributable to Alexandria Real Estate Equities, Inc.’s common stockholders		$	32,709	$	27,932	$	27,626	$	(16,154	)
	Earnings per share attributable to Alexandria Real Estate Equities, Inc.’s common stockholders:
	Basic and diluted (1)		$	0.46	$	0.39	$	0.39	$	(0.23	)	(2)
			Quarter
	2013		First		Second		Third		Fourth
	Revenues		$	150,083	$	153,930	$	158,315	$	168,823
	Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders		$	22,442	$	25,483	$	24,579	$	36,247
	Earnings per share attributable to Alexandria Real Estate Equities, Inc.’s common stockholders:
	Basic and diluted (1)		$	0.36	$	0.38	$	0.35	$	0.51
	-1	Quarterly earnings per common share amounts may not total to the annual amounts due to rounding and due to the increase in the weighted average shares of common stock outstanding.
	-2	Results for the fourth quarter of 2014 include an aggregate net loss of $46.2 million, or $0.65 per share, related to impairments of real estate and a preferred stock redemption charge, partially offset by gains on sales of real estate. See further discussion of impairments of real estate and gains on real estate in Note 3 – “Investments in Real Estate.”

Subsequent_events_Notes

Subsequent events (Notes)	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent events	Subsequent events
	Acquisition of 640 Memorial Drive
	In January 2015, we acquired 640 Memorial Drive in the Cambridge submarket for $176.5 million.  This property is a 225,504 RSF Class A, LEED Gold Certified, office/laboratory building located in Mid-Cambridge, nearby the MIT campus, and is 100% leased to two high-quality life science client tenants pursuant to long-term leases. In connection with the acquisition, we assumed a secured note payable of $82.0 million with an interest rate of 3.93% and a maturity date in 2023.  The property is subject to a long-term ground lease.
	Acquisition of Alexandria Technology Square® interest
	In January 2015, we executed an agreement to purchase the outstanding 10% noncontrolling interest in our 1.2 million RSF urban innovation campus at Alexandria Technology Square®. The purchase price of the remaining equity interest was $108.3 million and will be paid in two installments of approximately $54.0 million due on April 1, 2015, and April 1, 2016. The purchase will be accounted for as an equity transaction that will reduce our noncontrolling interest in this campus to zero with the excess purchase price over the noncontrolling interest balance recognized as additional paid-in capital.
	Sale of 661 University Avenue
	In January 2015, we completed the sale of our land and land improvements at 661 University Avenue in Canada for $54.1 million. For additional information, refer to the section titled “Sales of Real Estate Assets and Related Impairment Charges” in Note 3 – “Investments in Real Estate” to our audited consolidated financial statements under Item 15 of this Report.

Condensed_consolidating_financ

Condensed consolidating financial information (Notes)	12 Months Ended
	Dec. 31, 2014
Condensed consolidating financial information
Condensed consolidating financial information	Condensed consolidating financial information
	Alexandria Real Estate Equities, Inc. (the “Issuer”) has sold certain debt securities registered under the Securities Act, as amended, that are fully and unconditionally guaranteed by Alexandria Real Estate Equities, L.P. (the “LP”), an indirectly 100% owned subsidiary of the Issuer. The Company’s other subsidiaries, including, but not limited to, the subsidiaries that own substantially all of its real estate (collectively, the “Combined Non-Guarantor Subsidiaries”) will not provide a guarantee of such securities, including the subsidiaries that are partially or 100% owned by the LP. The following condensed consolidating financial information presents the condensed consolidating balance sheets as of December 31, 2014 and 2013, and the condensed consolidating statements of income, comprehensive income, and cash flows for the years ended December 31, 2014, 2013, and 2012, for the Issuer, the guarantor subsidiary (the LP), the Combined Non-Guarantor Subsidiaries, the eliminations necessary to arrive at the information for Alexandria Real Estate Equities, Inc. on a consolidated basis, and consolidated amounts. In presenting the condensed consolidating financial statements, the equity method of accounting has been applied to (i) the Issuer’s interests in the Guarantor Subsidiary and the Combined Non-Guarantor Subsidiaries, (ii) the Guarantor Subsidiary’s interests in the Combined Non-Guarantor Subsidiaries, and (iii) the Combined Non-Guarantor Subsidiaries’ interests in the Guarantor Subsidiary, where applicable, even though all such subsidiaries meet the requirements to be consolidated under GAAP. All intercompany balances and transactions between the Issuer, the Guarantor Subsidiary, and the Combined Non-Guarantor Subsidiaries have been eliminated, as shown in the column “Eliminations.” All assets and liabilities have been allocated to the Issuer, the Guarantor Subsidiary, and the Combined Non-Guarantor Subsidiaries generally based on legal entity ownership.
	Condensed Consolidating Balance Sheet
	as of December 31, 2014
	(In thousands)
		Alexandria Real Estate Equities, Inc.			Alexandria			Combined			Eliminations			Consolidated
		(Issuer)			Real Estate			Non-
					Equities, L.P.			Guarantor
					(Guarantor			Subsidiaries
					Subsidiary)
	Assets
	Investments in real estate	$	—		$	—		$	7,226,016		$	—		$	7,226,016
	Cash and cash equivalents	52,491			63			33,457			—			86,011
	Restricted cash	67			—			26,817			—			26,884
	Tenant receivables	—			—			10,548			—			10,548
	Deferred rent	—			—			234,124			—			234,124
	Deferred leasing and financing costs	35,462			—			166,336			—			201,798
	Investments	—			5,235			231,154			—			236,389
	Investments in and advances to affiliates	6,874,866			6,295,852			128,943			(13,299,661		)	—
	Other assets	19,461			—			94,805			—			114,266
	Total assets	$	6,982,347		$	6,301,150		$	8,152,200		$	(13,299,661	)	$	8,136,036
	Liabilities, Noncontrolling Interests, and Equity
	Secured notes payable	$	—		$	—		$	652,209		$	—		$	652,209
	Unsecured senior notes payable	1,747,370			—			—			—			1,747,370
	Unsecured senior line of credit	304,000			—			—			—			304,000
	Unsecured senior bank term loans	975,000			—			—			—			975,000
	Accounts payable, accrued expenses, and tenant security deposits	69,013			—			420,072			—			489,085
	Dividends payable	58,525			—			289			—			58,814
	Total liabilities	3,153,908			—			1,072,570			—			4,226,478
	Redeemable noncontrolling interests	—			—			14,315			—			14,315
	Alexandria’s stockholders’ equity	3,828,439			6,301,150			6,998,511			(13,299,661		)	3,828,439
	Noncontrolling interests	—			—			66,804			—			66,804
	Total equity	3,828,439			6,301,150			7,065,315			(13,299,661		)	3,895,243
	Total liabilities, noncontrolling interests, and equity	$	6,982,347		$	6,301,150		$	8,152,200		$	(13,299,661	)	$	8,136,036
	Condensed Consolidating Balance Sheet
	as of December 31, 2013
	(In thousands)
		Alexandria			Alexandria			Combined			Eliminations			Consolidated
		Real Estate			Real Estate			Non-
		Equities, Inc.			Equities, L.P.			Guarantor
		(Issuer)			(Guarantor			Subsidiaries
					Subsidiary)
	Assets
	Investments in real estate	$	—		$	—		$	6,776,914		$	—		$	6,776,914
	Cash and cash equivalents	14,790			—			42,906			—			57,696
	Restricted cash	55			—			27,654			—			27,709
	Tenant receivables	—			—			9,918			—			9,918
	Deferred rent	—			—			190,425			—			190,425
	Deferred leasing and financing costs	36,901			—			155,757			—			192,658
	Investments	—			10,868			129,420			—			140,288
	Investments in and advances to affiliates	6,299,551			5,823,058			119,421			(12,242,030		)	—
	Other assets	20,226			—			113,930			—			134,156
	Total assets	$	6,371,523		$	5,833,926		$	7,566,345		$	(12,242,030	)	$	7,529,764
	Liabilities, Noncontrolling Interests, and Equity
	Secured notes payable	$	—		$	—		$	708,831		$	—		$	708,831
	Unsecured senior notes payable	1,048,230			—			—			—			1,048,230
	Unsecured senior line of credit	204,000			—			—			—			204,000
	Unsecured senior bank term loans	1,100,000			—			—			—			1,100,000
	Accounts payable, accrued expenses, and tenant security deposits	48,373			—			386,969			—			435,342
	Dividends payable	54,131			—			289			—			54,420
	Total liabilities	2,454,734			—			1,096,089			—			3,550,823
	Redeemable noncontrolling interests	—			—			14,444			—			14,444
	Alexandria’s stockholders’ equity	3,916,789			5,833,926			6,408,104			(12,242,030		)	3,916,789
	Noncontrolling interests	—			—			47,708			—			47,708
Total equity	3,916,789			5,833,926			6,455,812			(12,242,030		)	3,964,497
Total liabilities, noncontrolling interests, and equity	$	6,371,523		$	5,833,926		$	7,566,345		$	(12,242,030	)	$	7,529,764
Condensed Consolidating Statement of Income
for the Year Ended December 31, 2014
(In thousands)
	Alexandria			Alexandria			Combined			Eliminations			Consolidated
	Real Estate			Real Estate			Non-
	Equities, Inc.			Equities, L.P.			Guarantor
	(Issuer)			(Guarantor			Subsidiaries
				Subsidiary)
Revenues:
Rental	$	—		$	—		$	544,153		$	—		$	544,153
Tenant recoveries	—			—			173,480			—			173,480
Other income (expense)	12,006			(3,277		)	14,845			(14,330		)	9,244
Total revenues	12,006			(3,277		)	732,478			(14,330		)	726,877
Expenses:
Rental operations	—			—			219,164			—			219,164
General and administrative	45,793			—			22,067			(14,330		)	53,530
Interest	58,159			—			21,140			—			79,299
Depreciation and amortization	5,748			—			218,348			—			224,096
Impairment of real estate	—			—			51,675			—			51,675
Loss on early extinguishment of debt	525			—			—			—			525
Total expenses	110,225			—			532,394			(14,330		)	628,289
Equity in earnings of unconsolidated JVs	—			—			554			—			554
Equity in earnings of affiliates	199,800			188,269			3,665			(391,734		)	—
Income from continuing operations	101,581			184,992			204,303			(391,734		)	99,142
(Loss) income from discontinued operations	(7		)	—			1,240			—			1,233
Gain on sales of real estate – land parcels	—			—			6,403			—			6,403
Net income	101,574			184,992			211,946			(391,734		)	106,778
Dividends on preferred stock	(25,698		)	—			—			—			(25,698		)
Preferred stock redemption charge	(1,989		)	—			—			—			(1,989		)
Net income attributable to noncontrolling interests	—			—			(5,204		)	—			(5,204		)
Net income attributable to unvested restricted stock awards	(1,774		)	—			—			—			(1,774		)
Net income attributable to Alexandria’s common stockholders	$	72,113		$	184,992		$	206,742		$	(391,734	)	$	72,113
Condensed Consolidating Statement of Income
for the Year Ended December 31, 2013
(In thousands)
	Alexandria			Alexandria			Combined			Eliminations			Consolidated
	Real Estate			Real Estate			Non-
	Equities, Inc.			Equities, L.P.			Guarantor
	(Issuer)			(Guarantor			Subsidiaries
				Subsidiary)
Revenues:
Rental	$	—		$	—		$	467,764		$	—		$	467,764
Tenant recoveries	—			—			150,095			—			150,095
Other income (expense)	10,423			(74		)	15,912			(12,969		)	13,292
Total revenues	10,423			(74		)	633,771			(12,969		)	631,151
Expenses:
Rental operations	—			—			189,039			—			189,039
General and administrative	43,528			—			17,961			(12,969		)	48,520
Interest	43,284			—			24,668			—			67,952
Depreciation and amortization	5,907			—			183,216			—			189,123
Loss on early extinguishment of debt	1,992			—			—			—			1,992
Total expenses	94,711			—			414,884			(12,969		)	496,626
Equity in earnings of affiliates	220,158			205,993			4,067			(430,218		)	—
Income from continuing operations	135,870			205,919			222,954			(430,218		)	134,525
Income from discontinued operations	347			—			553			—			900
Gain on sales of real estate – land parcels	—			—			4,824			—			4,824
Net income	136,217			205,919			228,331			(430,218		)	140,249
Dividends on preferred stock	(25,885		)	—			—			—			(25,885		)
Net income attributable to noncontrolling interests	—			—			(4,032		)	—			(4,032		)
Net income attributable to unvested restricted stock awards	(1,581		)	—			—			—			(1,581		)
Net income attributable to Alexandria’s common stockholders	$	108,751		$	205,919		$	224,299		$	(430,218	)	$	108,751
Condensed Consolidating Statement of Income
for the Year Ended December 31, 2012
(In thousands)
	Alexandria			Alexandria			Combined			Eliminations			Consolidated
	Real Estate			Real Estate			Non-
	Equities, Inc.			Equities, L.P.			Guarantor
	(Issuer)			(Guarantor			Subsidiaries
				Subsidiary)
Revenues:
Rental	$	—		$	—		$	422,793		$	—		$	422,793
Tenant recoveries	—			—			133,280			—			133,280
Other income	6,891			1,292			23,294			(13,053		)	18,424
Total revenues	6,891			1,292			579,367			(13,053		)	574,497
Expenses:
Rental operations	—			—			172,756			—			172,756
General and administrative	44,306			3			16,491			(13,053		)	47,747
Interest	46,677			—			22,507			—			69,184
Depreciation and amortization	5,384			—			180,303			—			185,687
Impairment of real estate	—			—			2,050			—			2,050
Loss on early extinguishment of debt	2,225			—			—			—			2,225
Total expenses	98,592			3			394,107			(13,053		)	479,649
Equity in earnings of affiliates	194,566			183,139			3,638			(381,343		)	—
Income from continuing operations	102,865			184,428			188,898			(381,343		)	94,848
(Loss) income from discontinued operations	(739		)	—			9,555			—			8,816
Gain on sales of real estate – land parcels	—			—			1,864			—			1,864
Net income	102,126			184,428			200,317			(381,343		)	105,528
Dividends on preferred stock	(27,328		)	—			—			—			(27,328		)
Preferred stock redemption charge	(5,978		)	—			—			—			(5,978		)
Net income attributable to noncontrolling interests	—			—			(3,402		)	—			(3,402		)
Net income attributable to unvested restricted stock awards	(1,190		)	—			—			—			(1,190		)
Net income attributable to Alexandria’s common stockholders	$	67,630		$	184,428		$	196,915		$	(381,343	)	$	67,630
Condensed Consolidating Statement of Comprehensive Income
for the Year Ended December 31, 2014
(In thousands)
	Alexandria			Alexandria			Combined			Eliminations			Consolidated
	Real Estate			Real Estate			Non-
	Equities, Inc.			Equities, L.P.			Guarantor
	(Issuer)			(Guarantor			Subsidiaries
				Subsidiary)
Net income	$	101,574		$	184,992		$	211,946		$	(391,734	)	$	106,778
Other comprehensive income:
Unrealized gains on marketable securities:
Unrealized holding gains arising during the year	—			148			50,987			—			51,135
Reclassification adjustment for losses (gains) included in net income	—			292			(650		)	—			(358		)
Unrealized gains on marketable securities	—			440			50,337			—			50,777
Unrealized gains on interest rate swap agreements:
Unrealized interest rate swap losses arising during the year	(4,459		)	—			—			—			(4,459		)
Reclassification adjustment for amortization of interest expense included in net income	6,871			—			—			—			6,871
Unrealized gains on interest rate swap agreements	2,412			—			—			—			2,412
Unrealized losses on foreign currency translation:
Unrealized foreign currency translation losses arising during the year	(318		)	—			(17,757		)	—			(18,075		)
Reclassification adjustment for gains included in net income	—			—			(208		)	—			(208		)
Unrealized losses on foreign currency translation	(318		)	—			(17,965		)	—			(18,283		)
Total other comprehensive income	2,094			440			32,372			—			34,906
Comprehensive income	103,668			185,432			244,318			(391,734		)	141,684
Less: comprehensive income attributable to noncontrolling interests	—			—			(4,534		)	—			(4,534		)
Comprehensive income attributable to Alexandria’s common stockholders	$	103,668		$	185,432		$	239,784		$	(391,734	)	$	137,150
Condensed Consolidating Statement of Comprehensive Income
for the Year Ended December 31, 2013
(In thousands)
	Alexandria			Alexandria			Combined			Eliminations			Consolidated
	Real Estate			Real Estate			Non-
	Equities, Inc.			Equities, L.P.			Guarantor
	(Issuer)			(Guarantor			Subsidiaries
				Subsidiary)
Net income	$	136,217		$	205,919		$	228,331		$	(430,218	)	$	140,249
Other comprehensive income (loss):
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the year	—			(438		)	1,738			—			1,300
Reclassification adjustment for losses (gains) included in net income	—			148			(1,331		)	—			(1,183		)
Unrealized (losses) gains on marketable securities	—			(290		)	407			—			117
Unrealized gains on interest rate swap agreements:
Unrealized interest rate swap gains arising during the year	1,918			—			—			—			1,918
Reclassification adjustment for amortization of interest expense included in net income	15,422			—			—			—			15,422
Unrealized gains on interest rate swap agreements	17,340			—			—			—			17,340
Unrealized foreign currency translation losses	—			—			(28,912		)	—			(28,912		)
Total other comprehensive income (loss)	17,340			(290		)	(28,505		)	—			(11,455		)
Comprehensive income	153,557			205,629			199,826			(430,218		)	128,794
Less: comprehensive income attributable to noncontrolling interests	—			—			(3,948		)	—			(3,948		)
Comprehensive income attributable to Alexandria’s common stockholders	$	153,557		$	205,629		$	195,878		$	(430,218	)	$	124,846
Condensed Consolidating Statement of Comprehensive Income
for the Year Ended December 31, 2012
(In thousands)
	Alexandria			Alexandria			Combined			Eliminations			Consolidated
	Real Estate			Real Estate			Non-
	Equities, Inc.			Equities, L.P.			Guarantor
	(Issuer)			(Guarantor			Subsidiaries
				Subsidiary)
Net income	$	102,126		$	184,428		$	200,317		$	(381,343	)	$	105,528
Other comprehensive income:
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the year	—			(319		)	1,309			—			990
Reclassification adjustment for losses (gains) included in net income	—			155			(3,506		)	—			(3,351		)
Unrealized losses on marketable securities	—			(164		)	(2,197		)	—			(2,361		)
Unrealized gains on interest rate swaps:
Unrealized interest rate swap losses arising during the year	(9,990		)	—			—			—			(9,990		)
Reclassification adjustment for amortization of interest expense included in net income	22,309			—			—			—			22,309
Unrealized gains on interest rate swaps	12,319			—			—			—			12,319
Unrealized foreign currency translation losses	—			—			(318		)	—			(318		)
Total other comprehensive income (loss)	12,319			(164		)	(2,515		)	—			9,640
Comprehensive income	114,445			184,264			197,802			(381,343		)	115,168
Less: comprehensive income attributable to noncontrolling interests	—			—			(3,364		)	—			(3,364		)
Comprehensive income attributable to Alexandria’s common stockholders	$	114,445		$	184,264		$	194,438		$	(381,343	)	$	111,804
Condensed Consolidating Statement of Cash Flows
for the Year Ended December 31, 2014
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Operating Activities
Net income	$	101,574		$	184,992		$	211,946		$	(391,734	)	$	106,778
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	5,748			—			218,348			—			224,096
Loss on early extinguishment of debt	525			—			—			—			525
Gain on sales of real estate – rental properties	—			—			(1,838		)	—			(1,838		)
Gain on sales of real estate – land parcels	—			—			(6,403		)	—			(6,403		)
Impairment of real estate	—			—			51,675			—			51,675
Equity in earnings from unconsolidated joint ventures	—			—			(554		)	—			(554		)
Distributions of earnings from unconsolidated joint ventures	—			—			549			—			549
Amortization of loan fees and costs	7,355			—			3,554			—			10,909
Amortization of debt premiums/discounts	232			—			(115		)	—			117
Amortization of acquired below market leases	—			—			(2,845		)	—			(2,845		)
Deferred rent	—			—			(44,726		)	—			(44,726		)
Stock compensation expense	13,996			—			—			—			13,996
Equity in earnings of affiliates	(199,800		)	(188,269		)	(3,665		)	391,734			—
Investment gains	—			—			(11,613		)	—			(11,613		)
Investment losses	—			3,047			6,240			—			9,287
Changes in operating assets and liabilities:
Restricted cash	(12		)	—			4,153			—			4,141
Tenant receivables	—			—			(673		)	—			(673		)
Deferred leasing costs	17			—			(38,299		)	—			(38,282		)
Other assets	(7,785		)	—			319			—			(7,466		)
Accounts payable, accrued expenses, and tenant security deposits	25,877			—			775			—			26,652
Net cash (used in) provided by operating activities	(52,273		)	(230		)	386,828			—			334,325
Investing Activities
Proceeds from sales of real estate	—			—			81,580			—			81,580
Additions to real estate	(65		)	—			(497,708		)	—			(497,773		)
Purchase of real estate	—			—			(127,887		)	—			(127,887		)
Deposits for investing activities	—			—			(10,282		)	—			(10,282		)
Change in restricted cash related to construction projects	—			—			1,665			—			1,665
Investment in unconsolidated joint venture	—			—			(70,758		)	—			(70,758		)
Investments in subsidiaries	(334,764		)	(251,358		)	(13,441		)	599,563			—
Additions to investments	—			(150		)	(60,080		)	—			(60,230		)
Proceeds from sales of investments	—			1,052			17,921			—			18,973
Proceeds from repayment of notes receivable	—			—			29,883			—			29,883
Net cash used in investing activities	$	(334,829	)	$	(250,456	)	$	(649,107	)	$	599,563		$	(634,829	)
Condensed Consolidating Statement of Cash Flows (continued)
for the Year Ended December 31, 2014
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Financing Activities
Borrowings from secured notes payable	$	—		$	—		$	126,215		$	—		$	126,215
Repayments of borrowings from secured notes payable	—			—			(231,051		)	—			(231,051		)
Proceeds from issuance of unsecured senior notes payable	698,908			—			—			—			698,908
Principal borrowings from unsecured senior line of credit	1,168,000			—			—			—			1,168,000
Repayments of borrowings from unsecured senior line of credit	(1,068,000		)	—			—			—			(1,068,000		)
Repayment of unsecured senior bank term loan	(125,000		)	—			—			—			(125,000		)
Redemption of Series D Cumulative Convertible Preferred Stock	(14,414		)	—			—			—			(14,414		)
Transfer to/from parent company	103			250,749			348,711			(599,563		)	—
Change in restricted cash related to financing activities	—			—			(1,409		)	—			(1,409		)
Loan fees and costs paid	(6,523		)	—			(1,576		)	—			(8,099		)
Dividends paid on common stock	(202,386		)	—			—			—			(202,386		)
Dividends paid on preferred stock	(25,885		)	—			—			—			(25,885		)
Distributions to redeemable noncontrolling interests	—			—			(1,191		)	—			(1,191		)
Contributions by noncontrolling interests	—			—			19,410			—			19,410
Distributions to noncontrolling interests	—			—			(3,786		)	—			(3,786		)
Net cash provided by financing activities	424,803			250,749			255,323			(599,563		)	331,312
Effect of foreign exchange rate changes on cash and cash equivalents	—			—			(2,493		)	—			(2,493		)
Net increase (decrease) in cash and cash equivalents	37,701			63			(9,449		)	—			28,315
Cash and cash equivalents at beginning of period	14,790			—			42,906			—			57,696
Cash and cash equivalents at end of period	$	52,491		$	63		$	33,457		$	—		$	86,011
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	$	39,871		$	—		$	18,095		$	—		$	57,966
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	$	—		$	—		$	2,000		$	—		2,000
Change in accrued construction	$	—		$	—		$	29,846		$	—		$	29,846
Assumption of secured notes payable in connection with purchase of properties	$	—		$	—		$	(48,329	)	$	—		$	(48,329	)
Condensed Consolidating Statement of Cash Flows
for the Year Ended December 31, 2013
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Operating Activities
Net income	$	136,217		$	205,919		$	228,331		$	(430,218	)	$	140,249
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	5,907			—			184,871			—			190,778
Loss on early extinguishment of debt	1,992			—			—			—			1,992
Gain on sales of real estate – land parcels	—			—			(4,824		)	—			(4,824		)
Loss on sales of real estate – rental properties	—			—			121			—			121
Amortization of loan fees and costs	6,914			—			3,022			—			9,936
Amortization of debt premiums/discounts	111			—			418			—			529
Amortization of acquired below market leases	—			—			(3,316		)	—			(3,316		)
Deferred rent	(82		)	—			(27,853		)	—			(27,935		)
Stock compensation expense	15,552			—			—			—			15,552
Equity in earnings of affiliates	(220,158		)	(205,993		)	(4,067		)	430,218			—
Investment gains	—			(3		)	(7,047		)	—			(7,050		)
Investment losses	—			78			1,402			—			1,480
Changes in operating assets and liabilities:
Restricted cash	(2		)	—			901			—			899
Tenant receivables	—			—			(1,519		)	—			(1,519		)
Deferred leasing costs	(37		)	—			(54,788		)	—			(54,825		)
Other assets	(5,606		)	—			(692		)	—			(6,298		)
Intercompany receivables and payables	3,021			—			(3,021		)	—			—
Accounts payable, accrued expenses, and tenant security deposits	(13,485		)	—			70,443			—			56,958
Net cash (used in) provided by operating activities	(69,656		)	1			382,382			—			312,727
Investing Activities
Proceeds from sale of real estate	10,796			—			143,172			—			153,968
Additions to real estate	—			—			(593,389		)	—			(593,389		)
Purchase of real estate	—			—			(122,069		)	—			(122,069		)
Change in restricted cash related to construction projects	—			—			7,655			—			7,655
Investment in unconsolidated joint venture	—			—			(17,987		)	—			(17,987		)
Investments in subsidiaries	(236,218		)	(276,022		)	(13,445		)	525,685			—
Additions to investments	—			—			(36,078		)	—			(36,078		)
Proceeds from sales of investments	—			1,018			15,507			—			16,525
Net cash used in investing activities	$	(225,422	)	$	(275,004	)	$	(616,634	)	$	525,685		$	(591,375	)
Condensed Consolidating Statement of Cash Flows (continued)
for the Year Ended December 31, 2013
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Financing Activities
Borrowings from secured notes payable	$	—		$	—		$	28,489		$	—		$	28,489
Repayments of borrowings from secured notes payable	—			—			(36,219		)	—			(36,219		)
Proceeds from issuance of senior notes payable	498,561			—			—			—			498,561
Principal borrowings from unsecured senior line of credit	729,000			—			—			—			729,000
Repayments of borrowings from unsecured senior line of credit	(1,091,000		)	—			—			—			(1,091,000		)
Repayments of unsecured senior bank term loans	(250,000		)	—			—			—			(250,000		)
Repurchase of unsecured senior convertible notes	(384		)	—			—			—			(384		)
Transfer to/from parent company	—			273,089			252,596			(525,685		)	—
Change in restricted cash related to financing activities	(1		)	—			2,547			—			2,546
Loan fees and costs paid	(14,383		)	—			(5,545		)	—			(19,928		)
Proceeds from common stock offerings	534,469			—			—			—			534,469
Dividends paid on common stock	(169,076		)	—			—			—			(169,076		)
Dividends paid on preferred stock	(25,885		)	—			—			—			(25,885		)
Distributions to redeemable noncontrolling interests	—			—			(1,191		)	—			(1,191		)
Distributions to noncontrolling interests	—			—			(1,812		)	—			(1,812		)
Net cash provided by financing activities	211,301			273,089			238,865			(525,685		)	197,570
Effect of foreign exchange rate changes on cash and cash equivalents	—			—			(2,197		)	—			(2,197		)
Net (decrease) increase in cash and cash equivalents	(83,777		)	(1,914		)	2,416			—			(83,275		)
Cash and cash equivalents at beginning of period	98,567			1,914			40,490			—			140,971
Cash and cash equivalents at end of period	$	14,790		$	—		$	42,906		$	—		$	57,696
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	$	37,073		$	—		$	22,784		$	—		$	59,857
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	$	29,820		$	—		$	9,000		$	—		$	38,820
Change in accrued construction	$	—		$	—		$	(21,310	)	$	—		$	(21,310	)
Condensed Consolidating Statement of Cash Flows
for the Year Ended December 31, 2012
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Operating Activities
Net income	$	102,126		$	184,428		$	200,317		$	(381,343	)	$	105,528
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,490			—			185,515			—			192,005
Loss on early extinguishment of debt	2,225			—			—			—			2,225
Gain on sales of real estate – rental properties	—			—			(1,564		)	—			(1,564		)
Gain on sales of real estate – land parcels	—			—			(1,864		)	—			(1,864		)
Impairment of real estate	6,400			—			7,050			—			13,450
Amortization of loan fees and costs	9,204			—			628			—			9,832
Amortization of debt premiums/discounts	114			—			397			—			511
Amortization of acquired above and below market leases	—			—			(3,200		)	—			(3,200		)
Deferred rent	(224		)	—			(28,232		)	—			(28,456		)
Equity in earnings of affiliates	(194,566		)	(183,139		)	(3,638		)	381,343			—
Stock compensation expense	14,160			—			—			—			14,160
Investment gains	—			(1,510		)	(13,508		)	—			(15,018		)
Investment losses	—			221			2,416			—			2,637
Changes in operating assets and liabilities:
Restricted cash	(12		)	—			(249		)	—			(261		)
Tenant receivables	11			—			(992		)	—			(981		)
Deferred leasing costs	(305		)	—			(44,794		)	—			(45,099		)
Other assets	1,329			—			(5,398		)	—			(4,069		)
Intercompany receivables and payables	(826		)	—			826			—			—
Accounts payable, accrued expenses, and tenant security deposits	6,172			—			59,525			—			65,697
Net cash (used in) provided by operating activities	(47,702		)	—			353,235			—			305,533
Investing Activities
Proceeds from sales of real estate	—			—			36,179			—			36,179
Additions to real estate	(1,313		)	—			(547,717		)	—			(549,030		)
Purchase of real estate	—			—			(42,171		)	—			(42,171		)
Change in restricted cash related to construction projects	—			—			(9,377		)	—			(9,377		)
Investment in unconsolidated joint venture	—			—			(6,700		)	—			(6,700		)
Distributions from unconsolidated joint venture	—			—			22,250			—			22,250
Investments in subsidiaries	(197,665		)	(158,022		)	(1,179		)	356,866			—
Additions to investments	—			(353		)	(35,941		)	—			(36,294		)
Proceeds from sales of investments	—			2,600			24,443			—			27,043
Net cash used in investing activities	$	(198,978	)	$	(155,775	)	$	(560,213	)	$	356,866		$	(558,100	)
Condensed Consolidating Statement of Cash Flows (continued)
for the Year Ended December 31, 2012
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Financing Activities
Borrowings from secured notes payable	$	—		$	—		$	17,810		$	—		$	17,810
Repayments of borrowings from secured notes payable	—			—			(26,367		)	—			(26,367		)
Proceeds from issuance of unsecured senior notes payable	544,650			—			—			—			544,650
Principal borrowings from unsecured senior line of credit	847,147			—			—			—			847,147
Repayments of borrowings from unsecured senior line of credit	(651,147		)	—			—			—			(651,147		)
Repayments of unsecured senior bank term loan	(250,000		)	—			—			—			(250,000		)
Repurchase of unsecured senior convertible notes	(84,801		)	—			—			—			(84,801		)
Redemption of Series C Cumulative Redeemable Preferred Stock	(129,638		)	—			—			—			(129,638		)
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock	124,868			—			—			—			124,868
Transfer to/from parent company	—			157,689			199,177			(356,866		)	—
Change in restricted cash related to financing activities	—			—			(7,428		)	—			(7,428		)
Loan fees and costs paid	(10,180		)	—			(3,045		)	—			(13,225		)
Proceeds from common stock offerings	97,890			—			—			—			97,890
Proceeds from exercise of stock options	155			—			—			—			155
Dividends paid on common stock	(126,498		)	—			—			—			(126,498		)
Dividends paid on preferred stock	(27,819		)	—			—			—			(27,819		)
Distributions to redeemable noncontrolling interests	—			—			(1,249		)	—			(1,249		)
Redemption of redeemable noncontrolling interests	12			—			(462		)	—			(450		)
Contributions by noncontrolling interests	—			—			1,875			—			1,875
Distributions to noncontrolling interests	—			—			(913		)	—			(913		)
Net cash provided by financing activities	334,639			157,689			179,398			(356,866		)	314,860
Effect of foreign exchange rate changes on cash and cash equivalents	—			—			139			—			139
Net increase (decrease) in cash and cash equivalents	87,959			1,914			(27,441		)	—			$	62,432
Cash and cash equivalents at beginning of period	10,608			—			67,931			—			$	78,539
Cash and cash equivalents at end of period	$	98,567		$	1,914		$	40,490		$	—		$	140,971
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	$	39,298		$	—		$	13,263		$	—		$	52,561
Non-Cash Investing Activities
Note receivable from sale of real estate	$	—		$	—		$	6,125		$	—		$	6,125
Write-off of fully amortized improvements	$	—		$	—		$	(17,730	)	$	—		$	(17,730	)
Change in accrued construction	$	(2,000	)	$	—		$	48,087		$	—		$	46,087

Schedule_III_Consolidated_Fina

Schedule III - Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation (Notes)	12 Months Ended
	Dec. 31, 2014
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation	Schedule III
	Consolidated Financial Statement Schedule of Real Estate and Accumulated Depreciation
	31-Dec-14
	(In thousands)
									Initial Costs						Costs Capitalized Subsequent to Acquisitions		Total Costs
	Property		Market		Encumbrances				Land				Buildings & Improvements		Buildings & Improvements		Land		Buildings & Improvements		Total (1)		Accumulated Depreciation (2)			Net Cost Basis		Date of Construction (3)	Date
																													Acquired
	Alexandria Center® at Kendall Square		Greater Boston		$	106,093			$	280,713			$	199,583	$	662,031	$	280,713	$	861,614	$	1,142,327	$	(44,490	)	$	1,097,837	2000-2013	2005-2013
	Alexandria Technology Square®		Greater Boston		—				—				619,658		186,472		—		806,130		806,130		(141,360		)	664,770		2001-2012	2006
	480 Arsenal Street		Greater Boston		—				6,413				5,457		46,115		6,413		51,572		57,985		(14,358		)	43,627		2003	2001
	780/790 Memorial Drive		Greater Boston		—				—				—		45,140		—		45,140		45,140		(17,895		)	27,245		2002	2001
	500 Arsenal Street		Greater Boston		—				3,360				7,316		29,136		3,360		36,452		39,812		(13,368		)	26,444		2001	2000
	167 Sidney Street/99 Erie Street		Greater Boston		—				—				12,613		12,273		—		24,886		24,886		(4,064		)	20,822		2006/2012	2005/2006
	79/96 Thirteenth Street Charlestown Navy Yard		Greater Boston		4,556			(4)	—				6,247		8,661		—		14,908		14,908		(2,785		)	12,123		2012	1998
	Alexandria Park at 128		Greater Boston		23,301			(4) (5)	10,439				41,596		56,059		10,439		97,655		108,094		(27,003		)	81,091		1997-2010	1998-2008
	225 Second Avenue		Greater Boston		—				2,925				14,913		17,047		2,925		31,960		34,885		—			34,885		2014	2014
	19 Presidential Way		Greater Boston		—				12,833				27,333		66		12,833		27,399		40,232		(6,621		)	33,611		1999	2005
	100 Beaver Street		Greater Boston		—				1,466				9,046		11,742		1,466		20,788		22,254		(4,169		)	18,085		2006	2005
	285 Bear Hill Road		Greater Boston		—				422				3,538		5,189		422		8,727		9,149		(340		)	8,809		2013	2011
	111/130 Forbes Boulevard		Greater Boston		—				3,146				15,725		2,936		3,146		18,661		21,807		(3,940		)	17,867		2006	2007/2006
	20 Walkup Drive		Greater Boston		—				2,261				7,099		9,029		2,261		16,128		18,389		(1,639		)	16,750		2012	2006
	306 Belmont Street & 350 Plantation Street		Greater Boston		—				1,806				11,696		1,783		1,806		13,479		15,285		(3,594		)	11,691		2003	2004
	30 Bearfoot Road		Greater Boston		—				1,220				22,375		44		1,220		22,419		23,639		(5,512		)	18,127		2000	2005
	Alexandria Center® for Science & Technology		San Francisco Bay Area		—				93,813				210,211		370,840		93,813		581,051		674,864		(53,840		)	621,024		2007-2011	2004-2011
	Alexandria Technology Center – Gateway		San Francisco Bay Area		98,133			(6)	45,425				121,059		15,378		45,425		136,437		181,862		(35,125		)	146,737		2000-2006	2002-2006
	249/259/269 East Grand Avenue		San Francisco Bay Area		66,135				19,396				—		151,275		19,396		151,275		170,671		(14,070		)	156,601		2008/2012/2014	2004
	400/450 East Jamie Court		San Francisco Bay Area		—				—				—		109,622		—		109,622		109,622		(15,612		)	94,010		2012	2002
	500 Forbes Boulevard		San Francisco Bay Area		—				35,596				69,091		14,441		35,596		83,532		119,128		(16,450		)	102,678		2001	2007
	7000 Shoreline Court		San Francisco Bay Area		31,234			(6)	7,038				39,704		9,070		7,038		48,774		55,812		(11,684		)	44,128		2001	2004
	341/343 Oyster Point Boulevard		San Francisco Bay Area		—				7,038				—		31,968		7,038		31,968		39,006		(13,517		)	25,489		2009/2013	2000
	849/863 Mitten Road & 866 Malcolm Road		San Francisco Bay Area		—				3,211				8,665		15,307		3,211		23,972		27,183		(8,139		)	19,044		2012	1998
	2425 Garcia Avenue & 2400/2450 Bayshore Parkway		San Francisco Bay Area		830				1,512				21,323		25,150		1,512		46,473		47,985		(16,339		)	31,646		2008	1999
	3165 Porter Drive		San Francisco Bay Area		20,421			(5)	—				19,154		2,105		—		21,259		21,259		(5,686		)	15,573		2002	2003
	75/125 Shoreway Road		San Francisco Bay Area		—				6,617				7,091		10,852		6,617		17,943		24,560		(3,069		)	21,491		2008	2006
	3350 West Bayshore Road		San Francisco Bay Area		—				4,800				6,693		10,940		4,800		17,633		22,433		(3,486		)	18,947		1982	2005
									Initial Costs						Costs Capitalized Subsequent to Acquisitions		Total Costs
	Property		Market		Encumbrances				Land				Buildings & Improvements		Buildings & Improvements		Land		Buildings & Improvements		Total (1)		Accumulated Depreciation (2)			Net Cost Basis		Date of Construction (3)	Date
																													Acquired
	2625/2627/2631 Hanover Street		San Francisco Bay Area		$	—			$	—			$	6,628	$	10,488	$	—	$	17,116	$	17,116	$	(7,440	)	$	9,676	2000	1999
	510 Townsend Street		San Francisco Bay Area		—				52,105				—		6,354		52,105		6,354		58,459		—			58,459		N/A	2014
	560 Eccles Avenue		San Francisco Bay Area		—				12,093				—		5,562		12,093		5,562		17,655		(3		)	17,652		N/A	2006
	Grand Avenue		San Francisco Bay Area		—				37,538				—		7,518		37,538		7,518		45,056		(21		)	45,035		N/A	2004/2005/2008
	Alexandria Center® for Life Science		New York City		—				—				—		778,293		—		778,293		778,293		(47,615		)	730,678		2010-2013	2006
	100 Phillips Parkway		New York City		9,353			(4)	1,840				2,298		14,897		1,840		17,195		19,035		(7,917		)	11,118		1999	1998
	102 Witmer Road		New York City		—				1,625				19,715		5,641		1,625		25,356		26,981		(6,279		)	20,702		2002	2006
	701 Veterans Circle		New York City		—				1,468				7,885		26		1,468		7,911		9,379		(1,485		)	7,894		2007	2007
	5100 Campus Drive		New York City		—				256				2,117		469		256		2,586		2,842		(1,254		)	1,588		1989	1998
	ARE Nautilus		San Diego		—				6,684				27,600		83,309		6,684		110,909		117,593		(24,872		)	92,721		2010-2012	1994-1997
	ARE Sunrise		San Diego		19,590			(7)	2,954				15,491		41,518		2,954		57,009		59,963		(29,960		)	30,003		2000-2009	1994-2000
	ARE Spectrum		San Diego		—				27,388				80,957		46,944		27,388		127,901		155,289		(15,905		)	139,384		2008	2007
	11119 North Torrey Pines Road		San Diego		—				9,994				37,099		32,505		9,994		69,604		79,598		(6,188		)	73,410		2012	2007
	3545 Cray Court		San Diego		39,387				7,056				53,944		—		7,056		53,944		61,000		(4,864		)	56,136		1998	2014
	5200 Illumina Way		San Diego		—				38,340				96,606		73,541		38,340		170,147		208,487		(15,176		)	193,311		2004-2014	2010
	10300 Campus Point Drive		San Diego		—				22,487				90,198		102,464		22,487		192,662		215,149		(12,655		)	202,494		2012	2010
	ARE Esplanade		San Diego		11,452			(7)	9,682				29,991		45,439		9,682		75,430		85,112		(9,459		)	75,653		1989-2013	1998-2011
	ARE Towne Centre		San Diego		34,110			(5)	8,539				18,850		40,293		8,539		59,143		67,682		(31,899		)	35,783		2000-2010	1999
	9880 Campus Point Drive		San Diego		—				3,823				16,165		20,053		3,823		36,218		40,041		(8,915		)	31,126		2005	2001
	5810/5820/6138/6150 Nancy Ridge Drive		San Diego		11,435			(5)	5,476				28,682		1,811		5,476		30,493		35,969		(7,743		)	28,226		2000-2001	2003-2004
	ARE Portola		San Diego		—				6,991				25,153		17,734		6,991		42,887		49,878		(4,905		)	44,973		2005-2012	2007
	10121/10151 Barnes Canyon Road		San Diego		—				4,608				5,100		14,257		4,608		19,357		23,965		(188		)	23,777		1988	2013
	7330 Carroll Road		San Diego		4,517			(4)	2,650				19,878		1,253		2,650		21,131		23,781		(2,347		)	21,434		2007	2010
	5871 Oberlin Drive		San Diego		—				1,349				8,016		3,623		1,349		11,639		12,988		(949		)	12,039		2004	2010
	6146 Nancy Ridge Road		San Diego		—				515				1,566		2,844		515		4,410		4,925		(2,183		)	2,742		2001	2000
	11025/11035/11045/11055/11065/		San Diego		—				4,156				11,571		22,161		4,156		33,732		37,888		(5,828		)	32,060		2006/2008/2014	1997/2000/2014
11075 Roselle Street
3985/4025/4031/4045 Sorrento Valley Boulevard		San Diego		7,333			(8)	4,323				22,846		3,568		4,323		26,414		30,737		(2,651		)	28,086		2007	2010/2014
13112 Evening Creek Drive		San Diego		12,398			(7)	7,393				27,950		150		7,393		28,100		35,493		(5,504		)	29,989		2007	2007
1201/1208 Eastlake Avenue East		Seattle		41,830			(7)	5,810				47,149		14,955		5,810		62,104		67,914		(18,941		)	48,973		1997	2002
1616 Eastlake Avenue East		Seattle		—				6,940				—		82,526		6,940		82,526		89,466		(17,874		)	71,592		2013	2003
1551 Eastlake Avenue East		Seattle		—				8,525				20,064		32,893		8,525		52,957		61,482		(6,055		)	55,427		2012	2004
199 East Blaine Street		Seattle		—				6,528				—		71,707		6,528		71,707		78,235		(9,980		)	68,255		2010	2004
219 Terry Avenue North		Seattle		—				1,819				2,302		18,943		1,819		21,245		23,064		(1,705		)	21,359		2012	2007
1600 Fairview Avenue East		Seattle		—				2,212				6,788		6,009		2,212		12,797		15,009		(2,611		)	12,398		2007	2005
3000/3018 Western Avenue		Seattle		—				1,432				7,497		21,590		1,432		29,087		30,519		(7,528		)	22,991		2000	1998
								Initial Costs						Costs Capitalized Subsequent to Acquisitions		Total Costs
Property		Market		Encumbrances				Land				Buildings & Improvements		Buildings & Improvements		Land		Buildings & Improvements		Total (1)		Accumulated Depreciation (2)			Net Cost Basis		Date of Construction (3)	Date
																												Acquired
410 West Harrison/410 Elliott Avenue West		Seattle		$	—			$	3,857			$	1,989	$	10,549	$	3,857	$	12,538	$	16,395	$	(2,604	)	$	13,791	2008/2006	2004
9800 Medical Center Drive		Maryland		76,000				10,052				99,696		96,305		10,052		196,001		206,053		(40,359		)	165,694		2010-2013	2004
1330 Piccard Drive		Maryland		—				2,800				11,533		28,928		2,800		40,461		43,261		(12,517		)	30,744		2005	1997
1500/1550 East Gude Drive		Maryland		—				1,523				7,731		5,511		1,523		13,242		14,765		(4,919		)	9,846		2003/1995	1997
14920/15010 Broschart Road		Maryland		5,804			(9)	4,904				15,846		3,823		4,904		19,669		24,573		(3,152		)	21,421		1998/1999	2010/2004
1405 Research Boulevard		Maryland		—				899				21,946		11,515		899		33,461		34,360		(10,165		)	24,195		2006	1997
5 Research Place		Maryland		—				1,466				5,708		27,007		1,466		32,715		34,181		(6,427		)	27,754		2010	2001
9920 Medical Center Drive		Maryland		—				5,791				8,060		1,071		5,791		9,131		14,922		(2,141		)	12,781		2002	2004
5 Research Court		Maryland		—				1,647				13,258		5,199		1,647		18,457		20,104		(13,489		)	6,615		2007	2004
12301 Parklawn Drive		Maryland		—				1,476				7,267		561		1,476		7,828		9,304		(1,912		)	7,392		2007	2004
Alexandria Technology Center – Gaithersburg I		Maryland		—				10,183				59,641		21,652		10,183		81,293		91,476		(22,561		)	68,915		1992-2009	1997-2004
Alexandria Technology Center – Gaithersburg II		Maryland		—				4,531				21,594		31,651		4,531		53,245		57,776		(21,028		)	36,748		2000-2003	1997-2000
16020 Industrial Drive		Maryland		—				2,924				19,664		714		2,924		20,378		23,302		(9,349		)	13,953		1983	2005
401 Professional Drive		Maryland		—				1,129				6,941		5,745		1,129		12,686		13,815		(4,603		)	9,212		2007	1996
950 Wind River Lane		Maryland		—				2,400				10,620		1,050		2,400		11,670		14,070		(1,557		)	12,513		2009	2010
620 Professional Drive		Maryland		—				784				4,705		7,216		784		11,921		12,705		(1,320		)	11,385		2012	2005
8000/9000/10000 Virginia Manor Road		Maryland		—				—				13,679		5,847		—		19,526		19,526		(7,765		)	11,761		2003	1998
14225 Newbrook Drive		Maryland		28,297			(7)	4,800				27,639		6,863		4,800		34,502		39,302		(12,542		)	26,760		2006	1997
Alexandria Technology Center – Alston		Research Triangle Park		—				1,430				17,482		27,781		1,430		45,263		46,693		(17,701		)	28,992		1985-2009	1998
108/110/112/114 TW Alexander Drive		Research Triangle Park		—				—				376		42,050		—		42,426		42,426		(11,837		)	30,589		2000	1999
Alexandria Innovation Center – Research Triangle Park		Research Triangle Park		—				1,065				21,218		24,461		1,065		45,679		46,744		(11,144		)	35,600		2005-2008	2000
6 Davis Drive		Research Triangle Park		—				9,920				10,712		7,573		9,920		18,285		28,205		(3,623		)	24,582		2012	2012
7 Triangle Drive		Research Triangle Park		—				701				—		31,643		701		31,643		32,344		(2,914		)	29,430		2011	2005
407 Davis Drive		Research Triangle Park		—				1,229				17,733		—		1,229		17,733		18,962		(683		)	18,279		1998	2013
2525 East NC Highway 54		Research Triangle Park		—				713				12,827		894		713		13,721		14,434		(3,685		)	10,749		1995	2004
601 Keystone Park Drive		Research Triangle Park		—				785				11,546		5,017		785		16,563		17,348		(3,140		)	14,208		2009	2006
5 Triangle Drive		Research Triangle Park		—				161				3,409		2,857		161		6,266		6,427		(2,074		)	4,353		1981	1998
6101 Quadrangle Drive		Research Triangle Park		—				951				3,982		9,462		951		13,444		14,395		(1,221		)	13,174		2012	2008
555 Heritage Drive		Research Triangle Park		—				2,919				5,311		11,959		2,919		17,270		20,189		(2,461		)	17,728		2010	2006
								Initial Costs						Costs Capitalized Subsequent to Acquisitions		Total Costs
Property		Market		Encumbrances				Land				Buildings & Improvements		Buildings & Improvements		Land		Buildings & Improvements		Total (1)		Accumulated Depreciation (2)			Net Cost Basis		Date of Construction (3)	Date
																												Acquired
661 University Ave (10)		Canada		$	—			$	—			$	—	$	63,511	$	—	$	63,511	$	63,511	$	(12,016	)	$	51,495	2008	2007
1781 W. 75th Avenue		Canada		—				2,059				4,244		8,482		2,059		12,726		14,785		(2,235		)	12,550		2008	2007
7990 Enterprise Street		Canada		—				2,277				8,864		—		2,277		8,864		11,141		(1,979		)	9,162		2003	2005
245/275 Armand Frappier		Canada		—				6,986				23,043		6,477		6,986		29,520		36,506		(5,529		)	30,977		2012	2005
525 Cartier Boulevard West		Canada		—				2,926				18,746		—		2,926		18,746		21,672		(4,604		)	17,068		2004	2005
China		Asia		—				—				—		85,845		—		85,845		85,845		(3,625		)	82,220		Various	2011
India		Asia		—				32,433				—		139,726		32,433		139,726		172,159		(5,746		)	166,413		Various	2009-2012
Various		Various		—				64,032				27,141		266,062		64,032		293,203		357,235		(28,564		)	328,671		Various	Various
				$	652,209			$	1,057,802			$	2,791,443	$	4,497,016	$	1,057,802	$	7,288,459	$	8,346,261	$	(1,120,245	)	$	7,226,016
-1	The aggregate cost of real estate for federal income tax purposes is not materially different from the cost basis under GAAP (unaudited).
-2	The depreciable life for buildings and improvements ranges from 30 to 40 years, 20 for land improvements, and the term of the respective lease for tenant improvement.
-3	Represents the later of the date of original construction or the date of the latest renovation.
-4	Loan of $30,377 secured by four properties identified by this reference.
-5	Loan of $77,316 secured by six properties identified by this reference.
-6	Loan of $129,367 secured by four properties identified by this reference.
-7	Loan of $113,567 secured by six properties identified by this reference.
-8	The balance shown includes an unamortized premium of $242.
-9	The balance shown includes an unamortized premium of $27.
-10	Represents land and land improvements in Toronto, Canada that were classified in rental properties. This real estate was leased to a tenant and the tenant was completing the construction of a 780,540 RSF building. In December 2014, we determined that this property met the criteria to be classified as “held for sale”. In January 2015, we completed the sale.
Alexandria Real Estate Equities, Inc.
Consolidated Financial Statement Schedule of Real Estate and Accumulated Depreciation
31-Dec-14
(In thousands)
A summary of activity of consolidated real estate and accumulated depreciation is as follows:
		December 31,
Rental Properties		2014				2013				2012
Balance at beginning of period		$	6,442,208			$	5,645,771			$	5,112,759
Purchase of rental properties		95,400				118,892				42,901
Sale of rental properties		(7,541		)		(182,037		)		(30,807		)
Write-off of fully amortized improvements		—				—				(17,730		)
Transfers from current, near-term and future value-creation projects		458,246				859,582				538,648
Balance at end of period		$	6,988,313			$	6,442,208			$	5,645,771
		December 31,
Current, Near-Term and Future Value-Creation Projects		2014				2013				2012
Balance at beginning of period		$	1,286,812			$	1,653,842			$	1,638,216
Acquisitions		69,944				11,422				—
Sales of land		(94,581		)		(67,880		)		(14,655		)
Transfers to rental properties		(458,246		)		(859,582		)		(538,648		)
Change in unconsolidated real estate joint venture		70,762				17,988				(13,686		)
Additions to current, near-term and future value-creation projects		483,257				531,022				582,615
Balance at end of period		$	1,357,948			$	1,286,812			$	1,653,842
		December 31,
Accumulated Depreciation		2014				2013				2012
Balance at beginning of period		$	952,106			$	875,035			$	742,535
Depreciation expense on properties		183,432				149,848				157,193
Write-off of fully amortized improvements		—				—				(17,730		)
Sale of properties		(15,293		)		(72,777		)		(6,963		)
Balance at end of period		$	1,120,245			$	952,106			$	875,035

Basis_of_presentation_and_summ1

Basis of presentation and summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recent accounting pronouncements	Recent accounting pronouncements
	In April 2014, the FASB issued an ASU on the reporting of discontinued operations that raised the threshold for classification of assets “held for sale” as discontinued operations. Under this ASU, a discontinued operation is (i) a component of an entity or group of components that has been disposed of by sale, that has been disposed of other than by sale, or that is classified as “held for sale” and represents a strategic shift that has had or will have a major effect on an entity’s operations and financial results or (ii) an acquired business or non-profit activity that is classified as “held for sale” on the date of the acquisition. A strategic shift that has or will have a major effect on an entity’s operations and financial results could include the disposal of (i) a major line of business, (ii) a major geographic area, (iii) a major equity method investment, or (iv) other major parts of an entity. The ASU also allows for an entity to report a discontinued operation if it has certain continuing cash flows or involvement with the component after the disposal. We adopted this ASU on October 1, 2014. This ASU requires prospective application and since our adoption, no additional real estate met the criteria for classification as discontinued operations in our consolidated financial statements. The adoption of the ASU did not impact assets classified as discontinued operations prior to the adoption.
Basis of presentation and consolidation	Basis of presentation and consolidation
	The accompanying consolidated financial statements include the accounts of Alexandria and its consolidated subsidiaries. All significant intercompany balances and transactions have been eliminated.
	In certain circumstances, we may enter into joint venture arrangements with outside partners. On a quarterly basis, we evaluate each joint venture arrangement under the VIE model, and if the entity is determined not to be a VIE, then we evaluate the entity under the voting model to determine if the entity should be consolidated.
	Under the VIE model, an entity is determined to be a VIE if it has any of the following characteristics:
	•	The entity does not have sufficient equity to finance its activities without additional subordinated financial support;
	•	The equity holders, as a group, lack the characteristics of a controlling financial interest; or
	•	The legal entity is established with non-substantive voting rights.
	If an entity is determined to be a VIE, we evaluate whether or not we are the primary beneficiary using qualitative analyses. Factors considered include, but are not limited to, the purpose and design of the VIE, risks that the VIE was designed to create and pass through, the form of our ownership interest, our representation on the entity’s governing body, the size and seniority of our investment, our ability to participate in policy-making decisions, and the rights of the other investors to participate in the decision-making process and/or liquidate the venture, if applicable. We consolidate VIEs whenever we determine that we are the primary beneficiary.
	If an entity is determined not to be a VIE, we then evaluate such entity under the voting model. Under the voting model, if we are the general partner or managing member, or have a similar role that can direct the operations of the entity, we have a presumption that we control the entity and we should consolidate regardless of our ownership percentage. If we determine that the other equity holders have any one of the following rights, it is assumed that we do not control the entity and therefore should not consolidate the entity: (i) the substantive ability to dissolve the entity or remove us from the lead role of the entity, or (ii) substantive rights that allow them to participate in the activities that most significantly impact the entity’s economic performance.
	As of December 31, 2014, we had two joint ventures that did not meet the requirements for consolidation and were accounted for under the equity method of accounting. Refer to Note 3 – “Investments in Real Estate,” appearing elsewhere in this annual report on Form 10-K, for further information on our unconsolidated joint ventures.
Use of estimates	Use of estimates
	The preparation of consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, and equity; the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements; and the amounts of revenues and expenses during the reporting period.  Actual results could materially differ from those estimates.
Operating segment	Operating segment
	We are engaged in the business of providing office/laboratory and tech office space for lease to the science and technology industries. Our properties are similar in that they provide space for lease to the science and technology industries, consist of improvements that are generic and reusable for the science and technology industries, are primarily located in urban innovation cluster submarkets, and have similar economic characteristics. Our chief operating decision maker reviews financial information for our entire consolidated operations when making decisions on how to allocate resources and in assessing our operating performance or individual properties when determining real estate decisions. The financial information disclosed herein represents all of the financial information related to our principal operating segment.
International operations	International operations
	The functional currency for our subsidiaries operating in the U.S. is the U.S. dollar. We have five properties in Canada, two properties in China, seven operating properties in India, and various land parcels in India. The functional currencies for our foreign subsidiaries are the local currencies in each respective country. The assets and liabilities of our foreign subsidiaries are translated into U.S. dollars at the exchange rate in effect as of the financial statement date. Income statement accounts of our foreign subsidiaries are translated using the average exchange rate for the periods presented. Gains or losses resulting from the translation are classified in accumulated other comprehensive loss as a separate component of total equity.
	The appropriate amounts of foreign exchange rate gains or losses classified in accumulated other comprehensive loss will be reflected in our consolidated statements of income when there is a sale or partial sale of our investment in these operations or upon a complete or substantially complete liquidation of the investment.
Investments in real estate, net, and discontinued operations	Investments in real estate and properties classified as “held for sale”
	We recognize real estate acquired (including the intangible value of above or below market leases, acquired in-place leases, client tenant relationships, and other intangible assets or liabilities), liabilities assumed, and any noncontrolling interest in an acquired entity at their fair value as of the acquisition date.  If there is a bargain fixed-rate renewal option for the period beyond the non-cancelable lease term of an in-place lease, we evaluate factors such as the business conditions in the industry in which the lessee operates, the economic conditions in the area in which the property is located, and the ability of the lessee to sublease the property during the renewal term, in order to determine the likelihood that the lessee will renew.  When we determine there is reasonable assurance that such bargain purchase option will be exercised, we consider its impact in determining the intangible value of such lease and its related amortization period.  The value of tangible assets acquired is based upon our estimation of value on an “as if vacant” basis.  The value of acquired in-place leases includes the estimated costs during the hypothetical lease-up period and other costs that would have been incurred in the execution of similar leases, considering market conditions at the acquisition date of the acquired in-place lease.  We assess the fair value of tangible and intangible assets based on numerous factors, including estimated cash flow projections that utilize appropriate discount and capitalization rates and available market information.  Estimates of future cash flows are based on a number of factors, including the historical operating results, known trends, and market/economic conditions that may affect the property.  We also recognize the fair values of assets acquired, the liabilities assumed, and any noncontrolling interest in acquisitions of less than a 100% interest when the acquisition constitutes a change in control of the acquired entity.  Acquisition-related costs related to the acquisition of businesses, including real estate acquired with in-place leases, are expensed as incurred.
	The values allocated to buildings and building improvements, land improvements, tenant improvements, and equipment are depreciated on a straight-line basis using the shorter of the term of the respective ground lease and up to 40 years for buildings and building improvements, an estimated life of 20 years for land improvements, the respective lease term for tenant improvements, and the estimated useful life for equipment. The values of acquired above and below market leases are amortized over the terms of the related leases and recognized as either an increase (for below market leases) or a decrease (for above market leases) to rental income. The values of acquired in-place leases are classified in other assets in the accompanying consolidated balance sheets, and amortized over the remaining terms of the related leases.
	We are required to capitalize project costs, including predevelopment costs, interest, property taxes, insurance, and other costs directly related and essential to the development, redevelopment, predevelopment, or construction of a project.  Capitalization of development, redevelopment, and construction costs is required while activities are ongoing to prepare an asset for its intended use.  Fluctuations in our development, redevelopment, and construction activities could result in significant changes to total expenses and net income.  Costs incurred after a project is substantially complete and ready for its intended use are expensed as incurred.  Should development, redevelopment, or construction activity cease, interest, property taxes, insurance, and certain other costs would no longer be eligible for capitalization and would be expensed as incurred.  Expenditures for repairs and maintenance are expensed as incurred.
	A property is classified as “held for sale” when all of the following criteria for a plan of sale have been met: (i) management, having the authority to approve the action, commits to a plan to sell the property; (ii) the property is available for immediate sale in its present condition, subject only to terms that are usual and customary; (iii) an active program to locate a buyer and other actions required to complete the plan to sell have been initiated; (iv) the sale of the property is probable and is expected to be completed within one year; (v) the property is being actively marketed for sale at a price that is reasonable in relation to its current fair value; and (vi) actions necessary to complete the plan of sale indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Depreciation of assets ceases upon designation of a property as “held for sale.” Prior to adoption of the new discontinued ASU mentioned above, the operations of properties “held for sale” were classified as discontinued operations in our consolidated statements of income, and amounts for all prior periods presented were reclassified from continuing operations to discontinued operations.
	Subsequent to the adoption of the new discontinued operations ASU mentioned above, if the disposal of the property represents a strategic shift that has (or will have) a major effect on our operations or financial results, such as (i) a major line of business, (ii) a major geographic area, (iii) a major equity method investment, or (iv) other major parts of an entity, then the operations of the property “held for sale,” including any interest expense directly attributable to it, are classified as discontinued operations in our consolidated statements of income, and amounts for all prior periods presented are reclassified from continuing operations to discontinued operations. The disposal of an individual property generally will not represent a strategic shift and therefore not meet the criteria for classification as discontinued operations.
Impairment of long-lived assets	Impairment of long-lived assets
	Long-lived assets to be held and used, including our rental properties, CIP, land held for development, and intangibles, are individually evaluated for impairment when conditions exist that may indicate that the amount of a long-lived asset may not be recoverable.  The amount of a long-lived asset to be held and used is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset.  Impairment indicators or triggering events for long-lived assets to be held and used, including our rental properties, CIP, and land held for development, are assessed by project and include significant fluctuations in estimated revenue less rental operating expense, occupancy changes, significant near-term lease expirations, current and historical operating and/or cash flow losses, construction costs, estimated completion dates, rental rates, and other market factors.  We assess the expected undiscounted cash flows based upon numerous factors, including, but not limited to, construction costs, available market information, current and historical operating results, known trends, current market/economic conditions that may affect the property, and our assumptions about the use of the asset, including, if necessary, a probability-weighted approach if multiple outcomes are under consideration.  Upon determination that an impairment has occurred, a write-down is recognized to reduce the carrying amount to its estimated fair value.  If an impairment loss is not required to be recognized, the recognition of depreciation is adjusted prospectively, as necessary, to reduce the carrying amount of the real estate to its estimated disposition value over the remaining period that the real estate is expected to be held and used.  We may adjust depreciation of properties that are expected to be disposed of or redeveloped prior to the end of their useful lives.
	We use the “held for sale” impairment model for our properties classified as “held for sale.”  The “held for sale” impairment model is different from the held and used impairment model.  Under the “held for sale” impairment model, an impairment loss is recognized if the amount of the long-lived asset classified as “held for sale” exceeds its fair value less cost to sell.  Because of these two different models, it is possible for a long-lived asset previously classified as held and used to require the recognition of an impairment charge upon classification as “held for sale.”
Cash and cash equivalents	Cash and cash equivalents
	We consider all highly liquid investments with original maturities of three months or less when purchased to be cash and cash equivalents. The majority of our cash and cash equivalents are held at major commercial banks in accounts that may at times exceed the FDIC-insured limit of $250,000. We have not experienced any losses to date on our invested cash.
Restricted cash	Restricted cash
	Restricted cash primarily consists of funds held in trust under the terms of our secured bank loans, funds held in escrow related to construction projects, and funds held for various other deposits.
Investments	Investments
	We hold equity investments in certain publicly traded companies and investments in certain privately held entities and limited partnerships primarily involved in the science and technology industries.  All of our investments in actively traded public companies are considered “available for sale” and are reflected in the accompanying consolidated balance sheets at fair value.  Fair value has been determined based upon the closing price as of each balance sheet date, with unrealized gains and losses shown as a separate component of comprehensive income.  The classification of each investment is determined at the time each investment is made, and such determination is reevaluated at each balance sheet date.  The cost of each investment sold is determined by the specific identification method, with realized gains or losses classified in other income in the accompanying consolidated statements of income.  Investments in privately held entities are generally accounted for under the cost method when our interest in the entity is so minor that we have virtually no influence over the entity’s operating and financial policies. Certain investments in privately held entities are accounted for under the equity method unless our interest in the entity is deemed to be so minor that we have virtually no influence over the entity’s operating and financial policies. Under the equity method of accounting, we recognize our investment initially at cost and adjust the amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment.  Additionally, we limit our ownership percentage in the voting stock of each individual entity to less than 10%.  As of December 31, 2014 and 2013, our ownership percentage in the voting stock of each individual entity was less than 10%.
	We monitor each of our equity investments throughout the year for new developments, including operating results, results of clinical trials, capital-raising events, and merger and acquisition activities. Individual investments are evaluated for impairment when changes in conditions may indicate an impairment exists.  The factors that we consider in making these assessments include, but are not limited to, market prices, market conditions, available financing, prospects for favorable or unfavorable clinical trial results, new product initiatives, and new collaborative agreements.  If there are no identified events or changes in circumstances that might have an adverse effect on our cost method investments, we do not estimate the investment’s fair value.  For all of our investments, if a decline in the fair value of an investment below the carrying value is determined to be other than temporary, such investment is written down to its estimated fair value with a charge to current earnings.
Leasing costs	Leasing costs
	Costs directly related and essential to our leasing activities are capitalized and amortized on a straight-line basis over the term of the related lease. Costs related to unsuccessful leasing opportunities are expensed.
Loan fees and costs	Loan fees and costs
	Fees and costs incurred in obtaining long-term financing are capitalized. Capitalized amounts are amortized over the term of the related loan, and the amortization is classified in interest expense in the accompanying consolidated statements of income.
Interest rate swap agreements	Interest rate swap agreements
	We are exposed to certain risks arising from both our business operations and economic conditions. We principally manage our exposures to a wide variety of business and operational risks through management of our core business activities. We manage economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of our debt funding and the use of interest rate swap agreements. Specifically, we enter into interest rate swap agreements to manage exposures that arise from business activities that result in the payment of future known and uncertain cash amounts, the values of which are determined by interest rates. Our interest rate swap agreements are used to manage differences in the amount, timing, and duration of our known or expected cash payments principally related to our borrowings based on LIBOR. We do not use derivatives for trading or speculative purposes, and currently all of our derivatives are designated as hedges. Our objectives in using interest rate swap agreements are to add stability to interest expense and to manage our exposure to interest rate movements in accordance with our interest rate risk management strategy. All of our interest rate swaps are designated as cash flow hedges. Interest rate swap agreements designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the interest rate swap agreements without exchange of the underlying notional amount of interest rate swap agreements.
	We utilize interest rate swap agreements to hedge a portion of our exposure to variable interest rates primarily associated with borrowings based on LIBOR. We recognize our interest rate swap agreements as either assets or liabilities on the balance sheet at fair value.  The accounting for changes in fair value (i.e., gains or losses) of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and, further, on the type of hedging relationship. For those derivative instruments that are designated and qualify as hedging instruments, a company must designate the hedging instrument, based on the hedged exposure, as a fair value hedge, a cash flow hedge, or a hedge of a net investment in a foreign operation. Our interest rate swap agreements are considered cash flow hedges because they are designated and qualify as hedges of the exposure to variability in expected future cash flows. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the earnings effect of the hedged transactions in a cash flow hedge. All of our interest rate swap agreements meet the criteria to be deemed “highly effective” in reducing our exposure to variable interest rates. We formally document all relationships between interest rate swap agreements and hedged items, including the method for evaluating effectiveness and the risk strategy. We make an assessment at the inception of each interest rate swap agreement and on an ongoing basis to determine whether these instruments are “highly effective” in offsetting changes in cash flows associated with the hedged items. The ineffective portion of each interest rate swap agreement is immediately recognized in earnings. While we intend to continue to meet the conditions for such hedge accounting, if swaps did not qualify as “highly effective,” the changes in the fair values of the derivatives used as hedges would be reflected in earnings.
	The effective portion of changes in the fair value of our interest rate swap agreements that are designated and that qualify as cash flow hedges is recognized in accumulated other comprehensive income. Amounts classified in accumulated other comprehensive income will be reclassified into earnings in the period during which the hedged transactions affect earnings.
	The fair value of each interest rate swap agreement is determined using widely accepted valuation techniques including discounted cash flow analyses on the expected cash flows of each derivative. These analyses reflect the contractual terms of the derivatives, including the period to maturity, and use observable market-based inputs, including interest rate curves and implied volatilities. The fair values of our interest rate swap agreements are determined using the market standard methodology of netting the discounted future fixed cash payments and the discounted expected variable cash receipts. The variable cash receipts are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves. The fair value calculation also includes an amount for risk of non-performance of our counterparties using “significant unobservable inputs” such as estimates of current credit spreads to evaluate the likelihood of default, which we have determined to be insignificant to the overall fair value of our interest rate swap agreements.
Recognition of rental income and tenant recoveries	Recognition of rental income and tenant recoveries
	Rental income from leases is recognized on a straight-line basis over the respective lease terms.  We classify amounts currently recognized as income, and expected to be received in later years, as deferred rent in the accompanying consolidated balance sheets.  Amounts received currently, but recognized as income in future years, are classified in accounts payable, accrued expenses, and tenant security deposits in the accompanying consolidated balance sheets.  We commence recognition of rental income at the date the property is ready for its intended use and the client tenant takes possession of or controls the physical use of the property.
	Tenant recoveries related to reimbursement of real estate taxes, insurance, utilities, repairs and maintenance, common area expenses, and other operating expenses are recognized as revenue in the period during which the applicable expenses are incurred.
	Tenant receivables consist primarily of amounts due for contractual lease payments, reimbursements of common area maintenance expenses, property taxes, and other expenses recoverable from client tenants.  Tenant receivables are expected to be collected within one year.  We may maintain an allowance for estimated losses that may result from the inability of our client tenants to make payments required under the terms of the lease and for tenant recoveries due.  If a client tenant fails to make contractual payments beyond any allowance, we may recognize additional bad debt expense in future periods equal to the amount of uncollectible rent and deferred rent receivables arising from the straight-lining of rent.  As of December 31, 2014 and 2013, we had no allowance for estimated losses.
Monitoring client tenant credit quality	Monitoring client tenant credit quality
	During the term of each lease, we monitor the credit quality of our client tenants by (i) reviewing the credit rating of client tenants that are rated by a nationally recognized credit rating agency, (ii) reviewing financial statements of the client tenants that are publicly available or that are required to be delivered to us pursuant to the applicable lease, (iii) monitoring news reports regarding our client tenants and their respective businesses, and (iv) monitoring the timeliness of lease payments. We have a team of employees who, among them, have graduate and undergraduate degrees in biology, chemistry, and industrial biotechnology and experience in the science and technology industries, as well as in finance. Our research team is responsible for assessing and monitoring the credit quality of our client tenants and any material changes in credit quality.
Interest income	Interest income
	Interest income was approximately $4.2 million, $4.6 million, and $3.4 million during the years ended December 31, 2014, 2013, and 2012, respectively.  Interest income is included in other income in the accompanying consolidated statements of income.
Stock-based compensation expense	Share-based compensation expense
	We have historically issued two forms of share-based compensation under our equity incentive plan: options to purchase common stock (“options”) and restricted share awards. We have not granted any options since 2002. We recognize all share-based compensation in the income statement based on the grant date fair value. Compensation expense is recognized on a straight-line basis over the period during which the employee is required to provide services in exchange for the award (the vesting period). We recognize share-based compensation based on awards that are ultimately expected to vest. As a result, future forfeitures of awards are estimated at the time of grant and revised in subsequent periods, as necessary, if actual forfeitures differ from those estimates. In most cases, no compensation cost is recognized for equity instruments that are forfeited or are anticipated to be forfeited. The majority of our restricted share awards contain time-based vesting restrictions and the fair value of these awards is calculated based on the market value of the common stock on the grant date. Certain restricted share awards contain vesting restrictions based upon the satisfaction of levels of performance and market conditions. The fair value of these awards is determined using a Monte Carlo simulation pricing model. Failure to satisfy the threshold performance and/or market conditions will result in the forfeiture of shares. Forfeiture of share awards with time-based or performance-based restrictions results in a reversal of previously recognized share-based compensation expense. Forfeiture of share awards with market-based restrictions does not result in a reversal of previously recognized share-based compensation expense.

Background_Tables

Background (Tables)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of rentable square feet by property	Our asset base consisted of the following, as of December 31, 2014:
		Square Feet
		(unaudited)
	Operating properties	16,727,985
	Development properties (includes unconsolidated JVs)	1,857,520
	Redevelopment properties	143,777
	Total operating and current value-creation projects	18,729,282
	Near-term value-creation projects in North America (CIP)	2,715,792
	Future value-creation projects	10,093,396
		12,809,188
	Total	31,538,470

Investments_in_real_estate_Tab

Investments in real estate (Tables)	12 Months Ended
	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Investments in real estate	Our investments in real estate consisted of the following as of December 31, 2014 and 2013 (in thousands):
		31-Dec-14			31-Dec-13
	Land (related to rental properties)	$	624,681		$	553,388
	Buildings and building improvements	6,171,504			5,714,673
	Other improvements	192,128			174,147
	Rental properties	6,988,313			6,442,208
	CIP/current value-creation projects:
	Current development in North America	500,894			511,838
	Current redevelopment in North America	42,482			8,856
	Current development in Asia	14,065			60,928
		557,441			581,622
	Near-term value-creation projects in North America (CIP):
	50, 60, and 100 Binney Street	321,907			284,672
	Other projects	107,471			97,617
		429,378			382,289
	Future value-creation projects:
	North America	175,175			176,063
	Asia	78,548			77,251
		253,723			253,314
	Land under sales contract	—			22,943
	Near-term and future value-creation projects	683,101			658,546
	Gross investments in real estate	8,228,855			7,682,376
	Equity method of accounting – unconsolidated joint ventures	117,406			46,644
	Gross investments in real estate – including unconsolidated joint ventures	8,346,261			7,729,020
	Less: accumulated depreciation	(1,120,245		)	(952,106		)
	Investments in real estate	$	7,226,016		$	6,776,914
Schedule of future minimum lease payments	Minimum lease payments to be received under the terms of the operating lease agreements, excluding expense reimbursements, in effect as of December 31, 2014, are outlined in the table below (in thousands):
	Year	Amount
	2015	$	496,797
	2016	488,626
	2017	466,829
	2018	423,234
	2019	373,509
	Thereafter	1,995,904
	Total	$	4,244,899
Acquired-in-Place Leases
Finite-Lived Intangible Assets [Line Items]
Schedule of above and below market leases, net of related amortization	The balances of acquired in-place leases, and related accumulated amortization, are classified in other assets in the accompanying consolidated balance sheets. As of December 31, 2014 and 2013, these amounts were as follows (in thousands):
		31-Dec-14			31-Dec-13
	Acquired in-place leases	$	51,395		$	48,189
	Accumulated amortization	(32,123		)	(28,927		)
		$	19,272		$	19,262
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	The estimated annual amortization of the value of acquired in-place leases is as follows (in thousands):
	Year	Amount
	2015	$	3,663
	2016	2,709
	2017	2,513
	2018	2,377
	2019	2,095
	Thereafter	5,915
	Total	$	19,272
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Schedule of above and below market leases, net of related amortization	The balances of acquired below market leases, and related accumulated amortization, classified in accounts payable, accrued expenses, and tenant security deposits in the accompanying consolidated balance sheets as of December 31, 2014 and 2013, were as follows (in thousands):
		31-Dec-14			31-Dec-13
	Acquired below market leases	$	55,955		$	55,599
	Accumulated amortization	(47,145		)	(44,194		)
		$	8,810		$	11,405
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	The estimated annual amortization of the value of acquired below market leases is as follows (in thousands):
	Year	Amount
	2015	$	2,861
	2016	2,455
	2017	2,251
	2018	705
	2019	209
	Thereafter	329
	Total	$	8,810

Deferred_leasing_and_financing1

Deferred leasing and financing costs (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of deferred leasing and financing costs	The following table summarizes our deferred leasing and financing costs, as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014			2013
	Deferred leasing costs	$	333,109		$	293,879
	Accumulated amortization	(174,194		)	(146,881		)
		158,915			146,998
	Deferred financing costs	126,687			118,078
	Accumulated amortization	(83,804		)	(72,418		)
		42,883			45,660
	Deferred leasing and financing costs	$	201,798		$	192,658

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Investments [Abstract]
Summary of investments	The following table summarizes our investments as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014			2013
	“Available-for-sale” marketable equity securities, at cost basis	$	21,898		$	2,879
	Unrealized gains	53,625			2,177
	Unrealized losses	(1,258		)	(587		)
	“Available-for-sale” marketable equity securities, at fair value	74,265			4,469
	Investments accounted for under cost method	162,124			135,819
	Investments	$	236,389		$	140,288
Schedule of net investment income	The following table outlines our investment income, which is classified in other income in the accompanying consolidated statements of income (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Investment gains	$	11,613		$	7,050		$	15,018
	Investment losses	(9,287		)	(1,480		)	(2,637		)
	Investment income	$	2,326		$	5,570		$	12,381

Fair_value_measurements_Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Schedule of fair value of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy	The following tables set forth the assets and liabilities that we measure at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2014 and 2013 (in thousands):
						31-Dec-14
	Description		Total			Quoted Prices in			Significant			Significant
						Active Markets			Other			Unobservable
						for Identical			Observable			Inputs
						Assets			Inputs
	Assets:
	“Available-for-sale securities”		$	74,265		$	74,265		$	—		$	—
	Liabilities:
	Interest rate swap agreements		$	909		$	—		$	909		$	—
						31-Dec-13
	Description		Total			Quoted Prices in			Significant			Significant
						Active Markets			Other			Unobservable
						for Identical			Observable			Inputs
						Assets			Inputs
	Assets:
	“Available-for-sale securities”		$	4,469		$	4,469		$	—		$	—
	Interest rate swap agreements		$	2,870		$	—		$	2,870		$	—
	Liabilities:
	Interest rate swap agreements		$	6,191		$	—		$	6,191		$	—
Schedule of the book and fair values of our marketable securities, interest rate swap agreements, secured notes payable, unsecured senior notes payable, unsecured senior line of credit, and unsecured senior bank term loan	As of December 31, 2014 and 2013, the book and estimated fair values of our marketable equity securities, interest rate swap agreements, secured notes payable, unsecured senior notes payable, unsecured senior line of credit, and unsecured senior bank term loans were as follows (in thousands):
		31-Dec-14						31-Dec-13
		Book Value			Fair Value			Book Value			Fair Value
	Assets:
	Marketable equity securities	$	74,265		$	74,265		$	4,469		$	4,469
	Interest rate swap agreements	$	—		$	—		$	2,870		$	2,870
	Liabilities:
	Interest rate swap agreements	$	909		$	909		$	6,191		$	6,191
	Secured notes payable	$	652,209		$	693,338		$	708,831		$	736,772
	Unsecured senior notes payable	$	1,747,370		$	1,793,255		$	1,048,230		$	1,043,125
	Unsecured senior line of credit	$	304,000		$	304,369		$	204,000		$	193,714
	Unsecured senior bank term loans	$	975,000		$	976,010		$	1,100,000		$	1,099,897

Secured_and_unsecured_senior_d1

Secured and unsecured senior debt (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Summary of secured and unsecured debt	The following table summarizes our secured and unsecured senior debt as of December 31, 2014 (dollars in thousands):
		Fixed Rate/Hedged				Unhedged				Total				Percentage of Total Debt			Weighted Average			Weighted Average
		Variable Rate				Variable Rate				Consolidated							Interest Rate at			Remaining Term
																	End of Period (1)			(in years)
	Secured notes payable	$	403,981			$	248,228			$	652,209			17.7	%		4.59	%		2.7
	Unsecured senior notes payable	1,747,370				—				1,747,370				47.5			3.98			8.3
	$1.5 billion unsecured senior line of credit	—				304,000				304,000				8.3			1.27			4
	2016 Unsecured Senior Bank Term Loan	350,000				25,000				375,000				10.2			1.42			1.6
	2019 Unsecured Senior Bank Term Loan	600,000				—				600,000				16.3			1.67			4
	Total/weighted average	$	3,101,351			$	577,228			$	3,678,579			100	%		3.23	%		5.6
	Percentage of total debt	84%				16%				100%
	-1	Represents the weighted average interest rate as of the end of the period plus the impact of debt premiums/discounts and our interest rate swap agreements. The weighted average interest rate excludes bank fees and amortization of loan fees.
Summary of fixed rate/hedged and unhedged floating rate debt and their respective principal maturities	The following table summarizes our outstanding indebtedness and respective principal maturities as of
	December 31, 2014 (dollars in thousands):
			Stated			Weighted Average			Maturity Date(2)		Principal Payments Remaining for the Period Ending December 31,
	Debt		Rate			Interest Rate(1)					2015				2016				2017			2018			2019			Thereafter			Total
	Secured notes payable
	Maryland		5.64	%		4.5	%		6/1/15		$	5,777			$	—			$	—		$	—		$	—		$	—		$	5,777
	San Francisco Bay Area		L+1.50			1.66			7/1/15		46,792				—				—			—			—			—			46,792
	Greater Boston, San Francisco Bay Area, and San Diego		5.73			5.73			1/1/16		1,815				75,501				—			—			—			—			77,316
	Greater Boston, San Diego, and New York City		5.82			5.82			4/1/16		988				29,389				—			—			—			—			30,377
	San Diego		5.74			3			4/15/16		175				6,916				—			—			—			—			7,091
	San Francisco Bay Area		L+1.40			1.56			6/1/16		—				19,343				—			—			—			—			19,343
	San Francisco Bay Area		6.35			6.35			8/1/16		2,652				126,715				—			—			—			—			129,367
	Maryland		2.15			2.15			1/20/17		—				—				76,000			—			—			—			76,000
	Greater Boston		L+1.35			1.52			8/23/17		—				—				106,093			—			—			—			106,093
	San Diego, Maryland, and Seattle		7.75			7.75			4/1/20		1,570				1,696				1,832			1,979			2,138			104,352			113,567
	San Diego		4.66			4.66			1/1/23		1,403				1,464				1,540			1,614			1,692			31,674			39,387
	San Francisco Bay Area		6.5			6.5			6/1/37		18				19				20			22			23			728			830
	Unamortized premiums										214				55				—			—			—			—			269
	Secured notes payable average/subtotal		4.63	%		4.59					61,404				261,098				185,485			3,615			3,853			136,754			652,209
	2016 Unsecured Senior Bank Term Loan		L+1.20	%		1.42			7/31/16		—				375,000				—			—			—			—			375,000
	2019 Unsecured Senior Bank Term Loan		L+1.20	%		1.67			1/3/19		—				—				—			—			600,000			—			600,000
	$1.5 billion unsecured senior line of credit		L+1.10	%	(3)	1.27			1/3/19		—				—				—			—			304,000			—			304,000
	Unsecured senior notes payable		2.75	%		2.79			1/15/20		—				—				—			—			—			400,000			400,000
	Unsecured senior notes payable		4.6	%		4.61			4/1/22		—				—				—			—			—			550,000			550,000
	Unsecured senior notes payable		3.9	%		3.94			6/15/23		—				—				—			—			—			500,000			500,000
	Unsecured senior notes payable		4.5	%		4.51			7/30/29		—				—				—			—			—			300,000			300,000
	Unamortized discounts										(326		)		(337		)		(350		)	(362		)	(375		)	(880		)	(2,630		)
	Unsecured debt average/subtotal					2.94					(326		)		374,663				(350		)	(362		)	903,625			1,749,120			3,026,370
	Average/total					3.23	%				$	61,078			$	635,761			$	185,135		$	3,253		$	907,478		$	1,885,874		$	3,678,579
	Balloon payments										$	52,532			$	631,243			$	182,093		$	—		$	904,000		$	1,880,238		$	3,650,106
	Principal amortization										8,546				4,518				3,042			3,253			3,478			5,636			28,473
	Total consolidated debt										$	61,078			$	635,761			$	185,135		$	3,253		$	907,478		$	1,885,874		$	3,678,579
	Fixed-rate/hedged variable-rate debt										$	14,286			$	591,418			$	3,042		$	3,253		$	603,478		$	1,885,874		$	3,101,351
	Unhedged variable-rate debt										46,792				44,343				182,093			—			304,000			—			577,228
	Total consolidated debt										$	61,078			$	635,761			$	185,135		$	3,253		$	907,478		$	1,885,874		$	3,678,579
	-1	Represents the weighted average interest rate as of the end of the period plus the impact of debt premiums/discounts and our interest rate swap agreements. The weighted average interest rate excludes bank fees and amortization of loan fees.
	-2	Includes any extension options that we control.
	-3	In addition to the stated rate, the unsecured senior line of credit is subject to an annual facility fee of 0.20%, based on the aggregate commitments outstanding.
Summary of financial covenants under unsecured senior notes payable	The requirements of the key financial covenants under our 2.75% Unsecured Senior Notes, 3.90% Unsecured Senior Notes, 4.60% Unsecured Senior Notes, and 4.50% Unsecured Senior Notes as of December 31, 2014, were as follows:
	Debt Covenant Ratios (1)		Requirement
	Total Debt to Total Assets		Less than or equal to 60%
	Secured Debt to Total Assets		Less than or equal to 40%
	Consolidated EBITDA to Interest Expense		Greater than or equal to 1.5x
	Unencumbered Total Asset Value to Unsecured Debt		Greater than or equal to 150%
	-1	For definitions of the ratios, refer to the indenture filed as Exhibit 4.3 hereto and the related supplemental indentures filed as Exhibits 4.4, 4.7, 4.9, and 4.11 hereto, which are each listed in Item 15 of this report.
Summary of unsecured bank debt [Table Text Block]	The table below reflects the outstanding balances, maturity dates, applicable rates, and facility fees for each of these facilities.
			Balance as of December 31, 2014				As of December 31, 2014
	Facility						Maturity Date (1)		Applicable Rate		Facility Fee
	2016 Unsecured Senior Bank Term Loan		$	375	million		Jul-16		L+1.20%		N/A
	2019 Unsecured Senior Bank Term Loan		$	600	million		Jan-19		L+1.20%		N/A
	$1.5 billion unsecured senior line of credit		$	304	million		Jan-19		L+1.10%		0.20%
	-1	Includes any extension options that we control.
Summary of financial covenants under unsecured senior line of credit and unsecured senior bank term loans	The requirements of the key financial covenants under our unsecured senior line of credit and unsecured senior bank term loans as of December 31, 2014, were as follows:
	Covenant Ratios (1)		Requirement
	Leverage Ratio		Less than or equal to 60.0%
	Secured Debt Ratio		Less than or equal to 45.0%
	Fixed Charge Coverage Ratio		Greater than or equal to 1.50x
	Unsecured Leverage Ratio		Less than or equal to 60.0%
	Unsecured Interest Coverage Ratio		Greater than or equal to 1.50x
	-1	For definitions of the ratios, refer to the amended unsecured senior line of credit and unsecured senior bank term loan agreements filed as Exhibits 10.24, 10.25, 10.26, and 10.27 hereto, which are listed in Item 15 of this report.
Schedule of interest expense incurred	The following table summarizes interest expense for the years ended December 31, 2014, 2013, and 2012 (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Gross interest	$	126,404			$	128,567			$	131,935
	Capitalized interest	(47,105		)		(60,615		)		(62,751		)
	Interest expense (1)	$	79,299			$	67,952			$	69,184
	(1)    Includes interest expense related to and classified in income from discontinued operations in the accompanying consolidated statements of income.
Summary of secured construction loans	The following table summarizes our secured construction loans as of December 31, 2014 (dollars in thousands):
	Market		Stated Rate				Maturity Date				Outstanding Balance				Remaining Commitments				Total Aggregate Commitments
	San Francisco Bay Area			L+1.50	%		7/1/15		(1)		$	46,792			$	8,208			$	55,000
	San Francisco Bay Area			L+1.40	%		6/1/16		(2)		19,343				16,657				36,000
	Greater Boston			L+1.35	%		8/23/17		(3)		106,093				144,307				250,400
											$	172,228			$	169,172			$	341,400
	-1	We have two, one-year options to extend the stated maturity date to July 1, 2017, subject to certain conditions.
	-2	We have two, one-year options to extend the stated maturity date to June 1, 2018, subject to certain conditions.
	-3	We have a one-year option to extend the stated maturity date to August 23, 2018, subject to certain conditions.

Interest_rate_swap_agreements_1

Interest rate swap agreements (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding interest rate hedge agreements designated as cash flow hedges of interest rate risk	We had the following outstanding interest rate swap agreements that were designated as cash flow hedges of interest rate risk as of December 31, 2014 (dollars in thousands):
	Effective Date		Maturity Date	Number of Contracts	Weighted Average Interest Pay	Fair Value as of 12/31/14			Notional Amount in Effect as of
					Rate (1)				12/31/14		12/31/15		12/31/16
	31-Dec-13		31-Mar-15	2	0.23%	$	(43	)	$	250,000	$	—	$	—
	31-Mar-14		31-Mar-15	4	0.21%	(22		)	200,000		—		—
	31-Dec-14		31-Mar-16	3	0.53%	(625		)	500,000		500,000		—
	31-Mar-16		31-Mar-17	3	1.40%	(219		)	—		—		500,000
	Total					$	(909	)	$	950,000	$	500,000	$	500,000
	-1	In addition to the interest pay rate for each swap agreement, interest is also payable at an applicable margin for borrowings outstanding as of December 31, 2014. Borrowings under our unsecured senior bank term loans include an applicable margin of 1.20% and borrowings outstanding under our unsecured senior line of credit include an applicable margin of 1.10%.

Accounts_payable_accrued_expen1

Accounts payable, accrued expenses, and tenant security deposits (Tables)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Summary of components of accounts payable, accrued expenses, and tenant security deposits	The following table summarizes the components of accounts payable, accrued expenses, and tenant security deposits as of December 31, 2014 and 2013 (in thousands):
		December 31,
		2014		2013
	Accounts payable and accrued expenses	$	127,828	$	98,037
	Accrued construction	91,110		78,098
	Acquired below market leases	8,810		11,405
	Conditional asset retirement obligations	9,108		7,386
	Deferred rent liability	36,231		35,134
	Interest rate swap liabilities	909		6,191
	Prepaid rent and tenant security deposits	193,699		188,241
	Other liabilities	21,390		10,850
	Total	$	489,085	$	435,342

Earnings_per_share_Tables

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Reconciliation of the numerators and denominators of the basic and diluted earnings per share computations	The table below is a reconciliation of the numerators and denominators of the basic and diluted EPS computations for the years ended December 31, 2014, 2013, and 2012 (in thousands, except per share amounts):
		Year Ended December 31,
		2014			2013			2012
	Income from continuing operations	$	99,142		$	134,525		$	94,848
	Gain on sales of real estate – land parcels	6,403			4,824			1,864
	Net income attributable to noncontrolling interests	(5,204		)	(4,032		)	(3,402		)
	Dividends on preferred stock	(25,698		)	(25,885		)	(27,328		)
	Preferred stock redemption charge	(1,989		)	—			(5,978		)
	Net income attributable to unvested restricted stock awards	(1,774		)	(1,581		)	(1,190		)
	Income from continuing operations attributable to Alexandria’s common stockholders – basic and diluted	70,880			107,851			58,814
	Income from discontinued operations	1,233			900			8,816
	Net income attributable to Alexandria’s common stockholders – basic and diluted	$	72,113		$	108,751		$	67,630
	Weighted average shares of common stock outstanding – basic and diluted	71,170			68,038			62,160
	EPS attributable to Alexandria’s common stockholders – basic and diluted:
	Continuing operations	$	0.99		$	1.59		$	0.95
	Discontinued operations	0.02			0.01			0.14
	EPS – basic and diluted	$	1.01		$	1.6		$	1.09

Income_taxes_Tables

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Reconciliation of GAAP net income to taxable income as filed with the IRS	The following reconciles GAAP net income to taxable income as filed with the IRS for the years ended December 31, 2013 and 2012 (in thousands and unaudited):
			Year ended December 31,
			2013				2012
	Net income		$	140,249			$	105,528
	Net income attributable to noncontrolling interests		(4,032		)		(3,402		)
	Book/tax differences:
	Rental revenue recognition		16,800				11,607
	Depreciation and amortization		12,936				15,501
	Share-based compensation		13,754				11,488
	Interest income (expense)		356				(8,068		)
	Sales of property		(14,284		)		394
	Impairments		—				13,450
	Other		10,284				2,268
	Taxable income, before dividend deduction		176,063				148,766
	Dividend deduction necessary to eliminate taxable income (1)		(176,063		)		(148,766		)
	Estimated income subject to federal income tax		$	—			$	—
	-1	Total common stock and preferred stock dividend distributions paid were approximately $195.0 million and $154.3 million for the years ended December 31, 2013 and 2012, respectively.
Schedule of income tax treatment of distribution and dividends declared	The income tax treatment of distributions and dividends declared on our common stock, our Series C Preferred Stock, our Series D Convertible Preferred Stock, and our Series E Preferred Stock for the years ended December 31, 2014, 2013, and 2012, was as follows (unaudited):
		Common Stock											Series C Preferred Stock			Series D Convertible Preferred Stock									Series E Preferred Stock
		Year Ended December 31,
		2014				2013				2012			2012			2014			2013			2012			2014			2013			2012
	Ordinary income	91.8		%		85.9		%		85		%	89.1		%	100		%	97.2		%	89.1		%	100		%	97.2		%	89.1		%
	Return of capital	8.2				11.6				4.6			—			—			—			—			—			—			—
	Capital gains	—				2.5				10.4			10.9			—			2.8			10.9			—			2.8			10.9
	Total	100		%		100		%		100		%	100		%	100		%	100		%	100		%	100		%	100		%	100		%
	Dividends declared	$	2.88			$	2.61			$	2.09		$	0.5234375		$	1.75		$	1.75		$	1.75		$	1.6125		$	1.6125		$	1.34375

Commitments_and_contingencies_1

Commitments and contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum lease obligations under non-cancelable ground and other operating leases	Future minimum lease obligations under non-cancelable ground and other operating leases as of December 31, 2014, were as follows (in thousands):
	Year	Office Leases		Ground Leases		Total
	2015	$	1,501	$	9,828	$	11,329
	2016	1,490		10,436		11,926
	2017	1,561		10,506		12,067
	2018	1,632		10,595		12,227
	2019	2,115		8,978		11,093
	Thereafter	—		616,739		616,739
		$	8,299	$	667,082	$	675,381

Stockholders_equity_Tables

Stockholders' equity (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Accumulated other comprehensive loss attributable to Alexandria Real Estate Equities, Inc.	Accumulated other comprehensive loss attributable to Alexandria Real Estate Equities, Inc. consists of the following (in thousands):
		Unrealized Gain on Marketable Securities			Unrealized Loss on Interest Rate			Unrealized Loss on Foreign Currency Translation			Total
					Swap Agreements
	Balance as of December 31, 2013	$	1,590		$	(3,321	)	$	(34,473	)	$	(36,204	)
	Other comprehensive income (loss) before reclassifications	51,135			(4,459		)	(18,075		)	28,601
	Amounts reclassified from other comprehensive (loss) income	(358		)	6,871			(208		)	6,305
	Amounts attributable to noncontrolling interest	—			—			670			670
	Net other comprehensive income (loss)	50,777			2,412			(17,613		)	35,576
	Balance as of December 31, 2014	$	52,367		$	(909	)	$	(52,086	)	$	(628	)

Sharebased_compensation_Tables

Share-based compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of stock option activity	A summary of the stock option activity under our stock plan and related information for the years ended December 31, 2014, 2013, and 2012, follows:
		Number of		Intrinsic Value of Options Exercised
		Stock Options
	Outstanding as of December 31, 2011	3,600
	Granted	—
	Exercised	(3,600	)	$	94,968
	Forfeited	—
	Outstanding as of December 31, 2012	—
	Granted	—
	Outstanding as of December 31, 2013	—
	Granted	—
	Outstanding as of December 31, 2014	—
Schedule of nonvested share award activity	A summary of the share awards activity under our stock plan and related information for the years ended December 31, 2014, 2013, and 2012, follows:
					Number of Share Awards			Weighted Average
								Grant Date
								Fair Value Per Share
	Outstanding as of December 31, 2011				550,763			$		71.04
	Granted				310,240			$		72.85
	Vested				(297,669		)	$		68.52
	Forfeited				(2,266		)	$		74.3
	Outstanding as of December 31, 2012				561,068			$		73.37
	Granted				338,915			$		63.74
	Vested				(323,594		)	$		71.78
	Forfeited				(6,616		)	$		72.96
	Outstanding as of December 31, 2013				569,773			$		68.54
	Granted				416,954			$		72.25
	Vested				(286,681		)	$		72.91
	Forfeited				(25,077		)	$		55.72
	Outstanding as of December 31, 2014				674,969			$		69.46
		Year Ended December 31,
	(In thousands)	2014			2013			2012
	Total fair value of share awards vested	$	20,903		$	23,228		$	20,396
	Total compensation recognized for awards, net of capitalization	$	13,996		$	15,552		$	14,160
	Capitalized stock compensation	$	7,583		$	8,193		$	7,768

Noncontrolling_interests_Nonco

Noncontrolling interests Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interests [Abstract]
Income from continuing operations and discontinued operations attributable to Alexandria Real Estate Equities, Inc. excluding amounts attributable to noncontrolling interests [Table Text Block]	The following table represents income from continuing operations and discontinued operations attributable to Alexandria for the years ended December 31, 2014, 2013, and 2012, excluding the amounts attributable to these noncontrolling interests:
		Year Ended December 31,
		2014		2013		2012
	Income from continuing operations attributable to Alexandria	$	100,341	$	135,317	$	93,310
	Income from discontinued operations	$	1,233	$	900	$	8,816

Discontinued_operationsassets_1

Discontinued operations/assets held for sale (Tables)	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Summary of net assets of discontinued operations and income from discontinued operations, net	The following is a summary of net assets “held for sale” as of December 31, 2014 and 2013, including the assets classified as “held for sale” subsequent to our adoption of the new ASU (in thousands):
		As of December 31,
		2014				2013
	Properties “held for sale”	$	173,706			$	7,644
	Other assets	10,147				103
	Total assets	183,853				7,747
	Total liabilities	(6,044		)		(266		)
	Net assets “held for sale” (1)	$	177,809			$	7,481
	-1	As of December 31, 2014, net assets “held for sale” was comprised of the five properties which were “held for sale”, including the two properties subsequently sold in January 2015, and one property classified as “held for sale” and included in discontinued operations prior to the adoption of the ASU.
	The following is a summary of income from discontinued operations related to each asset classified as discontinued operations prior to the adoption of the new ASU on October 1, 2014, for the years ended December 31, 2014, 2013, and 2012, (in thousands):
			Year Ended December 31,
			2014				2013			2012
	Total revenues		$	—			$	4,657		$	36,283
	Operating expenses		(605		)		(1,981		)	(11,313		)
	Total revenues less operating expenses from discontinued operations		(605		)		2,676			24,970
	Depreciation expense		—				(1,655		)	(6,318		)
	Gain (loss) on sales of real estate		1,838				(121		)	1,564
	Impairment of real estate		—				—			(11,400		)
	Income from discontinued operations (1)		$	1,233			$	900		$	8,816
	-1	Income from discontinued operations includes the results of operations of three properties that were disposed of during the year ended December 31, 2014, and the results of one property which was classified as “held for sale” prior to adoption of the new ASU and included as discontinued operations as of December 31, 2014, as well as the results of operations (prior to disposition) and gain (loss) on sale of real estate attributable to 16 properties sold during the period from January 1, 2012, to December 31, 2014.
	The following is a summary of the loss included in our income from continuing operations for the year ended December 31, 2014, from assets classified as “held for sale” subsequent to our adoption of the new ASU (in thousands):
			Year Ended December 31,
			2014				2013			2012
	Total revenues		$	9,661			$	9,975		$	9,604
	Operating expenses		(3,760		)		(3,525		)	(3,156		)
	Total revenues less operating expenses from assets classified as “held for sale”, not qualifying as discontinued operations		5,901				6,450			6,448
	Depreciation expense		(7,005		)		(7,189		)	(7,103		)
	Impairment of real estate		(26,975		)		—			—
	Loss from assets classified as "held for sale", not qualifying as discontinued operations (1)		$	(28,079	)		$	(739	)	$	(655	)
	-1	Includes the results of operations of four properties with an aggregate 1,036,585 RSF that were classified as “held for sale” as of December 31, 2014, but do not qualify for classification as discontinued operations. In January 2015, we subsequently sold two of these properties with an aggregate 802,399 RSF. For additional information, refer to the section titled “Basis of Presentation and Summary of Significant Accounting Policies” in Note 2 to our audited consolidated financial statements under Item 15 of this Report. As of December 31, 2013, and 2012, we did not have any assets classified as “held for sale”, not qualifying as discontinued operations.

Quarterly_financial_data_unaud1

Quarterly financial data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of summary of consolidated financial information on a quarterly basis	The following is a summary of consolidated financial information on a quarterly basis for 2014 and 2013 (in thousands, except per share amounts):
			Quarter
	2014		First		Second		Third		Fourth
	Revenues		$	176,186	$	176,402	$	185,615	$	188,674
	Net income (loss) attributable to Alexandria Real Estate Equities, Inc.’s common stockholders		$	32,709	$	27,932	$	27,626	$	(16,154	)
	Earnings per share attributable to Alexandria Real Estate Equities, Inc.’s common stockholders:
	Basic and diluted (1)		$	0.46	$	0.39	$	0.39	$	(0.23	)	(2)
			Quarter
	2013		First		Second		Third		Fourth
	Revenues		$	150,083	$	153,930	$	158,315	$	168,823
	Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders		$	22,442	$	25,483	$	24,579	$	36,247
	Earnings per share attributable to Alexandria Real Estate Equities, Inc.’s common stockholders:
	Basic and diluted (1)		$	0.36	$	0.38	$	0.35	$	0.51
	-1	Quarterly earnings per common share amounts may not total to the annual amounts due to rounding and due to the increase in the weighted average shares of common stock outstanding.
	-2	Results for the fourth quarter of 2014 include an aggregate net loss of $46.2 million, or $0.65 per share, related to impairments of real estate and a preferred stock redemption charge, partially offset by gains on sales of real estate. See further discussion of impairments of real estate and gains on real estate in Note 3 – “Investments in Real Estate.”

Condensed_consolidating_financ1

Condensed consolidating financial information (Tables)	12 Months Ended
	Dec. 31, 2014
Condensed consolidating financial information
Condensed Consolidating Balance Sheet	Consolidating Balance Sheet
	as of December 31, 2014
	(In thousands)
		Alexandria Real Estate Equities, Inc.			Alexandria			Combined			Eliminations			Consolidated
		(Issuer)			Real Estate			Non-
					Equities, L.P.			Guarantor
					(Guarantor			Subsidiaries
					Subsidiary)
	Assets
	Investments in real estate	$	—		$	—		$	7,226,016		$	—		$	7,226,016
	Cash and cash equivalents	52,491			63			33,457			—			86,011
	Restricted cash	67			—			26,817			—			26,884
	Tenant receivables	—			—			10,548			—			10,548
	Deferred rent	—			—			234,124			—			234,124
	Deferred leasing and financing costs	35,462			—			166,336			—			201,798
	Investments	—			5,235			231,154			—			236,389
	Investments in and advances to affiliates	6,874,866			6,295,852			128,943			(13,299,661		)	—
	Other assets	19,461			—			94,805			—			114,266
	Total assets	$	6,982,347		$	6,301,150		$	8,152,200		$	(13,299,661	)	$	8,136,036
	Liabilities, Noncontrolling Interests, and Equity
	Secured notes payable	$	—		$	—		$	652,209		$	—		$	652,209
	Unsecured senior notes payable	1,747,370			—			—			—			1,747,370
	Unsecured senior line of credit	304,000			—			—			—			304,000
	Unsecured senior bank term loans	975,000			—			—			—			975,000
	Accounts payable, accrued expenses, and tenant security deposits	69,013			—			420,072			—			489,085
	Dividends payable	58,525			—			289			—			58,814
	Total liabilities	3,153,908			—			1,072,570			—			4,226,478
	Redeemable noncontrolling interests	—			—			14,315			—			14,315
	Alexandria’s stockholders’ equity	3,828,439			6,301,150			6,998,511			(13,299,661		)	3,828,439
	Noncontrolling interests	—			—			66,804			—			66,804
	Total equity	3,828,439			6,301,150			7,065,315			(13,299,661		)	3,895,243
	Total liabilities, noncontrolling interests, and equity	$	6,982,347		$	6,301,150		$	8,152,200		$	(13,299,661	)	$	8,136,036
	Condensed Consolidating Balance Sheet
	as of December 31, 2013
	(In thousands)
		Alexandria			Alexandria			Combined			Eliminations			Consolidated
		Real Estate			Real Estate			Non-
		Equities, Inc.			Equities, L.P.			Guarantor
		(Issuer)			(Guarantor			Subsidiaries
					Subsidiary)
	Assets
	Investments in real estate	$	—		$	—		$	6,776,914		$	—		$	6,776,914
	Cash and cash equivalents	14,790			—			42,906			—			57,696
	Restricted cash	55			—			27,654			—			27,709
	Tenant receivables	—			—			9,918			—			9,918
	Deferred rent	—			—			190,425			—			190,425
	Deferred leasing and financing costs	36,901			—			155,757			—			192,658
	Investments	—			10,868			129,420			—			140,288
	Investments in and advances to affiliates	6,299,551			5,823,058			119,421			(12,242,030		)	—
	Other assets	20,226			—			113,930			—			134,156
	Total assets	$	6,371,523		$	5,833,926		$	7,566,345		$	(12,242,030	)	$	7,529,764
	Liabilities, Noncontrolling Interests, and Equity
	Secured notes payable	$	—		$	—		$	708,831		$	—		$	708,831
	Unsecured senior notes payable	1,048,230			—			—			—			1,048,230
	Unsecured senior line of credit	204,000			—			—			—			204,000
	Unsecured senior bank term loans	1,100,000			—			—			—			1,100,000
	Accounts payable, accrued expenses, and tenant security deposits	48,373			—			386,969			—			435,342
	Dividends payable	54,131			—			289			—			54,420
	Total liabilities	2,454,734			—			1,096,089			—			3,550,823
	Redeemable noncontrolling interests	—			—			14,444			—			14,444
	Alexandria’s stockholders’ equity	3,916,789			5,833,926			6,408,104			(12,242,030		)	3,916,789
	Noncontrolling interests	—			—			47,708			—			47,708
	Total equity	3,916,789			5,833,926			6,455,812			(12,242,030		)	3,964,497
	Total liabilities, noncontrolling interests, and equity	$	6,371,523		$	5,833,926		$	7,566,345		$	(12,242,030	)	$	7,529,764
Condensed Consolidating Statements of Income	Condensed Consolidating Statement of Income
	for the Year Ended December 31, 2014
	(In thousands)
		Alexandria			Alexandria			Combined			Eliminations			Consolidated
		Real Estate			Real Estate			Non-
		Equities, Inc.			Equities, L.P.			Guarantor
		(Issuer)			(Guarantor			Subsidiaries
					Subsidiary)
	Revenues:
	Rental	$	—		$	—		$	544,153		$	—		$	544,153
	Tenant recoveries	—			—			173,480			—			173,480
	Other income (expense)	12,006			(3,277		)	14,845			(14,330		)	9,244
	Total revenues	12,006			(3,277		)	732,478			(14,330		)	726,877
	Expenses:
	Rental operations	—			—			219,164			—			219,164
	General and administrative	45,793			—			22,067			(14,330		)	53,530
	Interest	58,159			—			21,140			—			79,299
	Depreciation and amortization	5,748			—			218,348			—			224,096
	Impairment of real estate	—			—			51,675			—			51,675
	Loss on early extinguishment of debt	525			—			—			—			525
	Total expenses	110,225			—			532,394			(14,330		)	628,289
	Equity in earnings of unconsolidated JVs	—			—			554			—			554
	Equity in earnings of affiliates	199,800			188,269			3,665			(391,734		)	—
	Income from continuing operations	101,581			184,992			204,303			(391,734		)	99,142
	(Loss) income from discontinued operations	(7		)	—			1,240			—			1,233
	Gain on sales of real estate – land parcels	—			—			6,403			—			6,403
	Net income	101,574			184,992			211,946			(391,734		)	106,778
	Dividends on preferred stock	(25,698		)	—			—			—			(25,698		)
	Preferred stock redemption charge	(1,989		)	—			—			—			(1,989		)
	Net income attributable to noncontrolling interests	—			—			(5,204		)	—			(5,204		)
	Net income attributable to unvested restricted stock awards	(1,774		)	—			—			—			(1,774		)
	Net income attributable to Alexandria’s common stockholders	$	72,113		$	184,992		$	206,742		$	(391,734	)	$	72,113
	Condensed Consolidating Statement of Income
	for the Year Ended December 31, 2013
	(In thousands)
		Alexandria			Alexandria			Combined			Eliminations			Consolidated
		Real Estate			Real Estate			Non-
		Equities, Inc.			Equities, L.P.			Guarantor
		(Issuer)			(Guarantor			Subsidiaries
					Subsidiary)
	Revenues:
	Rental	$	—		$	—		$	467,764		$	—		$	467,764
	Tenant recoveries	—			—			150,095			—			150,095
	Other income (expense)	10,423			(74		)	15,912			(12,969		)	13,292
	Total revenues	10,423			(74		)	633,771			(12,969		)	631,151
	Expenses:
	Rental operations	—			—			189,039			—			189,039
	General and administrative	43,528			—			17,961			(12,969		)	48,520
	Interest	43,284			—			24,668			—			67,952
	Depreciation and amortization	5,907			—			183,216			—			189,123
	Loss on early extinguishment of debt	1,992			—			—			—			1,992
	Total expenses	94,711			—			414,884			(12,969		)	496,626
	Equity in earnings of affiliates	220,158			205,993			4,067			(430,218		)	—
	Income from continuing operations	135,870			205,919			222,954			(430,218		)	134,525
	Income from discontinued operations	347			—			553			—			900
	Gain on sales of real estate – land parcels	—			—			4,824			—			4,824
	Net income	136,217			205,919			228,331			(430,218		)	140,249
	Dividends on preferred stock	(25,885		)	—			—			—			(25,885		)
	Net income attributable to noncontrolling interests	—			—			(4,032		)	—			(4,032		)
	Net income attributable to unvested restricted stock awards	(1,581		)	—			—			—			(1,581		)
	Net income attributable to Alexandria’s common stockholders	$	108,751		$	205,919		$	224,299		$	(430,218	)	$	108,751
	Condensed Consolidating Statement of Income
	for the Year Ended December 31, 2012
	(In thousands)
	Alexandria			Alexandria			Combined			Eliminations			Consolidated
	Real Estate			Real Estate			Non-
	Equities, Inc.			Equities, L.P.			Guarantor
	(Issuer)			(Guarantor			Subsidiaries
				Subsidiary)
Revenues:
Rental	$	—		$	—		$	422,793		$	—		$	422,793
Tenant recoveries	—			—			133,280			—			133,280
Other income	6,891			1,292			23,294			(13,053		)	18,424
Total revenues	6,891			1,292			579,367			(13,053		)	574,497
Expenses:
Rental operations	—			—			172,756			—			172,756
General and administrative	44,306			3			16,491			(13,053		)	47,747
Interest	46,677			—			22,507			—			69,184
Depreciation and amortization	5,384			—			180,303			—			185,687
Impairment of real estate	—			—			2,050			—			2,050
Loss on early extinguishment of debt	2,225			—			—			—			2,225
Total expenses	98,592			3			394,107			(13,053		)	479,649
Equity in earnings of affiliates	194,566			183,139			3,638			(381,343		)	—
Income from continuing operations	102,865			184,428			188,898			(381,343		)	94,848
(Loss) income from discontinued operations	(739		)	—			9,555			—			8,816
Gain on sales of real estate – land parcels	—			—			1,864			—			1,864
Net income	102,126			184,428			200,317			(381,343		)	105,528
Dividends on preferred stock	(27,328		)	—			—			—			(27,328		)
Preferred stock redemption charge	(5,978		)	—			—			—			(5,978		)
Net income attributable to noncontrolling interests	—			—			(3,402		)	—			(3,402		)
Net income attributable to unvested restricted stock awards	(1,190		)	—			—			—			(1,190		)
Net income attributable to Alexandria’s common stockholders	$	67,630		$	184,428		$	196,915		$	(381,343	)	$	67,630
Condensed Consolidating Statement Comprehensive Income	Condensed Consolidating Statement of Comprehensive Income
	for the Year Ended December 31, 2014
	(In thousands)
		Alexandria			Alexandria			Combined			Eliminations			Consolidated
		Real Estate			Real Estate			Non-
		Equities, Inc.			Equities, L.P.			Guarantor
		(Issuer)			(Guarantor			Subsidiaries
					Subsidiary)
	Net income	$	101,574		$	184,992		$	211,946		$	(391,734	)	$	106,778
	Other comprehensive income:
	Unrealized gains on marketable securities:
	Unrealized holding gains arising during the year	—			148			50,987			—			51,135
	Reclassification adjustment for losses (gains) included in net income	—			292			(650		)	—			(358		)
	Unrealized gains on marketable securities	—			440			50,337			—			50,777
	Unrealized gains on interest rate swap agreements:
	Unrealized interest rate swap losses arising during the year	(4,459		)	—			—			—			(4,459		)
	Reclassification adjustment for amortization of interest expense included in net income	6,871			—			—			—			6,871
	Unrealized gains on interest rate swap agreements	2,412			—			—			—			2,412
	Unrealized losses on foreign currency translation:
	Unrealized foreign currency translation losses arising during the year	(318		)	—			(17,757		)	—			(18,075		)
	Reclassification adjustment for gains included in net income	—			—			(208		)	—			(208		)
	Unrealized losses on foreign currency translation	(318		)	—			(17,965		)	—			(18,283		)
	Total other comprehensive income	2,094			440			32,372			—			34,906
	Comprehensive income	103,668			185,432			244,318			(391,734		)	141,684
	Less: comprehensive income attributable to noncontrolling interests	—			—			(4,534		)	—			(4,534		)
	Comprehensive income attributable to Alexandria’s common stockholders	$	103,668		$	185,432		$	239,784		$	(391,734	)	$	137,150
	Condensed Consolidating Statement of Comprehensive Income
	for the Year Ended December 31, 2013
	(In thousands)
		Alexandria			Alexandria			Combined			Eliminations			Consolidated
		Real Estate			Real Estate			Non-
		Equities, Inc.			Equities, L.P.			Guarantor
		(Issuer)			(Guarantor			Subsidiaries
					Subsidiary)
	Net income	$	136,217		$	205,919		$	228,331		$	(430,218	)	$	140,249
	Other comprehensive income (loss):
	Unrealized (losses) gains on marketable securities:
	Unrealized holding (losses) gains arising during the year	—			(438		)	1,738			—			1,300
	Reclassification adjustment for losses (gains) included in net income	—			148			(1,331		)	—			(1,183		)
	Unrealized (losses) gains on marketable securities	—			(290		)	407			—			117
	Unrealized gains on interest rate swap agreements:
	Unrealized interest rate swap gains arising during the year	1,918			—			—			—			1,918
	Reclassification adjustment for amortization of interest expense included in net income	15,422			—			—			—			15,422
	Unrealized gains on interest rate swap agreements	17,340			—			—			—			17,340
	Unrealized foreign currency translation losses	—			—			(28,912		)	—			(28,912		)
	Total other comprehensive income (loss)	17,340			(290		)	(28,505		)	—			(11,455		)
	Comprehensive income	153,557			205,629			199,826			(430,218		)	128,794
	Less: comprehensive income attributable to noncontrolling interests	—			—			(3,948		)	—			(3,948		)
	Comprehensive income attributable to Alexandria’s common stockholders	$	153,557		$	205,629		$	195,878		$	(430,218	)	$	124,846
	Condensed Consolidating Statement of Comprehensive Income
	for the Year Ended December 31, 2012
	(In thousands)
		Alexandria			Alexandria			Combined			Eliminations			Consolidated
		Real Estate			Real Estate			Non-
		Equities, Inc.			Equities, L.P.			Guarantor
		(Issuer)			(Guarantor			Subsidiaries
					Subsidiary)
	Net income	$	102,126		$	184,428		$	200,317		$	(381,343	)	$	105,528
	Other comprehensive income:
	Unrealized (losses) gains on marketable securities:
	Unrealized holding (losses) gains arising during the year	—			(319		)	1,309			—			990
	Reclassification adjustment for losses (gains) included in net income	—			155			(3,506		)	—			(3,351		)
	Unrealized losses on marketable securities	—			(164		)	(2,197		)	—			(2,361		)
	Unrealized gains on interest rate swaps:
Unrealized interest rate swap losses arising during the year	(9,990		)	—			—			—			(9,990		)
Reclassification adjustment for amortization of interest expense included in net income	22,309			—			—			—			22,309
Unrealized gains on interest rate swaps	12,319			—			—			—			12,319
Unrealized foreign currency translation losses	—			—			(318		)	—			(318		)
Total other comprehensive income (loss)	12,319			(164		)	(2,515		)	—			9,640
Comprehensive income	114,445			184,264			197,802			(381,343		)	115,168
Less: comprehensive income attributable to noncontrolling interests	—			—			(3,364		)	—			(3,364		)
Comprehensive income attributable to Alexandria’s common stockholders	$	114,445		$	184,264		$	194,438		$	(381,343	)	$	111,804
Condensed Consolidating Statement Cash Flows	Condensed Consolidating Statement of Cash Flows
	for the Year Ended December 31, 2014
	(In thousands)
		Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
		Estate Equities,			Estate Equities,			Non-Guarantor
		Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
					Subsidiary)
	Operating Activities
	Net income	$	101,574		$	184,992		$	211,946		$	(391,734	)	$	106,778
	Adjustments to reconcile net income to net cash (used in) provided by operating activities:
	Depreciation and amortization	5,748			—			218,348			—			224,096
	Loss on early extinguishment of debt	525			—			—			—			525
	Gain on sales of real estate – rental properties	—			—			(1,838		)	—			(1,838		)
	Gain on sales of real estate – land parcels	—			—			(6,403		)	—			(6,403		)
	Impairment of real estate	—			—			51,675			—			51,675
	Equity in earnings from unconsolidated joint ventures	—			—			(554		)	—			(554		)
	Distributions of earnings from unconsolidated joint ventures	—			—			549			—			549
	Amortization of loan fees and costs	7,355			—			3,554			—			10,909
	Amortization of debt premiums/discounts	232			—			(115		)	—			117
	Amortization of acquired below market leases	—			—			(2,845		)	—			(2,845		)
	Deferred rent	—			—			(44,726		)	—			(44,726		)
	Stock compensation expense	13,996			—			—			—			13,996
	Equity in earnings of affiliates	(199,800		)	(188,269		)	(3,665		)	391,734			—
	Investment gains	—			—			(11,613		)	—			(11,613		)
	Investment losses	—			3,047			6,240			—			9,287
	Changes in operating assets and liabilities:
	Restricted cash	(12		)	—			4,153			—			4,141
	Tenant receivables	—			—			(673		)	—			(673		)
	Deferred leasing costs	17			—			(38,299		)	—			(38,282		)
	Other assets	(7,785		)	—			319			—			(7,466		)
	Accounts payable, accrued expenses, and tenant security deposits	25,877			—			775			—			26,652
	Net cash (used in) provided by operating activities	(52,273		)	(230		)	386,828			—			334,325
	Investing Activities
	Proceeds from sales of real estate	—			—			81,580			—			81,580
	Additions to real estate	(65		)	—			(497,708		)	—			(497,773		)
	Purchase of real estate	—			—			(127,887		)	—			(127,887		)
	Deposits for investing activities	—			—			(10,282		)	—			(10,282		)
	Change in restricted cash related to construction projects	—			—			1,665			—			1,665
	Investment in unconsolidated joint venture	—			—			(70,758		)	—			(70,758		)
	Investments in subsidiaries	(334,764		)	(251,358		)	(13,441		)	599,563			—
	Additions to investments	—			(150		)	(60,080		)	—			(60,230		)
	Proceeds from sales of investments	—			1,052			17,921			—			18,973
	Proceeds from repayment of notes receivable	—			—			29,883			—			29,883
	Net cash used in investing activities	$	(334,829	)	$	(250,456	)	$	(649,107	)	$	599,563		$	(634,829	)
	Condensed Consolidating Statement of Cash Flows (continued)
	for the Year Ended December 31, 2014
	(In thousands)
		Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
		Estate Equities,			Estate Equities,			Non-Guarantor
		Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
					Subsidiary)
	Financing Activities
	Borrowings from secured notes payable	$	—		$	—		$	126,215		$	—		$	126,215
	Repayments of borrowings from secured notes payable	—			—			(231,051		)	—			(231,051		)
	Proceeds from issuance of unsecured senior notes payable	698,908			—			—			—			698,908
	Principal borrowings from unsecured senior line of credit	1,168,000			—			—			—			1,168,000
	Repayments of borrowings from unsecured senior line of credit	(1,068,000		)	—			—			—			(1,068,000		)
	Repayment of unsecured senior bank term loan	(125,000		)	—			—			—			(125,000		)
	Redemption of Series D Cumulative Convertible Preferred Stock	(14,414		)	—			—			—			(14,414		)
	Transfer to/from parent company	103			250,749			348,711			(599,563		)	—
	Change in restricted cash related to financing activities	—			—			(1,409		)	—			(1,409		)
	Loan fees and costs paid	(6,523		)	—			(1,576		)	—			(8,099		)
	Dividends paid on common stock	(202,386		)	—			—			—			(202,386		)
	Dividends paid on preferred stock	(25,885		)	—			—			—			(25,885		)
Distributions to redeemable noncontrolling interests	—			—			(1,191		)	—			(1,191		)
Contributions by noncontrolling interests	—			—			19,410			—			19,410
Distributions to noncontrolling interests	—			—			(3,786		)	—			(3,786		)
Net cash provided by financing activities	424,803			250,749			255,323			(599,563		)	331,312
Effect of foreign exchange rate changes on cash and cash equivalents	—			—			(2,493		)	—			(2,493		)
Net increase (decrease) in cash and cash equivalents	37,701			63			(9,449		)	—			28,315
Cash and cash equivalents at beginning of period	14,790			—			42,906			—			57,696
Cash and cash equivalents at end of period	$	52,491		$	63		$	33,457		$	—		$	86,011
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	$	39,871		$	—		$	18,095		$	—		$	57,966
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	$	—		$	—		$	2,000		$	—		2,000
Change in accrued construction	$	—		$	—		$	29,846		$	—		$	29,846
Assumption of secured notes payable in connection with purchase of properties	$	—		$	—		$	(48,329	)	$	—		$	(48,329	)
Condensed Consolidating Statement of Cash Flows
for the Year Ended December 31, 2013
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Operating Activities
Net income	$	136,217		$	205,919		$	228,331		$	(430,218	)	$	140,249
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	5,907			—			184,871			—			190,778
Loss on early extinguishment of debt	1,992			—			—			—			1,992
Gain on sales of real estate – land parcels	—			—			(4,824		)	—			(4,824		)
Loss on sales of real estate – rental properties	—			—			121			—			121
Amortization of loan fees and costs	6,914			—			3,022			—			9,936
Amortization of debt premiums/discounts	111			—			418			—			529
Amortization of acquired below market leases	—			—			(3,316		)	—			(3,316		)
Deferred rent	(82		)	—			(27,853		)	—			(27,935		)
Stock compensation expense	15,552			—			—			—			15,552
Equity in earnings of affiliates	(220,158		)	(205,993		)	(4,067		)	430,218			—
Investment gains	—			(3		)	(7,047		)	—			(7,050		)
Investment losses	—			78			1,402			—			1,480
Changes in operating assets and liabilities:
Restricted cash	(2		)	—			901			—			899
Tenant receivables	—			—			(1,519		)	—			(1,519		)
Deferred leasing costs	(37		)	—			(54,788		)	—			(54,825		)
Other assets	(5,606		)	—			(692		)	—			(6,298		)
Intercompany receivables and payables	3,021			—			(3,021		)	—			—
Accounts payable, accrued expenses, and tenant security deposits	(13,485		)	—			70,443			—			56,958
Net cash (used in) provided by operating activities	(69,656		)	1			382,382			—			312,727
Investing Activities
Proceeds from sale of real estate	10,796			—			143,172			—			153,968
Additions to real estate	—			—			(593,389		)	—			(593,389		)
Purchase of real estate	—			—			(122,069		)	—			(122,069		)
Change in restricted cash related to construction projects	—			—			7,655			—			7,655
Investment in unconsolidated joint venture	—			—			(17,987		)	—			(17,987		)
Investments in subsidiaries	(236,218		)	(276,022		)	(13,445		)	525,685			—
Additions to investments	—			—			(36,078		)	—			(36,078		)
Proceeds from sales of investments	—			1,018			15,507			—			16,525
Net cash used in investing activities	$	(225,422	)	$	(275,004	)	$	(616,634	)	$	525,685		$	(591,375	)
Condensed Consolidating Statement of Cash Flows (continued)
for the Year Ended December 31, 2013
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Financing Activities
Borrowings from secured notes payable	$	—		$	—		$	28,489		$	—		$	28,489
Repayments of borrowings from secured notes payable	—			—			(36,219		)	—			(36,219		)
Proceeds from issuance of senior notes payable	498,561			—			—			—			498,561
Principal borrowings from unsecured senior line of credit	729,000			—			—			—			729,000
Repayments of borrowings from unsecured senior line of credit	(1,091,000		)	—			—			—			(1,091,000		)
Repayments of unsecured senior bank term loans	(250,000		)	—			—			—			(250,000		)
Repurchase of unsecured senior convertible notes	(384		)	—			—			—			(384		)
Transfer to/from parent company	—			273,089			252,596			(525,685		)	—
Change in restricted cash related to financing activities	(1		)	—			2,547			—			2,546
Loan fees and costs paid	(14,383		)	—			(5,545		)	—			(19,928		)
Proceeds from common stock offerings	534,469			—			—			—			534,469
Dividends paid on common stock	(169,076		)	—			—			—			(169,076		)
Dividends paid on preferred stock	(25,885		)	—			—			—			(25,885		)
Distributions to redeemable noncontrolling interests	—			—			(1,191		)	—			(1,191		)
Distributions to noncontrolling interests	—			—			(1,812		)	—			(1,812		)
Net cash provided by financing activities	211,301			273,089			238,865			(525,685		)	197,570
Effect of foreign exchange rate changes on cash and cash equivalents	—			—			(2,197		)	—			(2,197		)
Net (decrease) increase in cash and cash equivalents	(83,777		)	(1,914		)	2,416			—			(83,275		)
Cash and cash equivalents at beginning of period	98,567			1,914			40,490			—			140,971
Cash and cash equivalents at end of period	$	14,790		$	—		$	42,906		$	—		$	57,696
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	$	37,073		$	—		$	22,784		$	—		$	59,857
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	$	29,820		$	—		$	9,000		$	—		$	38,820
Change in accrued construction	$	—		$	—		$	(21,310	)	$	—		$	(21,310	)
Condensed Consolidating Statement of Cash Flows
for the Year Ended December 31, 2012
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Operating Activities
Net income	$	102,126		$	184,428		$	200,317		$	(381,343	)	$	105,528
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,490			—			185,515			—			192,005
Loss on early extinguishment of debt	2,225			—			—			—			2,225
Gain on sales of real estate – rental properties	—			—			(1,564		)	—			(1,564		)
Gain on sales of real estate – land parcels	—			—			(1,864		)	—			(1,864		)
Impairment of real estate	6,400			—			7,050			—			13,450
Amortization of loan fees and costs	9,204			—			628			—			9,832
Amortization of debt premiums/discounts	114			—			397			—			511
Amortization of acquired above and below market leases	—			—			(3,200		)	—			(3,200		)
Deferred rent	(224		)	—			(28,232		)	—			(28,456		)
Equity in earnings of affiliates	(194,566		)	(183,139		)	(3,638		)	381,343			—
Stock compensation expense	14,160			—			—			—			14,160
Investment gains	—			(1,510		)	(13,508		)	—			(15,018		)
Investment losses	—			221			2,416			—			2,637
Changes in operating assets and liabilities:
Restricted cash	(12		)	—			(249		)	—			(261		)
Tenant receivables	11			—			(992		)	—			(981		)
Deferred leasing costs	(305		)	—			(44,794		)	—			(45,099		)
Other assets	1,329			—			(5,398		)	—			(4,069		)
Intercompany receivables and payables	(826		)	—			826			—			—
Accounts payable, accrued expenses, and tenant security deposits	6,172			—			59,525			—			65,697
Net cash (used in) provided by operating activities	(47,702		)	—			353,235			—			305,533
Investing Activities
Proceeds from sales of real estate	—			—			36,179			—			36,179
Additions to real estate	(1,313		)	—			(547,717		)	—			(549,030		)
Purchase of real estate	—			—			(42,171		)	—			(42,171		)
Change in restricted cash related to construction projects	—			—			(9,377		)	—			(9,377		)
Investment in unconsolidated joint venture	—			—			(6,700		)	—			(6,700		)
Distributions from unconsolidated joint venture	—			—			22,250			—			22,250
Investments in subsidiaries	(197,665		)	(158,022		)	(1,179		)	356,866			—
Additions to investments	—			(353		)	(35,941		)	—			(36,294		)
Proceeds from sales of investments	—			2,600			24,443			—			27,043
Net cash used in investing activities	$	(198,978	)	$	(155,775	)	$	(560,213	)	$	356,866		$	(558,100	)
Condensed Consolidating Statement of Cash Flows (continued)
for the Year Ended December 31, 2012
(In thousands)
	Alexandria Real			Alexandria Real			Combined			Eliminations			Consolidated
	Estate Equities,			Estate Equities,			Non-Guarantor
	Inc. (Issuer)			L.P. (Guarantor			Subsidiaries
				Subsidiary)
Financing Activities
Borrowings from secured notes payable	$	—		$	—		$	17,810		$	—		$	17,810
Repayments of borrowings from secured notes payable	—			—			(26,367		)	—			(26,367		)
Proceeds from issuance of unsecured senior notes payable	544,650			—			—			—			544,650
Principal borrowings from unsecured senior line of credit	847,147			—			—			—			847,147
Repayments of borrowings from unsecured senior line of credit	(651,147		)	—			—			—			(651,147		)
Repayments of unsecured senior bank term loan	(250,000		)	—			—			—			(250,000		)
Repurchase of unsecured senior convertible notes	(84,801		)	—			—			—			(84,801		)
Redemption of Series C Cumulative Redeemable Preferred Stock	(129,638		)	—			—			—			(129,638		)
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock	124,868			—			—			—			124,868
Transfer to/from parent company	—			157,689			199,177			(356,866		)	—
Change in restricted cash related to financing activities	—			—			(7,428		)	—			(7,428		)
Loan fees and costs paid	(10,180		)	—			(3,045		)	—			(13,225		)
Proceeds from common stock offerings	97,890			—			—			—			97,890
Proceeds from exercise of stock options	155			—			—			—			155
Dividends paid on common stock	(126,498		)	—			—			—			(126,498		)
Dividends paid on preferred stock	(27,819		)	—			—			—			(27,819		)
Distributions to redeemable noncontrolling interests	—			—			(1,249		)	—			(1,249		)
Redemption of redeemable noncontrolling interests	12			—			(462		)	—			(450		)
Contributions by noncontrolling interests	—			—			1,875			—			1,875
Distributions to noncontrolling interests	—			—			(913		)	—			(913		)
Net cash provided by financing activities	334,639			157,689			179,398			(356,866		)	314,860
Effect of foreign exchange rate changes on cash and cash equivalents	—			—			139			—			139
Net increase (decrease) in cash and cash equivalents	87,959			1,914			(27,441		)	—			$	62,432
Cash and cash equivalents at beginning of period	10,608			—			67,931			—			$	78,539
Cash and cash equivalents at end of period	$	98,567		$	1,914		$	40,490		$	—		$	140,971
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	$	39,298		$	—		$	13,263		$	—		$	52,561
Non-Cash Investing Activities
Note receivable from sale of real estate	$	—		$	—		$	6,125		$	—		$	6,125
Write-off of fully amortized improvements	$	—		$	—		$	(17,730	)	$	—		$	(17,730	)
Change in accrued construction	$	(2,000	)	$	—		$	48,087		$	—		$	46,087

Background_Schedule_of_rentabl

Background Schedule of rentable square feet (Details)	Dec. 31, 2014
	sqft
Real Estate Properties [Line Items]
Area of Real Estate Property	18,729,282
Square Footage of Real Estate Property, Future Development	12,809,188
Total Rentable Square Footage of Asset Base	31,538,470
Operating properties [Member]
Real Estate Properties [Line Items]
Area of Real Estate Property	16,727,985
Development
Real Estate Properties [Line Items]
Area of Real Estate Property	1,857,520
Redevelopment
Real Estate Properties [Line Items]
Area of Real Estate Property	143,777
Near-term value-creation projects in North America (CIP)
Real Estate Properties [Line Items]
Square Footage of Real Estate Property, Future Development	2,715,792
Future value-creation projects
Real Estate Properties [Line Items]
Square Footage of Real Estate Property, Future Development	10,093,396

Background_Details

Background (Details) (USD $)	12 Months Ended
In Billions, unless otherwise specified	Dec. 31, 2014
	Lease
	Tenant
	property
	sqft
Nature of Business [Line Items]
Total Market Capitalization	$10.40
Total Square Footage of Asset Base	31,500,000
Area of Real Estate Property	18,729,282
Square Footage of Real Estate Property, Future Development	12,809,188
Number of leases held	562
Number of client tenants	441
Rentable Square Feet Properties Number	193
Investment-grade client tenants as a percentage of total annualized base rent	56.00%
Percentage of leases which are triple net leases	95.00%
Percentage of leases containing effective annual rent escalations	94.00%
Percentage of leases providing for recapture of certain capital expenditures	93.00%
Minimum
Nature of Business [Line Items]
Lease term of multi-tenant buildings	5 years
Lease term of single-tenant buildings	10 years
Effective annual rent escalations (as a percent)	3.00%
Maximum
Nature of Business [Line Items]
Lease term of multi-tenant buildings	10 years
Lease term of single-tenant buildings	20 years
Effective annual rent escalations (as a percent)	3.50%
Single Tenant | Lessee Concentration
Nature of Business [Line Items]
Number of Properties Leased	87
Single Tenant Properties as Percentage of Total Properties	45.00%

Basis_of_presentation_and_summ2

Basis of presentation and summary of significant accounting policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Basis of presentation
Number of unconsolidated joint ventures	2
Maximum expected period of sale of property (in years)	1 year
FDIC insurance coverage	$250,000
Cost method investment ownership percentage	10.00%	10.00%
Maximum Expected Period for Collection of Receivables	1 year
Allowance for Doubtful Accounts Receivable	0	0
Interest income included in other income	$4,200,000	$4,600,000	$3,400,000
Maximum
Basis of presentation
Percentage of ownership interest criteria	100.00%
Land improvements
Basis of presentation
Estimated useful life	20 years
Buildings and building improvements | Maximum
Basis of presentation
Estimated useful life	40 years
CANADA
Basis of presentation
Number of operating properties	5
CHINA
Basis of presentation
Number of operating properties	2
INDIA
Basis of presentation
Number of operating properties	7

Investments_in_real_estate_Sch

Investments in real estate Schedule of investment in real estates (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Real Estate Properties [Line Items]
Land (related to rental properties)	$624,681	$553,388
Buildings and building improvements	6,171,504	5,714,673
Other improvements	192,128	174,147
Rental properties	6,988,313	6,442,208
Land available for development	683,101	658,546
Gross investments in real estate	8,228,855	7,682,376
Equity method of accounting - unconsolidated joint ventures	117,406	46,644
Gross investments in real estate - including unconsolidated joint ventures	8,346,261	7,729,020
Less: accumulated depreciation	-1,120,245	-952,106
Investments in real estate	7,226,016	6,776,914
Construction in progress ("CIP")/current value-added projects:
Real Estate Properties [Line Items]
CIP/current value-creation projects	557,441	581,622
Active development in North America | North America
Real Estate Properties [Line Items]
CIP/current value-creation projects	500,894	511,838
Active redevelopment in North America | North America
Real Estate Properties [Line Items]
CIP/current value-creation projects	42,482	8,856
Active development in Asia | Asia
Real Estate Properties [Line Items]
CIP/current value-creation projects	14,065	60,928
Near-term value-creation projects in North America (CIP)
Real Estate Properties [Line Items]
Land available for development	429,378	382,289
Land held for future development in North America
Real Estate Properties [Line Items]
Land available for development	253,723	253,314
Land held for future development in North America | North America
Real Estate Properties [Line Items]
Land available for development	175,175	176,063
Land held for future development in North America | Asia
Real Estate Properties [Line Items]
Land available for development	78,548	77,251
Land subject to sale negotiations
Real Estate Properties [Line Items]
Land available for development	0	22,943
50, 60, and 100 Binney Street Project [Member] | Near-term value-creation projects in North America (CIP) | North America
Real Estate Properties [Line Items]
Land available for development	321,907	284,672
Other Projects in North America [Member] | Near-term value-creation projects in North America (CIP) | North America
Real Estate Properties [Line Items]
Land available for development	$107,471	$97,617

Investments_in_real_estate_Acq

Investments in real estate Acquisitions (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	sqft
Business Acquisition [Line Items]
Area of Real Estate Property	18,729,282
Assumption of secured notes payable in connection with purchase of properties	$48,329,000	$0	$0
Operating properties acquired in 2014
Business Acquisition [Line Items]
Number of real estate properties	6
Area of Real Estate Property	405,353
Payments to acquired real estate property	115,000,000
Assumption of secured notes payable in connection with purchase of properties	48,300,000
Average percentage of occupied properties	100.00%
Land parcels acquired in 2014
Business Acquisition [Line Items]
Area of Real Estate Property	300,000
Payments to acquired real estate property	50,000,000
Number of Land Parcels	1
Lease negotiating percentage of occupancy	100.00%
Joint venture land parcels acquired in 2014 [Member]
Business Acquisition [Line Items]
Payments to acquired real estate property	$125,000,000
Number of Land Parcels	2

Investments_in_real_estate_Acq1

Investments in real estate Acquired leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Values of acquired leases
Value of intangible assets, net	($8,810,000)	($11,405,000)
Minimum lease payments to be received under the terms of the operating lease agreements, excluding expense reimbursements
2015	496,797,000
2016	488,626,000
2017	466,829,000
2018	423,234,000
2019	373,509,000
Thereafter	1,995,904,000
Total minimum lease payments to be received	4,244,899,000
Acquired Below Market Leases
Real Estate Properties [Line Items]
Amortization of intangible assets	2,800,000	3,300,000	3,200,000
Weighted average amortization period	2 years 3 months 18 days
Values of acquired leases
Value of intangible assets, gross	55,955,000	55,599,000
Accumulated amortization	-47,145,000	-44,194,000
Value of intangible assets, net	8,810,000	11,405,000
Estimated annual amortization
2015	2,861,000
2016	2,455,000
2017	2,251,000
2018	705,000
2019	209,000
Thereafter	329,000
Acquired-in-Place Leases
Real Estate Properties [Line Items]
Amortization of intangible assets	3,500,000	2,400,000	2,700,000
Weighted average amortization period	7 years 3 months 18 days
Values of acquired leases
Value of intangible assets, gross	51,395,000	48,189,000
Accumulated amortization	-32,123,000	-28,927,000
Value of intangible assets, net	19,272,000	19,262,000
Estimated annual amortization
2015	3,663,000
2016	2,709,000
2017	2,513,000
2018	2,377,000
2019	2,095,000
Thereafter	$5,915,000

Investments_in_real_estate_Rea

Investments in real estate Real estate asset sales (Details) (USD $)	12 Months Ended			36 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Sep. 30, 2014
	property			property	sqft
	sqft			sqft
Real Estate Properties [Line Items]
Number of properties sold	3			16
Area of Real Estate Property	18,729,282			18,729,282
Impairment of real estate	$51,675,000	$0	$13,450,000
Gain on sales of real estate - land parcels	6,403,000	4,824,000	1,864,000
Various
Real Estate Properties [Line Items]
Number of Land Parcels Sold	6
San Francisco, California
Real Estate Properties [Line Items]
Number of Land Parcels Sold	9
Number of Industrial Buildings Sold	7
Impairment of land parcels
Real Estate Properties [Line Items]
Impairment of real estate	24,700,000
661 University Avenue | CANADA
Real Estate Properties [Line Items]
Area of Real Estate Property					780,540
661 University Avenue | Impairment of real estate | CANADA
Real Estate Properties [Line Items]
Impairment of real estate	16,600,000
Percentage of Impairment of Real Estate related to Foreign Exchange Rate, Estimated Transfer Taxes, and Closing Costs	75.00%
500 Forbes Boulevard | San Francisco, California
Real Estate Properties [Line Items]
Area of Real Estate Property	155,685			155,685
Annualized Revenues minus Operating Expenses	5,500,000
Real Estate Project Yield	5.10%			5.10%
500 Forbes Boulevard | Impairment of real estate | San Francisco, California
Real Estate Properties [Line Items]
Impairment of real estate	9,600,000
Estimated Fair Value of Property, Less Cost to Sell	107,800,000			107,800,000
Income-producing assets | San Diego, California
Real Estate Properties [Line Items]
Number of properties sold	3
Proceeds from sale of real estate	7,400,000
Gain (loss) on disposal of properties recognized	1,800,000
Area of Real Estate Property	62,346			62,346
Land parcels | Various
Real Estate Properties [Line Items]
Proceeds from sale of real estate	48,400,000
Area of Real Estate Property	662,950			662,950
Gain on sales of real estate - land parcels	6,400,000
Land parcels | San Francisco, California
Real Estate Properties [Line Items]
Proceeds from sale of real estate	$31,000,000

Investments_in_real_estate_Dev

Investments in real estate Development and redevelopment projects (Details)	Dec. 31, 2014
	sqft
Real Estate Properties [Line Items]
Area of Real Estate Property	18,729,282
Development
Real Estate Properties [Line Items]
Number of real estate properties	7
Redevelopment
Real Estate Properties [Line Items]
Number of real estate properties	2
North America | Development
Real Estate Properties [Line Items]
Area of Real Estate Property	1,727,758
North America | Redevelopment
Real Estate Properties [Line Items]
Area of Real Estate Property	143,777

Investments_in_real_estate_Inv

Investments in real estate Investment in unconsolidated entity (Details) (USD $)	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Apr. 18, 2014	Dec. 31, 2013
	sqft
Schedule of Equity Method Investments [Line Items]
Area of Real Estate Property	18,729,282
Equity method of accounting - unconsolidated joint ventures	$117,406,000		$46,644,000
360 Longwood Avenue | Greater Boston
Schedule of Equity Method Investments [Line Items]
Area of Real Estate Property	413,536
Expected Total Joint Venture Development Cost	350,000,000
1455/1515 Third Street | San Francisco Bay Area
Schedule of Equity Method Investments [Line Items]
Area of Real Estate Property	422,980
Pre-leased RSF as a Percentage of Total RSF	100.00%
Equity method of accounting - unconsolidated joint ventures	68,300,000
Length of Lease	15 years
Longwood [Member] | Greater Boston
Schedule of Equity Method Investments [Line Items]
Pre-leased RSF as a Percentage of Total RSF	38.00%
Equity method of accounting - unconsolidated joint ventures	49,100,000
Longwood [Member] | Greater Boston | Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Equity interest percentage (in percent)	27.50%
Aggregate Commitments | Longwood [Member] | Greater Boston
Schedule of Equity Method Investments [Line Items]
Long-term Construction Loan	213,200,000
Outstanding Balance | Longwood [Member] | Greater Boston
Schedule of Equity Method Investments [Line Items]
Long-term Construction Loan	159,900,000
Remaining commitments | Longwood [Member] | Greater Boston
Schedule of Equity Method Investments [Line Items]
Long-term Construction Loan	53,300,000
1455/1515 Third Street | San Francisco Bay Area
Schedule of Equity Method Investments [Line Items]
Payments to acquired real estate property		$125,000,000
Alexandria Real Estate Equities, Inc. | 1455/1515 Third Street | San Francisco Bay Area
Schedule of Equity Method Investments [Line Items]
Equity interest percentage (in percent)	51.00%
Uber Technologies, Inc. | 1455/1515 Third Street | San Francisco Bay Area
Schedule of Equity Method Investments [Line Items]
Equity interest percentage (in percent)	49.00%

Investments_in_real_estate_Lan

Investments in real estate Land undergoing predevelopment and future development (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	sqft
Real Estate Properties [Line Items]
Area of Real Estate Property	18,729,282
Land available for development	$683,101	$658,546
Square Footage of Real Estate Property, Future Development	12,809,188
Land held for future development in North America
Real Estate Properties [Line Items]
Land available for development	253,700
Square Footage of Real Estate Property, Future Development	10,100,000
Near-term value-creation projects in North America (CIP)
Real Estate Properties [Line Items]
Area of Real Estate Property	2,715,792
Land available for development	$429,400
Near-term value-creation projects in North America (CIP) | Alexandria Center at Kendall Square
Real Estate Properties [Line Items]
Area of Real Estate Property	1,000,000

Investments_in_real_estate_Sal

Investments in real estate Sales of land parcels (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	sqft
Dispositions
Area of Real Estate Property	18,729,282
Gain (loss on) sale of properties	$6,403	$4,824	$1,864
Impairment of real estate	$51,675	$0	$13,450

Deferred_leasing_and_financing2

Deferred leasing and financing costs (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing costs, gross	$333,109	$293,879
Accumulated amortization	-174,194	-146,881
Deferred leasing costs, net	158,915	146,998
Deferred financing costs, gross	126,687	118,078
Accumulated amortization	-83,804	-72,418
Deferred financing costs, net	42,883	45,660
Deferred leasing and financing costs	$201,798	$192,658

Investments_Summary_of_Investm

Investments Summary of Investments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments [Abstract]
“Available-for-sale” marketable equity securities, at cost basis	$21,898	$2,879
Unrealized gains	53,625	2,177
Unrealized losses	-1,258	-587
“Available-for-sale” marketable equity securities, at fair value	74,265	4,469
Investments accounted for under cost method	162,124	135,819
Investments	$236,389	$140,288

Investments_Investment_Income_

Investments Investment Income (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments [Abstract]
Gross realized gains	$11,613	$7,050	$15,018
Gross realized losses	-9,287	-1,480	-2,637
Investment income	$2,326	$5,570	$12,381

Fair_value_measurements_Assets

Fair value measurements Assets and Liabilities on Recurring Basis (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy
Transfers in Fair Value Hierarchy	0	0
Assets:
Available-for-sale securities	$74,265	$4,469
Liabilities:
Interest rate swap agreements	909
Fair value measured on recurring basis
Assets:
Available-for-sale securities	74,265	4,469
Interest rate swap agreements		2,870
Liabilities:
Interest rate swap agreements	909	6,191
Fair value measured on recurring basis | Quoted Prices in Active Markets for Identical Assets
Assets:
Available-for-sale securities	74,265	4,469
Interest rate swap agreements		0
Liabilities:
Interest rate swap agreements	0	0
Fair value measured on recurring basis | Significant Other Observable Inputs
Assets:
Available-for-sale securities	0	0
Interest rate swap agreements		2,870
Liabilities:
Interest rate swap agreements	909	6,191
Fair value measured on recurring basis | Significant Unobservable Inputs
Assets:
Available-for-sale securities	0	0
Interest rate swap agreements		0
Liabilities:
Interest rate swap agreements	$0	$0

Fair_value_measurements_Book_a

Fair value measurements Book and Fair Values (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Summary of marketable securities, secured notes payable, unsecured senior line of credit, unsecured term loans, and unsecured senior convertible notes
“Available-for-sale” marketable equity securities, at fair value	$74,265	$4,469
Interest rate swap agreements	909
Book Value
Summary of marketable securities, secured notes payable, unsecured senior line of credit, unsecured term loans, and unsecured senior convertible notes
“Available-for-sale” marketable equity securities, at fair value	74,265	4,469
Interest rate swap agreements	0	2,870
Interest rate swap agreements	909	6,191
Secured notes payable	652,209	708,831
Unsecured senior notes payable	1,747,370	1,048,230
Unsecured senior line of credit	304,000	204,000
Unsecured senior bank term loans	975,000	1,100,000
Fair Value
Summary of marketable securities, secured notes payable, unsecured senior line of credit, unsecured term loans, and unsecured senior convertible notes
“Available-for-sale” marketable equity securities, at fair value	74,265	4,469
Interest rate swap agreements	0	2,870
Interest rate swap agreements	909	6,191
Secured notes payable	693,338	736,772
Unsecured senior notes payable	1,793,255	1,043,125
Unsecured senior line of credit	304,369	193,714
Unsecured senior bank term loans	$976,010	$1,099,897

Secured_and_unsecured_senior_d2

Secured and unsecured senior debt Summary of secured and unsecured senior debts (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Debt Instrument [Line Items]
Fixed rate/hedged variable rate	$3,101,351
Unhedged variable rate	577,228
Principal amount	3,678,579
Percentage of Total	100.00%
Total consolidated debt, effective interest	3.23%	[1]
Weighted Average Remaining Terms (in years)	5 years 7 months 6 days
Percentage of fixed rate/hedged total debt	84.00%
Percentage of unhedged floating rate total debt	16.00%
Secured notes payable maturing on 8/23/17
Debt Instrument [Line Items]
Weighted Average Interest Rate at End of Period	1.52%	[1]
Secured notes payable maturing on 06/1/16
Debt Instrument [Line Items]
Weighted Average Interest Rate at End of Period	1.56%	[1]
Secured notes payable maturing on 7/1/15
Debt Instrument [Line Items]
Weighted Average Interest Rate at End of Period	1.66%	[1]
Secured notes payable
Debt Instrument [Line Items]
Fixed rate/hedged variable rate	403,981
Unhedged variable rate	248,228
Principal amount	652,209
Percentage of Total	17.70%
Weighted Average Interest Rate at End of Period	4.59%	[1]
Weighted Average Remaining Terms (in years)	2 years 8 months 12 days
Senior Notes
Debt Instrument [Line Items]
Fixed rate/hedged variable rate	1,747,370
Unhedged variable rate	0
Principal amount	1,747,370
Percentage of Total	47.50%
Weighted Average Interest Rate at End of Period	3.98%
Weighted Average Remaining Terms (in years)	8 years 3 months 18 days
Line of Credit
Debt Instrument [Line Items]
Fixed rate/hedged variable rate	0
Unhedged variable rate	304,000
Principal amount	304,000
Percentage of Total	8.30%
Weighted Average Interest Rate at End of Period	1.27%	[1]
Weighted Average Remaining Terms (in years)	4 years
2016 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Fixed rate/hedged variable rate	350,000
Unhedged variable rate	25,000
Principal amount	375,000
Percentage of Total	10.20%
Weighted Average Interest Rate at End of Period	1.42%	[1]
Weighted Average Remaining Terms (in years)	1 year 7 months 6 days
2019 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Fixed rate/hedged variable rate	600,000
Unhedged variable rate	0
Principal amount	$600,000
Percentage of Total	16.30%
Weighted Average Interest Rate at End of Period	1.67%	[1]
Weighted Average Remaining Terms (in years)	4 years
LIBOR | Secured notes payable maturing on 8/23/17
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.35%
LIBOR | Secured notes payable maturing on 06/1/16
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.40%
LIBOR | Secured notes payable maturing on 7/1/15
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.50%
LIBOR | Line of Credit
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.10%	[2]
LIBOR | 2016 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.20%
LIBOR | 2019 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.20%
[1]	Represents the weighted average interest rate as of the end of the period plus the impact of debt premiums/discounts and our interest rate swap agreements. The weighted average interest rate excludes bank fees and amortization of loan fees.
[2]	In addition to the stated rate, the unsecured senior line of credit is subject to an annual facility fee of 0.20%, based on the aggregate commitments outstanding.

Secured_and_unsecured_senior_d3

Secured and unsecured senior debt Detail of secured and unsecured senior debt (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	$3,101,351
Unhedged variable rate	577,228
Principal amount	3,678,579
Total consolidated debt, effective interest	3.23%	[1]
Annual facility fee (as a percent)	0.20%
Future principal payments due on secured and unsecured debt
Total consolidated debt, effective interest	3.23%	[1]
Balloon payments	3,650,106
Principal amortization	28,473
2015
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	14,286
Unhedged variable rate	46,792
Principal amount	61,078
Future principal payments due on secured and unsecured debt
Balloon payments	52,532
Principal amortization	8,546
2016
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	591,418
Unhedged variable rate	44,343
Principal amount	635,761
Future principal payments due on secured and unsecured debt
Balloon payments	631,243
Principal amortization	4,518
2017
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	3,042
Unhedged variable rate	182,093
Principal amount	185,135
Future principal payments due on secured and unsecured debt
Balloon payments	182,093
Principal amortization	3,042
2018
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	3,253
Unhedged variable rate	0
Principal amount	3,253
Future principal payments due on secured and unsecured debt
Balloon payments	0
Principal amortization	3,253
2019
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	603,478
Unhedged variable rate	304,000
Principal amount	907,478
Future principal payments due on secured and unsecured debt
Balloon payments	904,000
Principal amortization	3,478
Thereafter
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	1,885,874
Unhedged variable rate	0
Principal amount	1,885,874
Future principal payments due on secured and unsecured debt
Balloon payments	1,880,238
Principal amortization	5,636
Secured notes payable
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	403,981
Unhedged variable rate	248,228
Principal amount	652,209
Stated interest rate (as a percent)	4.63%
Effective rate (as a percent)	4.59%	[1]
Future principal payments due on secured and unsecured debt
2015	61,404
2016	261,098
2017	185,485
2018	3,615
2019	3,853
Thereafter	136,754
Secured notes payable maturing on 6/1/15
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	5.64%
Effective rate (as a percent)	4.50%	[1]
Maturity date	1-Jun-15	[2]
Future principal payments due on secured and unsecured debt
2015	5,777
2016	0
2017	0
2018	0
2019	0
Thereafter	0
Principal amount	5,777
Secured notes payable maturing on 7/1/15
Summary of fixed rate/hedged and floating rate debt
Effective rate (as a percent)	1.66%	[1]
Maturity date	1-Jul-15	[2]
Future principal payments due on secured and unsecured debt
2015	46,792
2016	0
2017	0
2018	0
2019	0
Thereafter	0
Principal amount	46,792
CMBS maturing on 1/1/16
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	5.73%
Effective rate (as a percent)	5.73%	[1]
Maturity date	1-Jan-16	[2]
Future principal payments due on secured and unsecured debt
2015	1,815
2016	75,501
2017	0
2018	0
2019	0
Thereafter	0
Principal amount	77,316
CMBS maturing on 4/1/16
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	5.82%
Effective rate (as a percent)	5.82%	[1]
Maturity date	1-Apr-16	[2]
Future principal payments due on secured and unsecured debt
2015	988
2016	29,389
2017	0
2018	0
2019	0
Thereafter	0
Principal amount	30,377
Secured notes payable maturing on 4/15/16
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	5.74%
Effective rate (as a percent)	3.00%	[1]
Maturity date	15-Apr-16	[2]
Future principal payments due on secured and unsecured debt
2015	175
2016	6,916
2017	0
2018	0
2019	0
Thereafter	0
Principal amount	7,091
Secured notes payable maturing on 06/1/16
Summary of fixed rate/hedged and floating rate debt
Effective rate (as a percent)	1.56%	[1]
Maturity date	1-Jun-16	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	19,343
2017	0
2018	0
2019	0
Thereafter	0
Principal amount	19,343
CMBS maturing on 8/1/16
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	6.35%
Effective rate (as a percent)	6.35%	[1]
Maturity date	1-Aug-16	[2]
Future principal payments due on secured and unsecured debt
2015	2,652
2016	126,715
2017	0
2018	0
2019	0
Thereafter	0
Principal amount	129,367
Secured notes payable maturing on 1/20/17
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	2.15%
Effective rate (as a percent)	2.15%	[1]
Maturity date	20-Jan-17	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	0
2017	76,000
2018	0
2019	0
Thereafter	0
Principal amount	76,000
Secured notes payable maturing on 8/23/17
Summary of fixed rate/hedged and floating rate debt
Effective rate (as a percent)	1.52%	[1]
Maturity date	23-Aug-17	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	0
2017	106,093
2018	0
2019	0
Thereafter	0
Principal amount	106,093
Secured notes payable maturing on 4/1/20
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	7.75%
Effective rate (as a percent)	7.75%	[1]
Maturity date	1-Apr-20	[2]
Future principal payments due on secured and unsecured debt
2015	1,570
2016	1,696
2017	1,832
2018	1,979
2019	2,138
Thereafter	104,352
Principal amount	113,567
Secured notes payable maturing on 1/1/23
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	4.66%
Effective rate (as a percent)	4.66%	[1]
Maturity date	1-Jan-23	[2]
Future principal payments due on secured and unsecured debt
2015	1,403
2016	1,464
2017	1,540
2018	1,614
2019	1,692
Thereafter	31,674
Principal amount	39,387
Secured notes payable maturing on 6/1/37
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	6.50%
Effective rate (as a percent)	6.50%	[1]
Maturity date	1-Jun-37	[2]
Future principal payments due on secured and unsecured debt
2015	18
2016	19
2017	20
2018	22
2019	23
Thereafter	728
Principal amount	830
Unamortized Premiums
Future principal payments due on secured and unsecured debt
Unamortized Premium	269
Unamortized Premiums | 2015
Future principal payments due on secured and unsecured debt
Unamortized Premium	214
Unamortized Premiums | 2016
Future principal payments due on secured and unsecured debt
Unamortized Premium	55
Unamortized Premiums | 2017
Future principal payments due on secured and unsecured debt
Unamortized Premium	0
Unamortized Premiums | 2018
Future principal payments due on secured and unsecured debt
Unamortized Premium	0
Unamortized Premiums | 2019
Future principal payments due on secured and unsecured debt
Unamortized Premium	0
Unamortized Premiums | Thereafter
Future principal payments due on secured and unsecured debt
Unamortized Premium	0
Unsecured Debt
Summary of fixed rate/hedged and floating rate debt
Principal amount	3,026,370
Effective rate (as a percent)	2.94%	[1]
Unsecured Debt | 2015
Future principal payments due on secured and unsecured debt
2015	-326
Unsecured Debt | 2016
Future principal payments due on secured and unsecured debt
2016	374,663
Unsecured Debt | 2017
Future principal payments due on secured and unsecured debt
2017	-350
Unsecured Debt | 2018
Future principal payments due on secured and unsecured debt
2018	-362
Unsecured Debt | 2019
Future principal payments due on secured and unsecured debt
2019	903,625
Unsecured Debt | Thereafter
Future principal payments due on secured and unsecured debt
Thereafter	1,749,120
2016 Unsecured Senior Bank Term Loan
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	350,000
Unhedged variable rate	25,000
Principal amount	375,000
Effective rate (as a percent)	1.42%	[1]
Maturity date	31-Jul-16	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	375,000
2017	0
2018	0
2019	0
Thereafter	0
Principal amount	375,000
2019 Unsecured Senior Bank Term Loan
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	600,000
Unhedged variable rate	0
Principal amount	600,000
Effective rate (as a percent)	1.67%	[1]
Maturity date	3-Jan-19	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	0
2017	0
2018	0
2019	600,000
Thereafter	0
Principal amount	600,000
Line of Credit
Summary of fixed rate/hedged and floating rate debt
Fixed rate/hedged variable rate	0
Unhedged variable rate	304,000
Principal amount	304,000
Effective rate (as a percent)	1.27%	[1]
Maturity date	3-Jan-19	[2]
Annual facility fee (as a percent)	0.20%
Future principal payments due on secured and unsecured debt
2015	0
2016	0
2017	0
2018	0
2019	304,000
Thereafter	0
Principal amount	304,000
2.75% unsecured senior notes payable
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	2.75%
Effective rate (as a percent)	2.79%	[1]
Maturity date	15-Jan-20	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	0
2017	0
2018	0
2019	0
Thereafter	400,000
Principal amount	400,000
4.60% unsecured senior notes payable
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	4.60%
Effective rate (as a percent)	4.61%	[1]
Maturity date	1-Apr-22	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	0
2017	0
2018	0
2019	0
Thereafter	550,000
Principal amount	550,000
3.90% unsecured senior notes payable
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	3.90%
Effective rate (as a percent)	3.94%	[1]
Maturity date	15-Jun-23	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	0
2017	0
2018	0
2019	0
Thereafter	500,000
Principal amount	500,000
4.50% unsecured senior notes payable
Summary of fixed rate/hedged and floating rate debt
Stated interest rate (as a percent)	4.50%
Effective rate (as a percent)	4.51%	[1]
Maturity date	30-Jul-29	[2]
Future principal payments due on secured and unsecured debt
2015	0
2016	0
2017	0
2018	0
2019	0
Thereafter	300,000
Principal amount	300,000
Unamortized Discounts
Future principal payments due on secured and unsecured debt
Unamortized Discount	-2,630
Unamortized Discounts | 2015
Future principal payments due on secured and unsecured debt
Unamortized Discount	-326
Unamortized Discounts | 2016
Future principal payments due on secured and unsecured debt
Unamortized Discount	-337
Unamortized Discounts | 2017
Future principal payments due on secured and unsecured debt
Unamortized Discount	-350
Unamortized Discounts | 2018
Future principal payments due on secured and unsecured debt
Unamortized Discount	-362
Unamortized Discounts | 2019
Future principal payments due on secured and unsecured debt
Unamortized Discount	-375
Unamortized Discounts | Thereafter
Future principal payments due on secured and unsecured debt
Unamortized Discount	($880)
[1]	Represents the weighted average interest rate as of the end of the period plus the impact of debt premiums/discounts and our interest rate swap agreements. The weighted average interest rate excludes bank fees and amortization of loan fees.
[2]	Includes any extension options that we control.

Secured_and_unsecured_senior_d4

Secured and unsecured senior debt Unsecured senior notes payable (Details) (USD $)	12 Months Ended			0 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 07, 2013	Feb. 29, 2012
Debt Instrument [Line Items]
Repayments of Unsecured Debt	$125,000,000	$250,000,000	$250,000,000
Gains (Losses) on Extinguishment of Debt	-525,000	-1,992,000	-2,225,000
Ownership interest in subsidiary (as a percent)	100.00%
2016 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Repayments of Unsecured Debt		250,000,000
2012 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Repayments of Unsecured Debt			250,000,000
Gains (Losses) on Extinguishment of Debt			600,000
Line of Credit
Debt Instrument [Line Items]
Gains (Losses) on Extinguishment of Debt			1,600,000
Senior Notes | 2.75% and 4.50% unsecured senior notes payable
Debt Instrument [Line Items]
Debt Instrument, Face Amount	700,000,000
Stated interest rate (as a percent)	3.50%
Senior Notes | 2.75% unsecured senior notes payable
Debt Instrument [Line Items]
Debt Instrument, Face Amount	400,000,000
Stated interest rate (as a percent)	2.75%
Debt Instrument, Issuance Price as Percentage of Principal Amount	99.79%
Yield rate (as a percent)	2.79%
Senior Notes | 4.50% unsecured senior notes payable
Debt Instrument [Line Items]
Debt Instrument, Face Amount	300,000,000
Stated interest rate (as a percent)	4.50%
Debt Instrument, Issuance Price as Percentage of Principal Amount	99.91%
Yield rate (as a percent)	4.51%
Senior Notes | 3.90% unsecured senior notes payable
Debt Instrument [Line Items]
Debt Instrument, Face Amount				500,000,000
Stated interest rate (as a percent)				3.90%
Debt Instrument, Issuance Price as Percentage of Principal Amount				99.71%
Yield rate (as a percent)				3.94%
Maturity date		15-Jun-23
Senior Notes | 4.60% unsecured senior notes payable
Debt Instrument [Line Items]
Debt Instrument, Face Amount					550,000,000
Stated interest rate (as a percent)					4.60%
Debt Instrument, Issuance Price as Percentage of Principal Amount					99.92%
Yield rate (as a percent)					4.61%
Senior Notes | 2016 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Repayments of Unsecured Debt	125,000,000	150,000,000
Gains (Losses) on Extinguishment of Debt		560,000
Senior Notes | Line of Credit
Debt Instrument [Line Items]
Repayments of Unsecured Debt	$569,000,000

Secured_and_unsecured_senior_d5

Secured and unsecured senior debt Unsecured senior line of credit and unsecured senior bank term loans (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Principal amount	$3,678,579
Repayments of Unsecured Debt	125,000		250,000	250,000
Gains (Losses) on Extinguishment of Debt	-525		-1,992	-2,225
Unsecured senior line of credit	304,000		204,000
Annual facility fee (as a percent)	0.20%
Line of Credit
Debt Instrument [Line Items]
Principal amount	304,000
Gains (Losses) on Extinguishment of Debt				1,600
2012 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Repayments of Unsecured Debt				250,000
Gains (Losses) on Extinguishment of Debt				600
2016 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Repayments of Unsecured Debt			250,000
Unsecured bank debt
Debt Instrument [Line Items]
Principal amount	1,280,000
2016 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Principal amount	375,000
2016 Unsecured Senior Bank Term Loan | LIBOR
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.20%
2019 Unsecured Senior Bank Term Loan
Debt Instrument [Line Items]
Principal amount	600,000
2019 Unsecured Senior Bank Term Loan | LIBOR
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.20%
Line of Credit
Debt Instrument [Line Items]
Principal amount	$304,000
Annual facility fee (as a percent)	0.20%
Line of Credit | Federal Funds Rate
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Line of Credit | Eurodollar
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
Line of Credit | LIBOR
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.10%	[1]
[1]	In addition to the stated rate, the unsecured senior line of credit is subject to an annual facility fee of 0.20%, based on the aggregate commitments outstanding.

Secured_and_unsecured_senior_d6

Secured and unsecured senior debt Summary of financial covenants (Details)	Dec. 31, 2014
Unsecured senior notes payable
Debt Instrument [Line Items]
Total Debt to Total Assets (as a percent)	60.00%
Secured Debt to Total Assets (as a percent)	40.00%
Debt Instrument, EBITDA to Interest Expense Ratio	150.00%
Unencumbered Total Asset Value to Unsecured Debt (as a percent)	150.00%
Unsecured bank debt
Debt Instrument [Line Items]
Secured Debt to Total Assets (as a percent)	45.00%
Maximum Ratio of Indebtedness to Total Assets Covenant Compliance	60.00%
Fixed charge coverage ratio	150.00%
Maximum Unsecured Leverage Ratio Covenant Compliance	60.00%
Minimum Unsecured Interest Coverage Ratio Covenant Compliance	1.5

Secured_and_unsecured_senior_d7

Secured and unsecured senior debt Interest expense (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Interest expense incurred
Gross interest	$126,404	$128,567		$131,935
Capitalized interest	-47,105	-60,615		-62,751
Interest expense	$79,299	$67,952	[1]	$69,184	[1]
[1]	Includes interest expense related to and classified in income from discontinued operations in the accompanying consolidated statements of income.

Secured_and_unsecured_senior_d8

Secured and unsecured senior debt Repayment of secured notes payable (Details) (USD $)	0 Months Ended
	Jan. 31, 2014	Apr. 02, 2014	Aug. 01, 2014
Secured notes payable from insurance co. maturing on 4/1/14 | Alexandria Technology Square
Debt Instrument [Line Items]
Principal amount	$208,700,000
Effective rate (as a percent)	5.59%
Contributions by redeemable noncontrolling interests	20,900,000
Secured debt from bank maturing on 7/1/14 | San Diego
Debt Instrument [Line Items]
Principal amount		6,400,000
Effective rate (as a percent)		4.88%
Secured notes payable from bank maturing on 11/1/14 | San Diego
Debt Instrument [Line Items]
Principal amount			$7,400,000
Effective rate (as a percent)			4.00%

Secured_and_unsecured_senior_d9

Secured and unsecured senior debt Secured construction loans (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
	Extension_Option
Secured notes payable maturing on 8/23/17
Debt Instrument [Line Items]
Maturity date	23-Aug-17	[1]
Principal amount	$106,093,000
Number of Extensions	1
Secured notes payable maturing on 06/1/16
Debt Instrument [Line Items]
Maturity date	1-Jun-16	[1]
Principal amount	19,343,000
Number of Extensions	2
Secured notes payable maturing on 7/1/15
Debt Instrument [Line Items]
Maturity date	1-Jul-15	[1]
Principal amount	46,792,000
Number of Extensions	2
Construction Loans
Debt Instrument [Line Items]
Principal amount	172,228,000
Remaining Commitments	169,172,000
Total Aggregate Commitments	341,400,000
San Francisco Bay Area | Construction Loans | Secured notes payable maturing on 7/1/15
Debt Instrument [Line Items]
Maturity date	1-Jul-15	[2]
Principal amount	46,792,000
Remaining Commitments	8,208,000
Total Aggregate Commitments	55,000,000
San Francisco Bay Area | Construction Loans | Secured notes payable maturing on 06/1/16
Debt Instrument [Line Items]
Maturity date	1-Jun-16	[3]
Principal amount	19,343,000
Remaining Commitments	16,657,000
Total Aggregate Commitments	36,000,000
Greater Boston | Construction Loans | Secured notes payable maturing on 8/23/17
Debt Instrument [Line Items]
Maturity date	23-Aug-17	[4]
Principal amount	106,093,000
Remaining Commitments	144,307,000
Total Aggregate Commitments	$250,400,000
[1]	Includes any extension options that we control.
[2]	We have two, one-year options to extend the stated maturity date to July 1, 2017, subject to certain conditions.
[3]	We have two, one-year options to extend the stated maturity date to June 1, 2018, subject to certain conditions.
[4]	We have a one-year option to extend the stated maturity date to August 23, 2018, subject to certain conditions.

Interest_rate_swap_agreements_2

Interest rate swap agreements (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments and Hedging Activities Disclosure [Abstract]
The percentage of effectiveness of interest rate swap agreements	100.00%	100.00%	100.00%
Interest rate swap hedge ineffectiveness recognized in earnings	$0	$0	$0
Cash flow hedge loss to be reclassified within twelve months	1,100,000
Collateral obligation requirements	0
Interest rate swap agreements	909,000
Assets Needed for Immediate Settlement, Aggregate Fair Value	$916,000

Interest_rate_swap_agreements_3

Interest rate swap agreements Outstanding interest rate swap (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Interest rate hedge agreements
Fair Values	-909
Effective Portion of Interest Rate Cash Flow Hedge at Fiscal Year End	950,000
Notional Amount in Effect as of 2015	500,000
Notional Amount in Effect as of 2016	500,000
Interest Rate Hedge .23 Percent Transaction Date March 2015
Interest rate hedge agreements
Number of Interest Rate Derivatives Held	2
Interest Pay Rate (as a percent)	0.23%
Fair Values	-43
Effective Portion of Interest Rate Cash Flow Hedge at Fiscal Year End	250,000
Notional Amount in Effect as of 2015	0
Notional Amount in Effect as of 2016	0
Interest Rate Hedge .21 Percent Transaction Date March 2014 [Member]
Interest rate hedge agreements
Number of Interest Rate Derivatives Held	4
Interest Pay Rate (as a percent)	0.21%
Fair Values	-22
Effective Portion of Interest Rate Cash Flow Hedge at Fiscal Year End	200,000
Notional Amount in Effect as of 2015	0
Notional Amount in Effect as of 2016	0
Transaction date December 2014, interest pay rate 0.527%
Interest rate hedge agreements
Number of Interest Rate Derivatives Held	3
Interest Pay Rate (as a percent)	0.53%
Fair Values	-625
Effective Portion of Interest Rate Cash Flow Hedge at Fiscal Year End	500,000
Notional Amount in Effect as of 2015	500,000
Notional Amount in Effect as of 2016	0
Transaction date March 2016, interest pay rate 1.406%
Interest rate hedge agreements
Number of Interest Rate Derivatives Held	3
Interest Pay Rate (as a percent)	1.40%
Fair Values	-219
Effective Portion of Interest Rate Cash Flow Hedge at Fiscal Year End	0
Notional Amount in Effect as of 2015	0
Notional Amount in Effect as of 2016	500,000
Unsecured Bank Term Loans [Member] | Minimum
Interest rate hedge agreements
Debt Instrument, Basis Spread on Variable Rate	1.20%
Unsecured Senior Line of Credit | Minimum
Interest rate hedge agreements
Debt Instrument, Basis Spread on Variable Rate	1.10%

Accounts_payable_accrued_expen2

Accounts payable, accrued expenses, and tenant security deposits (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Accounts payable and accrued expenses	$127,828	$98,037
Accrued construction	91,110	78,098
Acquired below market leases	8,810	11,405
Conditional asset retirement obligations	9,108	7,386
Deferred rent liability	36,231	35,134
Interest rate swap liabilities	909	6,191
Prepaid rent and tenant security deposits	193,699	188,241
Other liabilities	21,390	10,850
Accounts payable, accrued expenses, and tenant security deposits	$489,085	$435,342

Earnings_per_share_Details

Earnings per share (Details) (USD $)	3 Months Ended																12 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Earnings per share
Income from continuing operations																	$99,142,000		$134,525,000		$94,848,000
Gain on sales of real estate - land parcels																	6,403,000		4,824,000		1,864,000
Net income attributable to noncontrolling interests																	-5,204,000		-4,032,000		-3,402,000
Dividends on preferred stock																	-25,698,000		-25,885,000		-27,328,000
Preferred stock redemption charge																	-1,989,000		0		-5,978,000
Net income attributable to unvested restricted stock awards																	1,774,000		1,581,000		1,190,000
Income from continuing operations attributable to Alexandria Real Estate Equities, Inc.'s common stockholders - basic and diluted																	70,880,000		107,851,000		58,814,000
(Loss) income from discontinued operations, net																	1,233,000	[1]	900,000	[1]	8,816,000	[1]
Net income attributable to Alexandria’s common stockholders																	72,113,000		108,751,000		67,630,000
Weighted average shares of common stock outstanding – basic and diluted																	71,170		68,038		62,160
Earnings per share attributable to Alexandria Real Estate Equities, Inc.'s common stockholders - basic and diluted:
Continuing operations																	$0.99		$1.59		$0.95
Discontinued operations																	$0.02		$0.01		$0.14
Earnings per share – basic and diluted	($0.23)	[2],[3]	$0.39	[2]	$0.39	[2]	$0.46	[2]	$0.51	[2]	$0.35	[2]	$0.38	[2]	$0.36	[2]	$1.01		$1.60		$1.09
Convertible Notes Outstanding [Member]
Debt Instrument [Line Items]
Convertible Notes Payable	$0																$0
[1]	Income from discontinued operations includes the results of operations of three properties that were disposed of during the year ended December 31, 2014, and the results of one property which was classified as “held for sale” prior to adoption of the new ASU and included as discontinued operations as of December 31, 2014, as well as the results of operations (prior to disposition) and gain (loss) on sale of real estate attributable to 16 properties sold during the period from January 1, 2012, to December 31, 2014.
[2]	(1)Quarterly earnings per common share amounts may not total to the annual amounts due to rounding and due to the increase in the weighted average shares of common stock outstanding.
[3]	(2)Results for the fourth quarter of 2014 include an aggregate net loss of $46.2 million, or $0.65 per share, related to impairments of real estate and a preferred stock redemption charge, partially offset by gains on sales of real estate. See further discussion of impairments of real estate and gains on real estate in Note 3 – “Investments in Real Estate.

Income_taxes_Details

Income taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Minimum percentage of taxable income to be distributed	90.00%
The Company generally distributes this percentage or more of its taxable income	100.00%
Unrecognized Tax Benefits	$0

Income_taxes_Reconciliation_of

Income taxes Reconciliation of net income to taxable income (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Income Tax Disclosure [Abstract]
Net income	$106,778,000	$140,249,000		$105,528,000
Net income attributable to noncontrolling interests	-5,204,000	-4,032,000		-3,402,000
Rental revenue recognition		16,800,000		11,607,000
Depreciation and amortization		12,936,000		15,501,000
Stock-based compensation		13,754,000		11,488,000
Interest expense		356,000		-8,068,000
Sales of property		-14,284,000		394,000
Impairments		0		13,450,000
Other		10,284,000		2,268,000
Taxable income, before dividend deduction		176,063,000		148,766,000
Dividend deduction necessary to eliminate taxable income (1)		-176,063,000	[1]	-148,766,000	[1]
Estimated income subject to federal income tax		0		0
Distributions paid		$195,000,000		$154,300,000
[1]	Total common stock and preferred stock dividend distributions paid were approximately $195.0 million and $154.3 million for the years ended December 31, 2013 and 2012, respectively.

Income_taxes_Income_Tax_Treatm

Income taxes Income Tax Treatment of Distributions (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Common Stock
Income Tax Treatment of Distributions and Dividends [Line Items]
Ordinary income	91.80%	85.90%	85.00%
Return of capital	8.20%	11.60%	4.60%
Capital gains	0.00%	2.50%	10.40%
Total	100.00%	100.00%	100.00%
Dividends declared	$2.88	$2.61	$2.09
Series C Preferred Stock
Income Tax Treatment of Distributions and Dividends [Line Items]
Ordinary income			89.10%
Return of capital			0.00%
Capital gains			10.90%
Total			100.00%
Dividends declared			$0.52
Series D Convertible Preferred Stock
Income Tax Treatment of Distributions and Dividends [Line Items]
Ordinary income	100.00%	97.20%	89.10%
Return of capital	0.00%	0.00%	0.00%
Capital gains	0.00%	2.80%	10.90%
Total	100.00%	100.00%	100.00%
Dividends declared	$1.75	$1.75	$1.75
Series E Cumulative Redeemable Preferred Stock
Income Tax Treatment of Distributions and Dividends [Line Items]
Ordinary income	100.00%	97.20%	89.10%
Return of capital	0.00%	0.00%	0.00%
Capital gains	0.00%	2.80%	10.90%
Total	100.00%	100.00%	100.00%
Dividends declared	$1.61	$1.61	$1.34

Commitments_and_contingencies_2

Commitments and contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Lease
	Tenant
	property
	Parcel
Concentration Risk [Line Items]
Discretionary profit sharing contributions subject to statutory limitations	$1,800,000	$1,600,000	$1,400,000
FDIC insurance coverage	250,000
Largest aggregate notional amount in effect at any single point	250,000,000
Number of leases held	562
Number of client tenants	441
Rentable Square Feet Properties Number	193
Remaining aggregate costs under contracts, under terms of leases	525,000,000
Letters of credit and performance obligations	13,600,000
Land available for development	683,101,000	658,546,000
Operating Leases, Rent Expense, Net	13,400,000	11,400,000	10,600,000
Number of properties under terms of ground leases	28
Number of land development parcels under terms of ground leases	2
Term of operating lease obligation related to office leases	5 years
Number of ground leases related to operating property that expires in 2036	1
Net book value	10,000,000
Single Tenant | Lessee Concentration
Concentration Risk [Line Items]
Number of Single Tenant Properties	87
Single Tenant Properties as Percentage of Total Properties	45.00%
Three Largest Tenants | Lessee Concentration | Annualized Base Rent
Concentration Risk [Line Items]
Number of largest tenants	3
Concentration risk, percentage	14.60%
First Largest Tenant | Lessee Concentration | Annualized Base Rent
Concentration Risk [Line Items]
Concentration risk, percentage	6.10%
Second Largest Tenant | Lessee Concentration | Annualized Base Rent
Concentration Risk [Line Items]
Concentration risk, percentage	4.90%
Third Largest Tenant | Lessee Concentration | Annualized Base Rent
Concentration Risk [Line Items]
Concentration risk, percentage	3.60%
Minimum
Concentration Risk [Line Items]
Expected period of payment obligation	1 year
Term of ground lease obligation	40 years
Maximum
Concentration Risk [Line Items]
Expected period of payment obligation	2 years
Term of ground lease obligation	100 years
Funding Investments
Concentration Risk [Line Items]
Fund commitment on certain investments	75,000,000
Project Development Agreements
Concentration Risk [Line Items]
Land available for development	22,100,000
Area of land that is under construction commitment obligations	300,000
Minimum cost per square foot | Project Development Agreements
Concentration Risk [Line Items]
Land available for development	0
Maximum cost per square foot | Project Development Agreements
Concentration Risk [Line Items]
Land available for development	$0

Commitments_and_contingencies_3

Commitments and contingencies Future Minimum Lease Obligations Schedule (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Office Leases
2015	$1,501
2016	1,490
2017	1,561
2018	1,632
2019	2,115
Thereafter	0
Total	8,299
Ground Leases
2015	9,828
2016	10,436
2017	10,506
2018	10,595
2019	8,978
Thereafter	616,739
Total	667,082
Total
2015	11,329
2016	11,926
2017	12,067
2018	12,227
2019	11,093
Thereafter	616,739
Total	$675,381

Stockholders_equity_Details

Stockholders' equity (Details) (USD $)	12 Months Ended			0 Months Ended	1 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 18, 2014	Apr. 30, 2008	Apr. 30, 2012
Issuances of common stock
Preferred stock redemption charge	$1,989	$0	$5,978
Preferred stock, shares authorized	100,000,000
Number of shares issued and outstanding	14,700,000
Number of "excess stock" authorized (in shares)	200,000,000
Number of excess stock authorized issued and outstanding (in shares)	0
Series D Convertible Preferred Stock
Issuances of common stock
Preferred stock redemption charge	2,000
Series D Preferred Stock, Shares Outstanding	9,486,500	10,000,000
Payment of quarterly dividends in arrears at an annual rate (in dollars per share)					$1.75
Redemption price per share	$25			$27.98		$25
Number of share issued and outstanding				513,500
Stock Redeemed or Called During Period, Value	14,414			14,400
Percentage of the closing sale price per share of the entity's common stock that the then-applicable conversion price must exceed in order for the shares to be automatically converted					150.00%
Minimum number of trading days within 30 consecutive trading days during which the closing sale price per share of entity's common stock equals or exceeds the then-applicable conversion price for the shares to be automatically converted					20 days
Number of consecutive trading day period within which the closing sale price per share of entity's common stock equals or exceeds the then-applicable conversion price for at least 20 trading days for the shares to be automatically converted					30 days
Conversion rate at a option of holders (in shares)					0.2477
Conversion rate which is equivalent to an initial conversion price per share of common stock (in dollars per share)					$101
Conversion rate dividend adjustment per quarter (in dollars per share)					$0.78
Conversion rate (in shares)	0.248
Conversion price (in dollars per share)	$100.81
Preferred stock, shares authorized	10,000,000	10,000,000
Number of shares issued and outstanding	9,486,500	10,000,000
Write-off of issuance costs [Member] | Series D Convertible Preferred Stock
Issuances of common stock
Preferred stock redemption charge	($412)

Stockholders_equity_Accumulate

Stockholders' equity Accumulated other comprehensive loss (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Balance as of December 31, 2013	($36,204)
Other comprehensive income (loss) before reclassifications	28,601
Amounts reclassified from other comprehensive income	6,305
Amounts attributable to noncontrolling interest	670
Total other comprehensive (loss) income	35,576
Balance as of December 31, 2014	-628
Unrealized Gain on Marketable Securities
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Balance as of December 31, 2013	1,590
Other comprehensive income (loss) before reclassifications	51,135
Amounts reclassified from other comprehensive income	-358
Amounts attributable to noncontrolling interest	0
Total other comprehensive (loss) income	50,777
Balance as of December 31, 2014	52,367
Unrealized Loss on Interest Rate Swap Agreements
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Balance as of December 31, 2013	-3,321
Other comprehensive income (loss) before reclassifications	-4,459
Amounts reclassified from other comprehensive income	6,871
Amounts attributable to noncontrolling interest	0
Total other comprehensive (loss) income	2,412
Balance as of December 31, 2014	-909
Unrealized Loss on Foreign Currency Translation
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Balance as of December 31, 2013	-34,473
Other comprehensive income (loss) before reclassifications	-18,075
Amounts reclassified from other comprehensive income	-208
Amounts attributable to noncontrolling interest	670
Total other comprehensive (loss) income	-17,613
Balance as of December 31, 2014	($52,086)

Sharebased_compensation_Schedu

Share-based compensation Schedule of stock option activity (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	2,800,000
Number of additional awards authorized for issuance under an established share-based compensation plan	1,400,000
Shares reserved for granting of future options and share awards	3,093,382
Employee Stock Option
Stock Options
Outstanding at beginning of year	0	0	3,600
Granted	0	0	0
Exercised			-3,600
Forfeited			0
Outstanding at end of year	0	0	0
Exercisable intrinsic value			$94,968

Sharebased_compensation_Detail

Share-based compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation [Abstract]
Total compensation recognized for awards, net of capitalization	$13,996,000	$15,552,000	$14,160,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	2 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate	20.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	3.40%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	0.67%
Stock Award
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning balance (in shares)	569,773	561,068	550,763
Number of shares granted	416,954	338,915	310,240
Number of shares vested	-286,681	-323,594	-297,669
Number of shares forfeited	-25,077	-6,616	-2,266
Outstanding, ending balance (in shares)	674,969	569,773	561,068
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighed average grant date fair value per share, outstanding beginning balance	$68.54	$73.37	$71.04
Weighed average grant date fair value per share, granted	$72.25	$63.74	$72.85
Weighed average grant date fair value per share, vested	$72.91	$71.78	$68.52
Weighed average grant date fair value per share, forfeited	$55.72	$72.96	$74.30
Weighed average grant date fair value per share, outstanding ending balance	$69.46	$68.54	$73.37
Share-based Compensation [Abstract]
Total fair value of share awards vested	20,903,000	23,228,000	20,396,000
Total compensation recognized for awards, net of capitalization	13,996,000	15,552,000	14,160,000
Capitalized stock compensation	7,583,000	8,193,000	7,768,000
Unrecognized compensation related to nonvested share awards	$39,600,000
Unrecognized compensation recognition period (in years)	3 years
Weighted average period recognition period for unrecognized compensation	14 months

Noncontrolling_interests_Detai

Noncontrolling interests (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Noncontrolling interests
Income from continuing operations attributable to Alexandria	$100,341		$135,317		$93,310
Income from discontinued operations	$1,233	[1]	$900	[1]	$8,816	[1]
Noncontrolling Interests
Noncontrolling interests
Number of Real Estate Projects Subject to Ownership from Noncontrolling Interest	4
[1]	Income from discontinued operations includes the results of operations of three properties that were disposed of during the year ended December 31, 2014, and the results of one property which was classified as “held for sale” prior to adoption of the new ASU and included as discontinued operations as of December 31, 2014, as well as the results of operations (prior to disposition) and gain (loss) on sale of real estate attributable to 16 properties sold during the period from January 1, 2012, to December 31, 2014.

Discontinued_operationsassets_2

Discontinued operations/assets held for sale (Details) (USD $)	12 Months Ended						36 Months Ended	1 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2014	Jan. 31, 2015
	property						property	property
	sqft						sqft	sqft
Net assets of discontinued operations
Properties held for sale	$173,706		$7,644				$173,706
Other assets	10,147		103				10,147
Total assets	183,853		7,747				183,853
Total liabilities	-6,044		-266				-6,044
Net assets held for sale	177,809		7,481				177,809
Income from discontinued operations, net
Total revenues	0		4,657		36,283
Operating expenses	-605		-1,981		-11,313
Total revenues less operating expenses from discontinued operations	-605		2,676		24,970
Depreciation and Amortization, Discontinued Operations	0		-1,655		-6,318
Loss (gain) on sale of real estate	1,838		-121		1,564
Impairment of real estate	0		0		-11,400
Income from discontinued operations	1,233	[1]	900	[1]	8,816	[1]
Income from assets held for sale not qualifying as discontinued operations [Abstract]
Total revenues	9,661		9,975		9,604
Operating expenses	-3,760		-3,525		-3,156
Total revenues less operating expenses from assets classified as held for sale, not qualifying as discontinued operations	5,901		6,450		6,448
Depreciation expense	-7,005		-7,189		-7,103
Impairment of real estate	-26,975		0		0
Loss from assets classified as held for sale, not qualifying as discontinued operations	($28,079)	[2]	($739)	[2]	($655)	[2]
Number of operating properties classified as held for sale	1
Assets Held for Sale, Number of Properties	5						5
Number of properties sold	3						16
Disposal Group Including Assets Held for Sale, Not Qualifying as Discontinued Operations, Number of Properties	4
Disposal Group Including Assets Held for Sale, Not Qualifying as Discontinued Operations, Area of Real Estate	1,036,585						1,036,585
Assets held for sale sold in January 2015 | Subsequent Event
Income from assets held for sale not qualifying as discontinued operations [Abstract]
Disposal Group Including Assets Held for Sale, Not Qualifying as Discontinued Operations, Properties Sold Number								2
Disposal Group Including Assets Held for Sale, Not Qualifying as Discontinued Operations, Area of Real Estate								802,399
[1]	Income from discontinued operations includes the results of operations of three properties that were disposed of during the year ended December 31, 2014, and the results of one property which was classified as “held for sale” prior to adoption of the new ASU and included as discontinued operations as of December 31, 2014, as well as the results of operations (prior to disposition) and gain (loss) on sale of real estate attributable to 16 properties sold during the period from January 1, 2012, to December 31, 2014.
[2]	Includes the results of operations of four properties with an aggregate 1,036,585 RSF that were classified as “held for sale” as of December 31, 2014, but do not qualify for classification as discontinued operations. In January 2015, we subsequently sold two of these properties with an aggregate 802,399 RSF. For additional information, refer to the section titled “Basis of Presentation and Summary of Significant Accounting Policies” in Note 2 to our audited consolidated financial statements under Item 15 of this Report. As of December 31, 2013, and 2012, we did not have any assets classified as “held for sale”, not qualifying as discontinued operations.

Quarterly_financial_data_unaud2

Quarterly financial data (unaudited) (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$188,674,000		$185,615,000		$176,402,000		$176,186,000		$168,823,000		$158,315,000		$153,930,000		$150,083,000		$726,877,000	$631,151,000	$574,497,000
Net income attributable to Alexandria Real Estate Equities, Inc.'s common stockholders	-16,154,000		27,626,000		27,932,000		32,709,000		36,247,000		24,579,000		25,483,000		22,442,000		72,113,000	108,751,000	67,630,000
Earnings per share attributable to Alexandria’s common stockholders – basic and diluted:
Basic and diluted (1)	($0.23)	[1],[2]	$0.39	[1]	$0.39	[1]	$0.46	[1]	$0.51	[1]	$0.35	[1]	$0.38	[1]	$0.36	[1]	$1.01	$1.60	$1.09
Net loss related to impairments of real estate and a preferred stock redemption charge, partially offset by gains on sales of real estate	$46,200,000
Net loss related to impairments of real estate and a preferred stock redemption charge, partially offset by gains on sales of real estate, per share	$0.65
[1]	(1)Quarterly earnings per common share amounts may not total to the annual amounts due to rounding and due to the increase in the weighted average shares of common stock outstanding.
[2]	(2)Results for the fourth quarter of 2014 include an aggregate net loss of $46.2 million, or $0.65 per share, related to impairments of real estate and a preferred stock redemption charge, partially offset by gains on sales of real estate. See further discussion of impairments of real estate and gains on real estate in Note 3 – “Investments in Real Estate.

Subsequent_events_Narrative_De

Subsequent events Narrative (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 21, 2015	Jan. 07, 2015
	Tenant			sqft
	sqft
Subsequent Event [Line Items]
Area of Real Estate Property	18,729,282
Number of client tenants	441
Assumption of secured notes payable in connection with purchase of properties	$48,329,000	$0	$0
Alexandria Technology Square | Subsequent Event
Subsequent Event [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners				10.00%
Number of Installment Payments				0
Payments to Acquire Additional Interest in Subsidiaries				108,300,000
640 Memorial Drive | Subsequent Event
Subsequent Event [Line Items]
Payments to acquired real estate property				176,500,000
Area of Real Estate Property				225,504
Number of client tenants				2
Assumption of secured notes payable in connection with purchase of properties				82,000,000
Operating properties acquired in 2014
Subsequent Event [Line Items]
Payments to acquired real estate property	115,000,000
Area of Real Estate Property	405,353
Average percentage of occupied properties	100.00%
Assumption of secured notes payable in connection with purchase of properties	48,300,000
Operating properties acquired in 2014 | Subsequent Event
Subsequent Event [Line Items]
Average percentage of occupied properties				100.00%
Secured debt maturing in 2023 [Member] | 640 Memorial Drive | Subsequent Event
Subsequent Event [Line Items]
Stated interest rate (as a percent)				3.93%
Alexandria Technology Square | Subsequent Event
Subsequent Event [Line Items]
Area of Real Estate Property				1,200,000
Land and Land Improvements [Member] | CANADA | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of real estate					54,100,000
Installment Payment | Alexandria Technology Square | Subsequent Event
Subsequent Event [Line Items]
Payments to Acquire Additional Interest in Subsidiaries				$54,000,000

Condensed_consolidating_financ2

Condensed consolidating financial information Balance Sheet (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Assets
Investments in real estate	$7,226,016	$6,776,914
Cash and cash equivalents	86,011	57,696	140,971	78,539
Restricted cash	26,884	27,709
Tenant receivables	10,548	9,918
Deferred rent	234,124	190,425
Deferred leasing and financing costs	201,798	192,658
Investments	236,389	140,288
Investments in and advances to affiliates	0	0
Other assets	114,266	134,156
Total assets	8,136,036	7,529,764
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	652,209	708,831
Unsecured senior notes payable	1,747,370	1,048,230
Unsecured senior line of credit	304,000	204,000
Unsecured senior bank term loans	975,000	1,100,000
Accounts payable, accrued expenses, and tenant security deposits	489,085	435,342
Dividends payable	58,814	54,420
Total liabilities	4,226,478	3,550,823
Redeemable noncontrolling interests	14,315	14,444
Alexandria's stockholders' equity	3,828,439	3,916,789
Noncontrolling interests	66,804	47,708
Total equity	3,895,243	3,964,497	3,488,494	3,416,859
Total liabilities, noncontrolling interests, and equity	8,136,036	7,529,764
Alexandria Real Estate Equities, Inc. (Issuer)
Assets
Investments in real estate	0	0
Cash and cash equivalents	52,491	14,790	98,567	10,608
Restricted cash	67	55
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing and financing costs	35,462	36,901
Investments	0	0
Investments in and advances to affiliates	6,874,866	6,299,551
Other assets	19,461	20,226
Total assets	6,982,347	6,371,523
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	0	0
Unsecured senior notes payable	1,747,370	1,048,230
Unsecured senior line of credit	304,000	204,000
Unsecured senior bank term loans	975,000	1,100,000
Accounts payable, accrued expenses, and tenant security deposits	69,013	48,373
Dividends payable	58,525	54,131
Total liabilities	3,153,908	2,454,734
Redeemable noncontrolling interests	0	0
Alexandria's stockholders' equity	3,828,439	3,916,789
Noncontrolling interests	0	0
Total equity	3,828,439	3,916,789
Total liabilities, noncontrolling interests, and equity	6,982,347	6,371,523
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Assets
Investments in real estate	0	0
Cash and cash equivalents	63	0	1,914	0
Restricted cash	0	0
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing and financing costs	0	0
Investments	5,235	10,868
Investments in and advances to affiliates	6,295,852	5,823,058
Other assets	0	0
Total assets	6,301,150	5,833,926
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	0	0
Unsecured senior notes payable	0	0
Unsecured senior line of credit	0	0
Unsecured senior bank term loans	0	0
Accounts payable, accrued expenses, and tenant security deposits	0	0
Dividends payable	0	0
Total liabilities	0	0
Redeemable noncontrolling interests	0	0
Alexandria's stockholders' equity	6,301,150	5,833,926
Noncontrolling interests	0	0
Total equity	6,301,150	5,833,926
Total liabilities, noncontrolling interests, and equity	6,301,150	5,833,926
Combined Non- Guarantor Subsidiaries
Assets
Investments in real estate	7,226,016	6,776,914
Cash and cash equivalents	33,457	42,906	40,490	67,931
Restricted cash	26,817	27,654
Tenant receivables	10,548	9,918
Deferred rent	234,124	190,425
Deferred leasing and financing costs	166,336	155,757
Investments	231,154	129,420
Investments in and advances to affiliates	128,943	119,421
Other assets	94,805	113,930
Total assets	8,152,200	7,566,345
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	652,209	708,831
Unsecured senior notes payable	0	0
Unsecured senior line of credit	0	0
Unsecured senior bank term loans	0	0
Accounts payable, accrued expenses, and tenant security deposits	420,072	386,969
Dividends payable	289	289
Total liabilities	1,072,570	1,096,089
Redeemable noncontrolling interests	14,315	14,444
Alexandria's stockholders' equity	6,998,511	6,408,104
Noncontrolling interests	66,804	47,708
Total equity	7,065,315	6,455,812
Total liabilities, noncontrolling interests, and equity	8,152,200	7,566,345
Eliminations
Assets
Investments in real estate	0	0
Cash and cash equivalents	0	0	0	0
Restricted cash	0	0
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing and financing costs	0	0
Investments	0	0
Investments in and advances to affiliates	-13,299,661	-12,242,030
Other assets	0	0
Total assets	-13,299,661	-12,242,030
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	0	0
Unsecured senior notes payable	0	0
Unsecured senior line of credit	0	0
Unsecured senior bank term loans	0	0
Accounts payable, accrued expenses, and tenant security deposits	0	0
Dividends payable	0	0
Total liabilities	0	0
Redeemable noncontrolling interests	0	0
Alexandria's stockholders' equity	-13,299,661	-12,242,030
Noncontrolling interests	0	0
Total equity	-13,299,661	-12,242,030
Total liabilities, noncontrolling interests, and equity	($13,299,661)	($12,242,030)

Condensed_consolidating_financ3

Condensed consolidating financial information Income Statement (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues:
Rental									$544,153		$467,764		$422,793
Tenant recoveries									173,480		150,095		133,280
Other Income (expense)									9,244		13,292		18,424
Total revenues	188,674	185,615	176,402	176,186	168,823	158,315	153,930	150,083	726,877		631,151		574,497
Expenses:
Rental operations									219,164		189,039		172,756
General and administrative									53,530		48,520		47,747
Interest									79,299		67,952	[1]	69,184	[1]
Depreciation and amortization									224,096		189,123		185,687
Impairment of real estate									51,675		0		2,050
Loss on early extinguishment of debt									525		1,992		2,225
Total expenses									628,289		496,626		479,649
Equity in earnings of unconsolidated joint ventures									554		0		0
Equity in earnings of affiliates									0		0		0
Income from continuing operations									99,142		134,525		94,848
Income from discontinued operations									1,233	[2]	900	[2]	8,816	[2]
Gain on sales of real estate - land parcels									6,403		4,824		1,864
Net income									106,778		140,249		105,528
Dividends on preferred stock									-25,698		-25,885		-27,328
Preferred stock redemption charge									-1,989		0		-5,978
Net income attributable to noncontrolling interests									-5,204		-4,032		-3,402
Net income attributable to unvested restricted stock awards									-1,774		-1,581		-1,190
Net Income attributable to Alexandria's common stockholders	-16,154	27,626	27,932	32,709	36,247	24,579	25,483	22,442	72,113		108,751		67,630
Alexandria Real Estate Equities, Inc. (Issuer)
Revenues:
Rental									0		0		0
Tenant recoveries									0		0		0
Other Income (expense)									12,006		10,423		6,891
Total revenues									12,006		10,423		6,891
Expenses:
Rental operations									0		0		0
General and administrative									45,793		43,528		44,306
Interest									58,159		43,284		46,677
Depreciation and amortization									5,748		5,907		5,384
Impairment of real estate									0				0
Loss on early extinguishment of debt									525		1,992		2,225
Total expenses									110,225		94,711		98,592
Equity in earnings of unconsolidated joint ventures									0
Equity in earnings of affiliates									199,800		220,158		194,566
Income from continuing operations									101,581		135,870		102,865
Income from discontinued operations									-7		347		-739
Gain on sales of real estate - land parcels									0		0		0
Net income									101,574		136,217		102,126
Dividends on preferred stock									-25,698		-25,885		-27,328
Preferred stock redemption charge									-1,989				-5,978
Net income attributable to noncontrolling interests									0		0		0
Net income attributable to unvested restricted stock awards									-1,774		-1,581		-1,190
Net Income attributable to Alexandria's common stockholders									72,113		108,751		67,630
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Revenues:
Rental									0		0		0
Tenant recoveries									0		0		0
Other Income (expense)									-3,277		-74		1,292
Total revenues									-3,277		-74		1,292
Expenses:
Rental operations									0		0		0
General and administrative									0		0		3
Interest									0		0		0
Depreciation and amortization									0		0		0
Impairment of real estate									0				0
Loss on early extinguishment of debt									0		0		0
Total expenses									0		0		3
Equity in earnings of unconsolidated joint ventures									0
Equity in earnings of affiliates									188,269		205,993		183,139
Income from continuing operations									184,992		205,919		184,428
Income from discontinued operations									0		0		0
Gain on sales of real estate - land parcels									0		0		0
Net income									184,992		205,919		184,428
Dividends on preferred stock									0		0		0
Preferred stock redemption charge									0				0
Net income attributable to noncontrolling interests									0		0		0
Net income attributable to unvested restricted stock awards									0		0		0
Net Income attributable to Alexandria's common stockholders									184,992		205,919		184,428
Combined Non- Guarantor Subsidiaries
Revenues:
Rental									544,153		467,764		422,793
Tenant recoveries									173,480		150,095		133,280
Other Income (expense)									14,845		15,912		23,294
Total revenues									732,478		633,771		579,367
Expenses:
Rental operations									219,164		189,039		172,756
General and administrative									22,067		17,961		16,491
Interest									21,140		24,668		22,507
Depreciation and amortization									218,348		183,216		180,303
Impairment of real estate									51,675				2,050
Loss on early extinguishment of debt									0		0		0
Total expenses									532,394		414,884		394,107
Equity in earnings of unconsolidated joint ventures									554
Equity in earnings of affiliates									3,665		4,067		3,638
Income from continuing operations									204,303		222,954		188,898
Income from discontinued operations									1,240		553		9,555
Gain on sales of real estate - land parcels									6,403		4,824		1,864
Net income									211,946		228,331		200,317
Dividends on preferred stock									0		0		0
Preferred stock redemption charge									0				0
Net income attributable to noncontrolling interests									-5,204		-4,032		-3,402
Net income attributable to unvested restricted stock awards									0		0		0
Net Income attributable to Alexandria's common stockholders									206,742		224,299		196,915
Eliminations
Revenues:
Rental									0		0		0
Tenant recoveries									0		0		0
Other Income (expense)									-14,330		-12,969		-13,053
Total revenues									-14,330		-12,969		-13,053
Expenses:
Rental operations									0		0		0
General and administrative									-14,330		-12,969		-13,053
Interest									0		0		0
Depreciation and amortization									0		0		0
Impairment of real estate									0				0
Loss on early extinguishment of debt									0		0		0
Total expenses									-14,330		-12,969		-13,053
Equity in earnings of unconsolidated joint ventures									0
Equity in earnings of affiliates									-391,734		-430,218		-381,343
Income from continuing operations									-391,734		-430,218		-381,343
Income from discontinued operations									0		0		0
Gain on sales of real estate - land parcels									0		0		0
Net income									-391,734		-430,218		-381,343
Dividends on preferred stock									0		0		0
Preferred stock redemption charge									0				0
Net income attributable to noncontrolling interests									0		0		0
Net income attributable to unvested restricted stock awards									0		0		0
Net Income attributable to Alexandria's common stockholders									($391,734)		($430,218)		($381,343)
[1]	Includes interest expense related to and classified in income from discontinued operations in the accompanying consolidated statements of income.
[2]	Income from discontinued operations includes the results of operations of three properties that were disposed of during the year ended December 31, 2014, and the results of one property which was classified as “held for sale” prior to adoption of the new ASU and included as discontinued operations as of December 31, 2014, as well as the results of operations (prior to disposition) and gain (loss) on sale of real estate attributable to 16 properties sold during the period from January 1, 2012, to December 31, 2014.

Condensed_consolidating_financ4

Condensed consolidating financial information Comprehensive Income (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income	$106,778	$140,249	$105,528
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	51,135	1,300	990
Reclassification adjustment for losses (gains) included in net income	-358	-1,183	-3,351
Unrealized gains (losses) on marketable securities, net	50,777	117	-2,361
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	-4,459	1,918	-9,990
Reclassification adjustment for amortization of interest expense included in net income	6,871	15,422	22,309
Unrealized gains on interest rate swap agreements, net	2,412	17,340	12,319
Foreign Currency Translation [Abstract]
Unrealized foreign currency translation losses during the year	-18,075	-28,912	-318
Reclassification adjustment for gains included in net income	-208	0	0
Unrealized losses on foreign currency translation, net	-18,283	-28,912	-318
Total other comprehensive income (loss)	34,906	-11,455	9,640
Comprehensive income	141,684	128,794	115,168
Less: comprehensive income attributable to noncontrolling interests	-4,534	-3,948	-3,364
Comprehensive income attributable to Alexandria’s common stockholders	137,150	124,846	111,804
Alexandria Real Estate Equities, Inc. (Issuer)
Net income	101,574	136,217	102,126
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	0	0	0
Reclassification adjustment for losses (gains) included in net income	0	0	0
Unrealized gains (losses) on marketable securities, net	0	0	0
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	-4,459	1,918	-9,990
Reclassification adjustment for amortization of interest expense included in net income	6,871	15,422	22,309
Unrealized gains on interest rate swap agreements, net	2,412	17,340	12,319
Foreign Currency Translation [Abstract]
Unrealized foreign currency translation losses during the year	-318
Reclassification adjustment for gains included in net income	0
Unrealized losses on foreign currency translation, net	-318	0	0
Total other comprehensive income (loss)	2,094	17,340	12,319
Comprehensive income	103,668	153,557	114,445
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria’s common stockholders	103,668	153,557	114,445
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Net income	184,992	205,919	184,428
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	148	-438	-319
Reclassification adjustment for losses (gains) included in net income	292	148	155
Unrealized gains (losses) on marketable securities, net	440	-290	-164
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	0	0	0
Reclassification adjustment for amortization of interest expense included in net income	0	0	0
Unrealized gains on interest rate swap agreements, net	0	0	0
Foreign Currency Translation [Abstract]
Unrealized foreign currency translation losses during the year	0
Reclassification adjustment for gains included in net income	0
Unrealized losses on foreign currency translation, net	0	0	0
Total other comprehensive income (loss)	440	-290	-164
Comprehensive income	185,432	205,629	184,264
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria’s common stockholders	185,432	205,629	184,264
Combined Non- Guarantor Subsidiaries
Net income	211,946	228,331	200,317
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	50,987	1,738	1,309
Reclassification adjustment for losses (gains) included in net income	-650	-1,331	-3,506
Unrealized gains (losses) on marketable securities, net	50,337	407	-2,197
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	0	0	0
Reclassification adjustment for amortization of interest expense included in net income	0	0	0
Unrealized gains on interest rate swap agreements, net	0	0	0
Foreign Currency Translation [Abstract]
Unrealized foreign currency translation losses during the year	-17,757
Reclassification adjustment for gains included in net income	-208
Unrealized losses on foreign currency translation, net	-17,965	-28,912	-318
Total other comprehensive income (loss)	32,372	-28,505	-2,515
Comprehensive income	244,318	199,826	197,802
Less: comprehensive income attributable to noncontrolling interests	-4,534	-3,948	-3,364
Comprehensive income attributable to Alexandria’s common stockholders	239,784	195,878	194,438
Eliminations
Net income	-391,734	-430,218	-381,343
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	0	0	0
Reclassification adjustment for losses (gains) included in net income	0	0	0
Unrealized gains (losses) on marketable securities, net	0	0	0
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	0	0	0
Reclassification adjustment for amortization of interest expense included in net income	0	0	0
Unrealized gains on interest rate swap agreements, net	0	0	0
Foreign Currency Translation [Abstract]
Unrealized foreign currency translation losses during the year	0
Reclassification adjustment for gains included in net income	0
Unrealized losses on foreign currency translation, net	0	0	0
Total other comprehensive income (loss)	0	0	0
Comprehensive income	-391,734	-430,218	-381,343
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria’s common stockholders	($391,734)	($430,218)	($381,343)

Condensed_consolidating_financ5

Condensed consolidating financial information Cash Flows (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities
Net income	$106,778	$140,249	$105,528
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and Amortization	224,096	190,778	192,005
Loss on early extinguishment of debt	525	1,992	2,225
(Gain) loss on sale of real estate	-1,838	121	-1,564
Gain on sales of real estate - land parcels	-6,403	-4,824	-1,864
Impairment of real estate	51,675	0	13,450
Equity in earnings of unconsolidated joint ventures	-554	0	0
Distributions of earnings from unconsolidated joint ventures	549	0	0
Amortization of loan fees and costs	10,909	9,936	9,832
Amortization of debt premiums/discounts	117	529	511
Amortization of acquired above and below market leases	-2,845	-3,316	-3,200
Deferred rent	-44,726	-27,935	-28,456
Stock compensation expense	13,996	15,552	14,160
Equity in earnings of affiliates	0	0	0
Investment gains	-11,613	-7,050	-15,018
Investment losses	9,287	1,480	2,637
Changes in operating assets and liabilities:
Restricted cash	4,141	899	-261
Tenant receivables	-673	-1,519	-981
Deferred leasing costs	-38,282	-54,825	-45,099
Other assets	-7,466	-6,298	-4,069
Intercompany receivables and payables		0	0
Accounts payable, accrued expenses, and tenant security deposits	26,652	56,958	65,697
Net cash provided by operating activities	334,325	312,727	305,533
Investing Activities
Proceeds from sales of real estate	81,580	153,968	36,179
Additions to real estate	-497,773	-593,389	-549,030
Purchase of real estate	-127,887	-122,069	-42,171
Deposits for investing activities	-10,282	0	0
Change in restricted cash related to construction projects	1,665	7,655	-9,377
Investment in unconsolidated joint venture	-70,758	-17,987	-6,700
Distribution from unconsolidated joint venture	0	0	22,250
Payments to Acquire Interest in Subsidiaries and Affiliates	0	0	0
Additions to investments	-60,230	-36,078	-36,294
Proceeds from sales of investments	18,973	16,525	27,043
Financing Activities
Borrowings from secured notes payable	126,215	28,489	17,810
Repayments of borrowings from secured notes payable	-231,051	-36,219	-26,367
Principal borrowings from unsecured senior line of credit	1,168,000	729,000	847,147
Repayments of borrowings from unsecured senior line of credit	-1,068,000	-1,091,000	-651,147
Proceeds from issuance of unsecured senior notes payable	698,908	498,561	544,650
Repayment of unsecured senior bank term loan	-125,000	-250,000	-250,000
Redemption of Series D Cumulative Convertible Preferred Stock	-14,414	0	0
Repurchase of unsecured senior convertible notes	0	-384	-84,801
Redemption of Series C Cumulative Redeemable Preferred Stock	0	0	-129,638
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock	0	0	124,868
Transfers Due to (due from) Parent Entity	0	0	0
Change in restricted cash related to financings	-1,409	2,546	-7,428
Loan fees and costs paid	-8,099	-19,928	-13,225
Proceeds from common stock offerings	0	534,469	97,890
Proceeds from exercise of stock options	0	0	155
Dividends paid on common stock	-202,386	-169,076	-126,498
Dividends paid on preferred stock	-25,885	-25,885	-27,819
Distributions to redeemable noncontrolling interests	-1,191	-1,191	-1,249
Redemption of redeemable noncontrolling interests	0	0	-450
Contributions by noncontrolling interests	19,410	0	1,875
Distributions to noncontrolling interests	-3,786	-1,812	-913
Net cash provided by financing activities	331,312	197,570	314,860
Effect of foreign exchange rate changes on cash and cash equivalents	-2,493	-2,197	139
Net (decrease) increase in cash and cash equivalents	28,315	-83,275	62,432
Cash and cash equivalents at beginning of period	57,696	140,971	78,539
Cash and cash equivalents at end of period	86,011	57,696	140,971
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	57,966	59,857	52,561
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	2,000	38,820	6,125
Write-off of fully amortized improvements	0	0	-17,730
Change in accrued capital expenditures	-29,846	21,310	-46,087
Proceeds from repayment of notes receivable	29,883	0	0
Assumption of secured notes payable in connection with purchase of properties	-48,329	0	0
Net Cash Provided by (Used in) Investing Activities	-634,829	-591,375	-558,100
Alexandria Real Estate Equities, Inc. (Issuer)
Operating Activities
Net income	101,574	136,217	102,126
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and Amortization	5,748	5,907	6,490
Loss on early extinguishment of debt	525	1,992	2,225
(Gain) loss on sale of real estate	0	0	0
Gain on sales of real estate - land parcels	0	0	0
Impairment of real estate	0		6,400
Equity in earnings of unconsolidated joint ventures	0
Distributions of earnings from unconsolidated joint ventures	0
Amortization of loan fees and costs	7,355	6,914	9,204
Amortization of debt premiums/discounts	232	111	114
Amortization of acquired above and below market leases	0	0	0
Deferred rent	0	-82	-224
Stock compensation expense	13,996	15,552	14,160
Equity in earnings of affiliates	-199,800	-220,158	-194,566
Investment gains	0	0	0
Investment losses	0	0	0
Changes in operating assets and liabilities:
Restricted cash	-12	-2	-12
Tenant receivables	0	0	11
Deferred leasing costs	17	-37	-305
Other assets	-7,785	-5,606	1,329
Intercompany receivables and payables		3,021	-826
Accounts payable, accrued expenses, and tenant security deposits	25,877	-13,485	6,172
Net cash provided by operating activities	-52,273	-69,656	-47,702
Investing Activities
Proceeds from sales of real estate	0	10,796	0
Additions to real estate	-65	0	-1,313
Purchase of real estate	0	0	0
Deposits for investing activities	0
Change in restricted cash related to construction projects	0	0	0
Investment in unconsolidated joint venture	0	0	0
Distribution from unconsolidated joint venture			0
Payments to Acquire Interest in Subsidiaries and Affiliates	-334,764	-236,218	-197,665
Additions to investments	0	0	0
Proceeds from sales of investments	0	0	0
Financing Activities
Borrowings from secured notes payable	0	0	0
Repayments of borrowings from secured notes payable	0	0	0
Principal borrowings from unsecured senior line of credit	1,168,000	729,000	847,147
Repayments of borrowings from unsecured senior line of credit	-1,068,000	-1,091,000	-651,147
Proceeds from issuance of unsecured senior notes payable	698,908	498,561	544,650
Repayment of unsecured senior bank term loan	-125,000	-250,000	-250,000
Redemption of Series D Cumulative Convertible Preferred Stock	-14,414
Repurchase of unsecured senior convertible notes		-384	-84,801
Redemption of Series C Cumulative Redeemable Preferred Stock			-129,638
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock			124,868
Transfers Due to (due from) Parent Entity	103	0	0
Change in restricted cash related to financings	0	-1	0
Loan fees and costs paid	-6,523	-14,383	-10,180
Proceeds from common stock offerings		534,469	97,890
Proceeds from exercise of stock options			155
Dividends paid on common stock	-202,386	-169,076	-126,498
Dividends paid on preferred stock	-25,885	-25,885	-27,819
Distributions to redeemable noncontrolling interests	0	0	0
Redemption of redeemable noncontrolling interests			12
Contributions by noncontrolling interests	0		0
Distributions to noncontrolling interests	0	0	0
Net cash provided by financing activities	424,803	211,301	334,639
Effect of foreign exchange rate changes on cash and cash equivalents	0	0	0
Net (decrease) increase in cash and cash equivalents	37,701	-83,777	87,959
Cash and cash equivalents at beginning of period	14,790	98,567	10,608
Cash and cash equivalents at end of period	52,491	14,790	98,567
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	39,871	37,073	39,298
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	0	29,820	0
Write-off of fully amortized improvements			0
Change in accrued capital expenditures	0	0	2,000
Proceeds from repayment of notes receivable	0
Assumption of secured notes payable in connection with purchase of properties	0
Net Cash Provided by (Used in) Investing Activities	-334,829	-225,422	-198,978
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Operating Activities
Net income	184,992	205,919	184,428
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and Amortization	0	0	0
Loss on early extinguishment of debt	0	0	0
(Gain) loss on sale of real estate	0	0	0
Gain on sales of real estate - land parcels	0	0	0
Impairment of real estate	0		0
Equity in earnings of unconsolidated joint ventures	0
Distributions of earnings from unconsolidated joint ventures	0
Amortization of loan fees and costs	0	0	0
Amortization of debt premiums/discounts	0	0	0
Amortization of acquired above and below market leases	0	0	0
Deferred rent	0	0	0
Stock compensation expense	0	0	0
Equity in earnings of affiliates	-188,269	-205,993	-183,139
Investment gains	0	-3	-1,510
Investment losses	3,047	78	221
Changes in operating assets and liabilities:
Restricted cash	0	0	0
Tenant receivables	0	0	0
Deferred leasing costs	0	0	0
Other assets	0	0	0
Intercompany receivables and payables		0	0
Accounts payable, accrued expenses, and tenant security deposits	0	0	0
Net cash provided by operating activities	-230	1	0
Investing Activities
Proceeds from sales of real estate	0	0	0
Additions to real estate	0	0	0
Purchase of real estate	0	0	0
Deposits for investing activities	0
Change in restricted cash related to construction projects	0	0	0
Investment in unconsolidated joint venture	0	0	0
Distribution from unconsolidated joint venture			0
Payments to Acquire Interest in Subsidiaries and Affiliates	-251,358	-276,022	-158,022
Additions to investments	-150	0	-353
Proceeds from sales of investments	1,052	1,018	2,600
Financing Activities
Borrowings from secured notes payable	0	0	0
Repayments of borrowings from secured notes payable	0	0	0
Principal borrowings from unsecured senior line of credit	0	0	0
Repayments of borrowings from unsecured senior line of credit	0	0	0
Proceeds from issuance of unsecured senior notes payable	0	0	0
Repayment of unsecured senior bank term loan	0	0	0
Redemption of Series D Cumulative Convertible Preferred Stock	0
Repurchase of unsecured senior convertible notes		0	0
Redemption of Series C Cumulative Redeemable Preferred Stock			0
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock			0
Transfers Due to (due from) Parent Entity	250,749	273,089	157,689
Change in restricted cash related to financings	0	0	0
Loan fees and costs paid	0	0	0
Proceeds from common stock offerings		0	0
Proceeds from exercise of stock options			0
Dividends paid on common stock	0	0	0
Dividends paid on preferred stock	0	0	0
Distributions to redeemable noncontrolling interests	0	0	0
Redemption of redeemable noncontrolling interests			0
Contributions by noncontrolling interests	0		0
Distributions to noncontrolling interests	0	0	0
Net cash provided by financing activities	250,749	273,089	157,689
Effect of foreign exchange rate changes on cash and cash equivalents	0	0	0
Net (decrease) increase in cash and cash equivalents	63	-1,914	1,914
Cash and cash equivalents at beginning of period	0	1,914	0
Cash and cash equivalents at end of period	63	0	1,914
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	0	0	0
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	0	0	0
Write-off of fully amortized improvements			0
Change in accrued capital expenditures	0	0	0
Proceeds from repayment of notes receivable	0
Assumption of secured notes payable in connection with purchase of properties	0
Net Cash Provided by (Used in) Investing Activities	-250,456	-275,004	-155,775
Combined Non- Guarantor Subsidiaries
Operating Activities
Net income	211,946	228,331	200,317
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and Amortization	218,348	184,871	185,515
Loss on early extinguishment of debt	0	0	0
(Gain) loss on sale of real estate	-1,838	121	-1,564
Gain on sales of real estate - land parcels	-6,403	-4,824	-1,864
Impairment of real estate	51,675		7,050
Equity in earnings of unconsolidated joint ventures	-554
Distributions of earnings from unconsolidated joint ventures	549
Amortization of loan fees and costs	3,554	3,022	628
Amortization of debt premiums/discounts	-115	418	397
Amortization of acquired above and below market leases	-2,845	-3,316	-3,200
Deferred rent	-44,726	-27,853	-28,232
Stock compensation expense	0	0	0
Equity in earnings of affiliates	-3,665	-4,067	-3,638
Investment gains	-11,613	-7,047	-13,508
Investment losses	6,240	1,402	2,416
Changes in operating assets and liabilities:
Restricted cash	4,153	901	-249
Tenant receivables	-673	-1,519	-992
Deferred leasing costs	-38,299	-54,788	-44,794
Other assets	319	-692	-5,398
Intercompany receivables and payables		-3,021	826
Accounts payable, accrued expenses, and tenant security deposits	775	70,443	59,525
Net cash provided by operating activities	386,828	382,382	353,235
Investing Activities
Proceeds from sales of real estate	81,580	143,172	36,179
Additions to real estate	-497,708	-593,389	-547,717
Purchase of real estate	-127,887	-122,069	-42,171
Deposits for investing activities	-10,282
Change in restricted cash related to construction projects	1,665	7,655	-9,377
Investment in unconsolidated joint venture	-70,758	-17,987	-6,700
Distribution from unconsolidated joint venture			22,250
Payments to Acquire Interest in Subsidiaries and Affiliates	-13,441	-13,445	-1,179
Additions to investments	-60,080	-36,078	-35,941
Proceeds from sales of investments	17,921	15,507	24,443
Financing Activities
Borrowings from secured notes payable	126,215	28,489	17,810
Repayments of borrowings from secured notes payable	-231,051	-36,219	-26,367
Principal borrowings from unsecured senior line of credit	0	0	0
Repayments of borrowings from unsecured senior line of credit	0	0	0
Proceeds from issuance of unsecured senior notes payable	0	0	0
Repayment of unsecured senior bank term loan	0	0	0
Redemption of Series D Cumulative Convertible Preferred Stock	0
Repurchase of unsecured senior convertible notes		0	0
Redemption of Series C Cumulative Redeemable Preferred Stock			0
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock			0
Transfers Due to (due from) Parent Entity	348,711	252,596	199,177
Change in restricted cash related to financings	-1,409	2,547	-7,428
Loan fees and costs paid	-1,576	-5,545	-3,045
Proceeds from common stock offerings		0	0
Proceeds from exercise of stock options			0
Dividends paid on common stock	0	0	0
Dividends paid on preferred stock	0	0	0
Distributions to redeemable noncontrolling interests	-1,191	-1,191	-1,249
Redemption of redeemable noncontrolling interests			-462
Contributions by noncontrolling interests	19,410		1,875
Distributions to noncontrolling interests	-3,786	-1,812	-913
Net cash provided by financing activities	255,323	238,865	179,398
Effect of foreign exchange rate changes on cash and cash equivalents	-2,493	-2,197	139
Net (decrease) increase in cash and cash equivalents	-9,449	2,416	-27,441
Cash and cash equivalents at beginning of period	42,906	40,490	67,931
Cash and cash equivalents at end of period	33,457	42,906	40,490
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	18,095	22,784	13,263
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	2,000	9,000	6,125
Write-off of fully amortized improvements			-17,730
Change in accrued capital expenditures	29,846	-21,310	-48,087
Proceeds from repayment of notes receivable	29,883
Assumption of secured notes payable in connection with purchase of properties	-48,329
Net Cash Provided by (Used in) Investing Activities	-649,107	-616,634	-560,213
Eliminations
Operating Activities
Net income	-391,734	-430,218	-381,343
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and Amortization	0	0	0
Loss on early extinguishment of debt	0	0	0
(Gain) loss on sale of real estate	0	0	0
Gain on sales of real estate - land parcels	0	0	0
Impairment of real estate	0		0
Equity in earnings of unconsolidated joint ventures	0
Distributions of earnings from unconsolidated joint ventures	0
Amortization of loan fees and costs	0	0	0
Amortization of debt premiums/discounts	0	0	0
Amortization of acquired above and below market leases	0	0	0
Deferred rent	0	0	0
Stock compensation expense	0	0	0
Equity in earnings of affiliates	391,734	430,218	381,343
Investment gains	0	0	0
Investment losses	0	0	0
Changes in operating assets and liabilities:
Restricted cash	0	0	0
Tenant receivables	0	0	0
Deferred leasing costs	0	0	0
Other assets	0	0	0
Intercompany receivables and payables		0	0
Accounts payable, accrued expenses, and tenant security deposits	0	0	0
Net cash provided by operating activities	0	0	0
Investing Activities
Proceeds from sales of real estate	0	0	0
Additions to real estate	0	0	0
Purchase of real estate	0	0	0
Deposits for investing activities	0
Change in restricted cash related to construction projects	0	0	0
Investment in unconsolidated joint venture	0	0	0
Distribution from unconsolidated joint venture			0
Payments to Acquire Interest in Subsidiaries and Affiliates	599,563	525,685	356,866
Additions to investments	0	0	0
Proceeds from sales of investments	0	0	0
Financing Activities
Borrowings from secured notes payable	0	0	0
Repayments of borrowings from secured notes payable	0	0	0
Principal borrowings from unsecured senior line of credit	0	0	0
Repayments of borrowings from unsecured senior line of credit	0	0	0
Proceeds from issuance of unsecured senior notes payable	0	0	0
Repayment of unsecured senior bank term loan	0	0	0
Redemption of Series D Cumulative Convertible Preferred Stock	0
Repurchase of unsecured senior convertible notes		0	0
Redemption of Series C Cumulative Redeemable Preferred Stock			0
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock			0
Transfers Due to (due from) Parent Entity	-599,563	-525,685	-356,866
Change in restricted cash related to financings	0	0	0
Loan fees and costs paid	0	0	0
Proceeds from common stock offerings		0	0
Proceeds from exercise of stock options			0
Dividends paid on common stock	0	0	0
Dividends paid on preferred stock	0	0	0
Distributions to redeemable noncontrolling interests	0	0	0
Redemption of redeemable noncontrolling interests			0
Contributions by noncontrolling interests	0		0
Distributions to noncontrolling interests	0	0	0
Net cash provided by financing activities	-599,563	-525,685	-356,866
Effect of foreign exchange rate changes on cash and cash equivalents	0	0	0
Net (decrease) increase in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	0	0	0
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	0	0	0
Non-Cash Investing Activities
Note receivable issued in connection with sale of real estate	0	0	0
Write-off of fully amortized improvements			0
Change in accrued capital expenditures	0	0	0
Proceeds from repayment of notes receivable	0
Assumption of secured notes payable in connection with purchase of properties	0
Net Cash Provided by (Used in) Investing Activities	$599,563	$525,685	$356,866

Schedule_III_Consolidated_Fina1

Schedule III - Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	652,209
Initial Costs
Land	1,057,802
Buildings & Improvements	2,791,443
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	4,497,016
Total Costs
Land	1,057,802
Buildings & Improvements	7,288,459
Total	8,346,261	[1]
Accumulated Depreciation	-1,120,245	[2]	-952,106	-875,035	-742,535
Net Cost Basis	7,226,016
Secured notes payable	652,209		708,831
Area of Real Estate Property	18,729,282
Alexandria Center at Kendall Square
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	106,093
Initial Costs
Land	280,713
Buildings & Improvements	199,583
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	662,031
Total Costs
Land	280,713
Buildings & Improvements	861,614
Total	1,142,327	[1]
Accumulated Depreciation	-44,490	[2]
Net Cost Basis	1,097,837
Alexandria Technology Square®
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	619,658
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	186,472
Total Costs
Land	0
Buildings & Improvements	806,130
Total	806,130	[1]
Accumulated Depreciation	-141,360	[2]
Net Cost Basis	664,770
480 Arsenal Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	6,413
Buildings & Improvements	5,457
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	46,115
Total Costs
Land	6,413
Buildings & Improvements	51,572
Total	57,985	[1]
Accumulated Depreciation	-14,358	[2]
Net Cost Basis	43,627
780/790 Memorial Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	45,140
Total Costs
Land	0
Buildings & Improvements	45,140
Total	45,140	[1]
Accumulated Depreciation	-17,895	[2]
Net Cost Basis	27,245
500 Arsenal Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	3,360
Buildings & Improvements	7,316
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	29,136
Total Costs
Land	3,360
Buildings & Improvements	36,452
Total	39,812	[1]
Accumulated Depreciation	-13,368	[2]
Net Cost Basis	26,444
167 Sidney Street/99 Erie Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	12,613
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	12,273
Total Costs
Land	0
Buildings & Improvements	24,886
Total	24,886	[1]
Accumulated Depreciation	-4,064	[2]
Net Cost Basis	20,822
79/96 Thirteenth Street Charlestown Navy Yard
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	4,556	[3]
Initial Costs
Land	0
Buildings & Improvements	6,247
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	8,661
Total Costs
Land	0
Buildings & Improvements	14,908
Total	14,908	[1]
Accumulated Depreciation	-2,785	[2]
Net Cost Basis	12,123
Alexandria Park at 128
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	23,301	[3],[4]
Initial Costs
Land	10,439
Buildings & Improvements	41,596
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	56,059
Total Costs
Land	10,439
Buildings & Improvements	97,655
Total	108,094	[1]
Accumulated Depreciation	-27,003	[2]
Net Cost Basis	81,091
225 Second Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,925
Buildings & Improvements	14,913
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	17,047
Total Costs
Land	2,925
Buildings & Improvements	31,960
Total	34,885	[1]
Accumulated Depreciation	0	[2]
Net Cost Basis	34,885
19 Presidential Way
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	12,833
Buildings & Improvements	27,333
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	66
Total Costs
Land	12,833
Buildings & Improvements	27,399
Total	40,232	[1]
Accumulated Depreciation	-6,621	[2]
Net Cost Basis	33,611
100 Beaver Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,466
Buildings & Improvements	9,046
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	11,742
Total Costs
Land	1,466
Buildings & Improvements	20,788
Total	22,254	[1]
Accumulated Depreciation	-4,169	[2]
Net Cost Basis	18,085
285 Bear Hill Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	422
Buildings & Improvements	3,538
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	5,189
Total Costs
Land	422
Buildings & Improvements	8,727
Total	9,149	[1]
Accumulated Depreciation	-340	[2]
Net Cost Basis	8,809
111/130 Forbes Boulevard
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	3,146
Buildings & Improvements	15,725
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	2,936
Total Costs
Land	3,146
Buildings & Improvements	18,661
Total	21,807	[1]
Accumulated Depreciation	-3,940	[2]
Net Cost Basis	17,867
20 Walkup Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,261
Buildings & Improvements	7,099
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	9,029
Total Costs
Land	2,261
Buildings & Improvements	16,128
Total	18,389	[1]
Accumulated Depreciation	-1,639	[2]
Net Cost Basis	16,750
306 Belmont Street & 350 Plantation Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,806
Buildings & Improvements	11,696
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	1,783
Total Costs
Land	1,806
Buildings & Improvements	13,479
Total	15,285	[1]
Accumulated Depreciation	-3,594	[2]
Net Cost Basis	11,691
30 Bearfoot Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,220
Buildings & Improvements	22,375
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	44
Total Costs
Land	1,220
Buildings & Improvements	22,419
Total	23,639	[1]
Accumulated Depreciation	-5,512	[2]
Net Cost Basis	18,127
Alexandria Center for Science and Technology
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	93,813
Buildings & Improvements	210,211
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	370,840
Total Costs
Land	93,813
Buildings & Improvements	581,051
Total	674,864	[1]
Accumulated Depreciation	-53,840	[2]
Net Cost Basis	621,024
Alexandria Technology Center - Gateway
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	98,133	[5]
Initial Costs
Land	45,425
Buildings & Improvements	121,059
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	15,378
Total Costs
Land	45,425
Buildings & Improvements	136,437
Total	181,862	[1]
Accumulated Depreciation	-35,125	[2]
Net Cost Basis	146,737
249/259/269 East Grande Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	66,135
Initial Costs
Land	19,396
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	151,275
Total Costs
Land	19,396
Buildings & Improvements	151,275
Total	170,671	[1]
Accumulated Depreciation	-14,070	[2]
Net Cost Basis	156,601
400 & 450 East Jamie Court
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	109,622
Total Costs
Land	0
Buildings & Improvements	109,622
Total	109,622	[1]
Accumulated Depreciation	-15,612	[2]
Net Cost Basis	94,010
500 Forbes Boulevard
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	35,596
Buildings & Improvements	69,091
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	14,441
Total Costs
Land	35,596
Buildings & Improvements	83,532
Total	119,128	[1]
Accumulated Depreciation	-16,450	[2]
Net Cost Basis	102,678
7000 Shoreline Court
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	31,234	[5]
Initial Costs
Land	7,038
Buildings & Improvements	39,704
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	9,070
Total Costs
Land	7,038
Buildings & Improvements	48,774
Total	55,812	[1]
Accumulated Depreciation	-11,684	[2]
Net Cost Basis	44,128
341 & 343 Oyster Point Boulevard
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	7,038
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	31,968
Total Costs
Land	7,038
Buildings & Improvements	31,968
Total	39,006	[1]
Accumulated Depreciation	-13,517	[2]
Net Cost Basis	25,489
839 - 863 Mitten and 866 Malcolm
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	3,211
Buildings & Improvements	8,665
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	15,307
Total Costs
Land	3,211
Buildings & Improvements	23,972
Total	27,183	[1]
Accumulated Depreciation	-8,139	[2]
Net Cost Basis	19,044
2425 Garcia Avenue & 2450 Bayshore Parkway
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	830
Initial Costs
Land	1,512
Buildings & Improvements	21,323
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	25,150
Total Costs
Land	1,512
Buildings & Improvements	46,473
Total	47,985	[1]
Accumulated Depreciation	-16,339	[2]
Net Cost Basis	31,646
3165 Porter Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	20,421	[4]
Initial Costs
Land	0
Buildings & Improvements	19,154
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	2,105
Total Costs
Land	0
Buildings & Improvements	21,259
Total	21,259	[1]
Accumulated Depreciation	-5,686	[2]
Net Cost Basis	15,573
75/125 Shoreway Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	6,617
Buildings & Improvements	7,091
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	10,852
Total Costs
Land	6,617
Buildings & Improvements	17,943
Total	24,560	[1]
Accumulated Depreciation	-3,069	[2]
Net Cost Basis	21,491
3350 West Bayshore Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	4,800
Buildings & Improvements	6,693
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	10,940
Total Costs
Land	4,800
Buildings & Improvements	17,633
Total	22,433	[1]
Accumulated Depreciation	-3,486	[2]
Net Cost Basis	18,947
2625 & 2631 Hanover Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	6,628
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	10,488
Total Costs
Land	0
Buildings & Improvements	17,116
Total	17,116	[1]
Accumulated Depreciation	-7,440	[2]
Net Cost Basis	9,676
Alexandria Center for Life Science
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	778,293
Total Costs
Land	0
Buildings & Improvements	778,293
Total	778,293	[1]
Accumulated Depreciation	-47,615	[2]
Net Cost Basis	730,678
100 Phillips Parkway
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	9,353	[3]
Initial Costs
Land	1,840
Buildings & Improvements	2,298
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	14,897
Total Costs
Land	1,840
Buildings & Improvements	17,195
Total	19,035	[1]
Accumulated Depreciation	-7,917	[2]
Net Cost Basis	11,118
102 Witmer Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,625
Buildings & Improvements	19,715
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	5,641
Total Costs
Land	1,625
Buildings & Improvements	25,356
Total	26,981	[1]
Accumulated Depreciation	-6,279	[2]
Net Cost Basis	20,702
701 Veterans Circle
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,468
Buildings & Improvements	7,885
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	26
Total Costs
Land	1,468
Buildings & Improvements	7,911
Total	9,379	[1]
Accumulated Depreciation	-1,485	[2]
Net Cost Basis	7,894
5100 Campus Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	256
Buildings & Improvements	2,117
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	469
Total Costs
Land	256
Buildings & Improvements	2,586
Total	2,842	[1]
Accumulated Depreciation	-1,254	[2]
Net Cost Basis	1,588
ARE Nautilus
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	6,684
Buildings & Improvements	27,600
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	83,309
Total Costs
Land	6,684
Buildings & Improvements	110,909
Total	117,593	[1]
Accumulated Depreciation	-24,872	[2]
Net Cost Basis	92,721
ARE Sunrise
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	19,590	[6]
Initial Costs
Land	2,954
Buildings & Improvements	15,491
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	41,518
Total Costs
Land	2,954
Buildings & Improvements	57,009
Total	59,963	[1]
Accumulated Depreciation	-29,960	[2]
Net Cost Basis	30,003
ARE Spectrum
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	27,388
Buildings & Improvements	80,957
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	46,944
Total Costs
Land	27,388
Buildings & Improvements	127,901
Total	155,289	[1]
Accumulated Depreciation	-15,905	[2]
Net Cost Basis	139,384
11119 North Torrey Pines Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	9,994
Buildings & Improvements	37,099
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	32,505
Total Costs
Land	9,994
Buildings & Improvements	69,604
Total	79,598	[1]
Accumulated Depreciation	-6,188	[2]
Net Cost Basis	73,410
3545 Cray Court
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	39,387
Initial Costs
Land	7,056
Buildings & Improvements	53,944
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	0
Total Costs
Land	7,056
Buildings & Improvements	53,944
Total	61,000	[1]
Accumulated Depreciation	-4,864	[2]
Net Cost Basis	56,136
5200 Illumina Way
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	38,340
Buildings & Improvements	96,606
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	73,541
Total Costs
Land	38,340
Buildings & Improvements	170,147
Total	208,487	[1]
Accumulated Depreciation	-15,176	[2]
Net Cost Basis	193,311
9363 Towne Centre Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	8,539
Buildings & Improvements	18,850
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	3,695
Total Costs
Land	8,539
Buildings & Improvements	22,545
Total	31,084	[1]
Accumulated Depreciation	-3,431	[2]
Net Cost Basis	27,653
10300 Campus Point Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	22,487
Buildings & Improvements	90,198
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	102,464
Total Costs
Land	22,487
Buildings & Improvements	192,662
Total	215,149	[1]
Accumulated Depreciation	-12,655	[2]
Net Cost Basis	202,494
ARE Esplanade
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	11,452	[6]
Initial Costs
Land	9,682
Buildings & Improvements	29,991
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	45,439
Total Costs
Land	9,682
Buildings & Improvements	75,430
Total	85,112	[1]
Accumulated Depreciation	-9,459	[2]
Net Cost Basis	75,653
ARE Towne Centre
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	34,110	[4]
Initial Costs
Land	8,539
Buildings & Improvements	18,850
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	40,293
Total Costs
Land	8,539
Buildings & Improvements	59,143
Total	67,682	[1]
Accumulated Depreciation	-31,899	[2]
Net Cost Basis	35,783
9880 Campus Point Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	3,823
Buildings & Improvements	16,165
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	20,053
Total Costs
Land	3,823
Buildings & Improvements	36,218
Total	40,041	[1]
Accumulated Depreciation	-8,915	[2]
Net Cost Basis	31,126
5810 & 5820 & 6138 & 6150 Nancy Ridge Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	11,435	[4]
Initial Costs
Land	5,476
Buildings & Improvements	28,682
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	1,811
Total Costs
Land	5,476
Buildings & Improvements	30,493
Total	35,969	[1]
Accumulated Depreciation	-7,743	[2]
Net Cost Basis	28,226
ARE Portola
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	6,991
Buildings & Improvements	25,153
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	17,734
Total Costs
Land	6,991
Buildings & Improvements	42,887
Total	49,878	[1]
Accumulated Depreciation	-4,905	[2]
Net Cost Basis	44,973
10121 & 10151 Barnes Canyon Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	4,608
Buildings & Improvements	5,100
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	14,257
Total Costs
Land	4,608
Buildings & Improvements	19,357
Total	23,965	[1]
Accumulated Depreciation	-188	[2]
Net Cost Basis	23,777
7330 Carroll Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	4,517	[3]
Initial Costs
Land	2,650
Buildings & Improvements	19,878
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	1,253
Total Costs
Land	2,650
Buildings & Improvements	21,131
Total	23,781	[1]
Accumulated Depreciation	-2,347	[2]
Net Cost Basis	21,434
5871 Oberlin Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,349
Buildings & Improvements	8,016
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	3,623
Total Costs
Land	1,349
Buildings & Improvements	11,639
Total	12,988	[1]
Accumulated Depreciation	-949	[2]
Net Cost Basis	12,039
6146/6166 Nancy Ridge Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	515
Buildings & Improvements	1,566
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	2,844
Total Costs
Land	515
Buildings & Improvements	4,410
Total	4,925	[1]
Accumulated Depreciation	-2,183	[2]
Net Cost Basis	2,742
11025 & 11045 Roselle Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	4,156
Buildings & Improvements	11,571
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	22,161
Total Costs
Land	4,156
Buildings & Improvements	33,732
Total	37,888	[1]
Accumulated Depreciation	-5,828	[2]
Net Cost Basis	32,060
3985 Sorrento Valley Boulevard
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	7,333	[7]
Initial Costs
Land	4,323
Buildings & Improvements	22,846
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	3,568
Total Costs
Land	4,323
Buildings & Improvements	26,414
Total	30,737	[1]
Accumulated Depreciation	-2,651	[2]
Net Cost Basis	28,086
Unamortized Discount	242
13112 Evening Creek Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	12,398	[6]
Initial Costs
Land	7,393
Buildings & Improvements	27,950
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	150
Total Costs
Land	7,393
Buildings & Improvements	28,100
Total	35,493	[1]
Accumulated Depreciation	-5,504	[2]
Net Cost Basis	29,989
1201/1208 Eastlake Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	41,830	[6]
Initial Costs
Land	5,810
Buildings & Improvements	47,149
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	14,955
Total Costs
Land	5,810
Buildings & Improvements	62,104
Total	67,914	[1]
Accumulated Depreciation	-18,941	[2]
Net Cost Basis	48,973
1616 Eastlake Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	6,940
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	82,526
Total Costs
Land	6,940
Buildings & Improvements	82,526
Total	89,466	[1]
Accumulated Depreciation	-17,874	[2]
Net Cost Basis	71,592
1551 Eastlake Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	8,525
Buildings & Improvements	20,064
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	32,893
Total Costs
Land	8,525
Buildings & Improvements	52,957
Total	61,482	[1]
Accumulated Depreciation	-6,055	[2]
Net Cost Basis	55,427
199 East Blaine Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	6,528
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	71,707
Total Costs
Land	6,528
Buildings & Improvements	71,707
Total	78,235	[1]
Accumulated Depreciation	-9,980	[2]
Net Cost Basis	68,255
219 Terry Avenue North
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,819
Buildings & Improvements	2,302
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	18,943
Total Costs
Land	1,819
Buildings & Improvements	21,245
Total	23,064	[1]
Accumulated Depreciation	-1,705	[2]
Net Cost Basis	21,359
1600 Fairview Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,212
Buildings & Improvements	6,788
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	6,009
Total Costs
Land	2,212
Buildings & Improvements	12,797
Total	15,009	[1]
Accumulated Depreciation	-2,611	[2]
Net Cost Basis	12,398
3000/3018 Western Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,432
Buildings & Improvements	7,497
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	21,590
Total Costs
Land	1,432
Buildings & Improvements	29,087
Total	30,519	[1]
Accumulated Depreciation	-7,528	[2]
Net Cost Basis	22,991
410 West Harrison/410 Elliott Avenue West
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	3,857
Buildings & Improvements	1,989
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	10,549
Total Costs
Land	3,857
Buildings & Improvements	12,538
Total	16,395	[1]
Accumulated Depreciation	-2,604	[2]
Net Cost Basis	13,791
9980 Medical Center Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	76,000
Initial Costs
Land	10,052
Buildings & Improvements	99,696
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	96,305
Total Costs
Land	10,052
Buildings & Improvements	196,001
Total	206,053	[1]
Accumulated Depreciation	-40,359	[2]
Net Cost Basis	165,694
1330 Piccard Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,800
Buildings & Improvements	11,533
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	28,928
Total Costs
Land	2,800
Buildings & Improvements	40,461
Total	43,261	[1]
Accumulated Depreciation	-12,517	[2]
Net Cost Basis	30,744
1500/1550 East Gude Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,523
Buildings & Improvements	7,731
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	5,511
Total Costs
Land	1,523
Buildings & Improvements	13,242
Total	14,765	[1]
Accumulated Depreciation	-4,919	[2]
Net Cost Basis	9,846
14920/15010 Broschart Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	5,804	[8]
Initial Costs
Land	4,904
Buildings & Improvements	15,846
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	3,823
Total Costs
Land	4,904
Buildings & Improvements	19,669
Total	24,573	[1]
Accumulated Depreciation	-3,152	[2]
Net Cost Basis	21,421
Unamortized Discount	27
1405 Research Boulevard
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	899
Buildings & Improvements	21,946
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	11,515
Total Costs
Land	899
Buildings & Improvements	33,461
Total	34,360	[1]
Accumulated Depreciation	-10,165	[2]
Net Cost Basis	24,195
5 Research Court
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,466
Buildings & Improvements	5,708
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	27,007
Total Costs
Land	1,466
Buildings & Improvements	32,715
Total	34,181	[1]
Accumulated Depreciation	-6,427	[2]
Net Cost Basis	27,754
9920 Medical Center Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	5,791
Buildings & Improvements	8,060
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	1,071
Total Costs
Land	5,791
Buildings & Improvements	9,131
Total	14,922	[1]
Accumulated Depreciation	-2,141	[2]
Net Cost Basis	12,781
5 Research Court
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,647
Buildings & Improvements	13,258
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	5,199
Total Costs
Land	1,647
Buildings & Improvements	18,457
Total	20,104	[1]
Accumulated Depreciation	-13,489	[2]
Net Cost Basis	6,615
12301 Parklawn Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,476
Buildings & Improvements	7,267
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	561
Total Costs
Land	1,476
Buildings & Improvements	7,828
Total	9,304	[1]
Accumulated Depreciation	-1,912	[2]
Net Cost Basis	7,392
Alexandria Technology Center - Gaithersburg I
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	10,183
Buildings & Improvements	59,641
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	21,652
Total Costs
Land	10,183
Buildings & Improvements	81,293
Total	91,476	[1]
Accumulated Depreciation	-22,561	[2]
Net Cost Basis	68,915
Alexandria Technology Center - Gaithersburg II
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	4,531
Buildings & Improvements	21,594
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	31,651
Total Costs
Land	4,531
Buildings & Improvements	53,245
Total	57,776	[1]
Accumulated Depreciation	-21,028	[2]
Net Cost Basis	36,748
16020 Industrial Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,924
Buildings & Improvements	19,664
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	714
Total Costs
Land	2,924
Buildings & Improvements	20,378
Total	23,302	[1]
Accumulated Depreciation	-9,349	[2]
Net Cost Basis	13,953
401 Professional Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,129
Buildings & Improvements	6,941
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	5,745
Total Costs
Land	1,129
Buildings & Improvements	12,686
Total	13,815	[1]
Accumulated Depreciation	-4,603	[2]
Net Cost Basis	9,212
950 Wind River Lane
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,400
Buildings & Improvements	10,620
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	1,050
Total Costs
Land	2,400
Buildings & Improvements	11,670
Total	14,070	[1]
Accumulated Depreciation	-1,557	[2]
Net Cost Basis	12,513
620 Professional Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	784
Buildings & Improvements	4,705
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	7,216
Total Costs
Land	784
Buildings & Improvements	11,921
Total	12,705	[1]
Accumulated Depreciation	-1,320	[2]
Net Cost Basis	11,385
8000/9000/10000 Virginia Manor Road
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	13,679
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	5,847
Total Costs
Land	0
Buildings & Improvements	19,526
Total	19,526	[1]
Accumulated Depreciation	-7,765	[2]
Net Cost Basis	11,761
14225 Newbrook Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	28,297	[6]
Initial Costs
Land	4,800
Buildings & Improvements	27,639
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	6,863
Total Costs
Land	4,800
Buildings & Improvements	34,502
Total	39,302	[1]
Accumulated Depreciation	-12,542	[2]
Net Cost Basis	26,760
Alexandria Technology Center - Alston
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,430
Buildings & Improvements	17,482
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	27,781
Total Costs
Land	1,430
Buildings & Improvements	45,263
Total	46,693	[1]
Accumulated Depreciation	-17,701	[2]
Net Cost Basis	28,992
108/110/112/114 Alexander Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	376
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	42,050
Total Costs
Land	0
Buildings & Improvements	42,426
Total	42,426	[1]
Accumulated Depreciation	-11,837	[2]
Net Cost Basis	30,589
Alexandria Innovation Center - Research Triangle Park
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,065
Buildings & Improvements	21,218
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	24,461
Total Costs
Land	1,065
Buildings & Improvements	45,679
Total	46,744	[1]
Accumulated Depreciation	-11,144	[2]
Net Cost Basis	35,600
6 Davis Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	9,920
Buildings & Improvements	10,712
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	7,573
Total Costs
Land	9,920
Buildings & Improvements	18,285
Total	28,205	[1]
Accumulated Depreciation	-3,623	[2]
Net Cost Basis	24,582
7 Triangle Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	701
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	31,643
Total Costs
Land	701
Buildings & Improvements	31,643
Total	32,344	[1]
Accumulated Depreciation	-2,914	[2]
Net Cost Basis	29,430
407 Davis Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	1,229
Buildings & Improvements	17,733
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	0
Total Costs
Land	1,229
Buildings & Improvements	17,733
Total	18,962	[1]
Accumulated Depreciation	-683	[2]
Net Cost Basis	18,279
2525 East NC Highway 54
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	713
Buildings & Improvements	12,827
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	894
Total Costs
Land	713
Buildings & Improvements	13,721
Total	14,434	[1]
Accumulated Depreciation	-3,685	[2]
Net Cost Basis	10,749
601 Keystone Park Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	785
Buildings & Improvements	11,546
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	5,017
Total Costs
Land	785
Buildings & Improvements	16,563
Total	17,348	[1]
Accumulated Depreciation	-3,140	[2]
Net Cost Basis	14,208
5 Triangle Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	161
Buildings & Improvements	3,409
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	2,857
Total Costs
Land	161
Buildings & Improvements	6,266
Total	6,427	[1]
Accumulated Depreciation	-2,074	[2]
Net Cost Basis	4,353
6101 Quadrangle Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	951
Buildings & Improvements	3,982
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	9,462
Total Costs
Land	951
Buildings & Improvements	13,444
Total	14,395	[1]
Accumulated Depreciation	-1,221	[2]
Net Cost Basis	13,174
555 Heritage Drive
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,919
Buildings & Improvements	5,311
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	11,959
Total Costs
Land	2,919
Buildings & Improvements	17,270
Total	20,189	[1]
Accumulated Depreciation	-2,461	[2]
Net Cost Basis	17,728
661 University Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0	[9]
Initial Costs
Land	0	[9]
Buildings & Improvements	0	[9]
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	63,511	[9]
Total Costs
Land	0	[9]
Buildings & Improvements	63,511	[9]
Total	63,511	[1],[9]
Accumulated Depreciation	-12,016	[2],[9]
Net Cost Basis	51,495	[9]
1781 W. 75th Avenue
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,059
Buildings & Improvements	4,244
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	8,482
Total Costs
Land	2,059
Buildings & Improvements	12,726
Total	14,785	[1]
Accumulated Depreciation	-2,235	[2]
Net Cost Basis	12,550
7990 Enterprise Street
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,277
Buildings & Improvements	8,864
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	0
Total Costs
Land	2,277
Buildings & Improvements	8,864
Total	11,141	[1]
Accumulated Depreciation	-1,979	[2]
Net Cost Basis	9,162
275 Armand Frappier
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	6,986
Buildings & Improvements	23,043
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	6,477
Total Costs
Land	6,986
Buildings & Improvements	29,520
Total	36,506	[1]
Accumulated Depreciation	-5,529	[2]
Net Cost Basis	30,977
525 Cartier Boulevard West
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	2,926
Buildings & Improvements	18,746
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	0
Total Costs
Land	2,926
Buildings & Improvements	18,746
Total	21,672	[1]
Accumulated Depreciation	-4,604	[2]
Net Cost Basis	17,068
510 Townsend Street [Member]
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	52,105
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	6,354
Total Costs
Land	52,105
Buildings & Improvements	6,354
Total	58,459	[1]
Accumulated Depreciation	0	[2]
Net Cost Basis	58,459
560 Eccles Avenue [Member]
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	12,093
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	5,562
Total Costs
Land	12,093
Buildings & Improvements	5,562
Total	17,655	[1]
Accumulated Depreciation	-3	[2]
Net Cost Basis	17,652
Grand Avenue [Member]
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	37,538
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	7,518
Total Costs
Land	37,538
Buildings & Improvements	7,518
Total	45,056	[1]
Accumulated Depreciation	-21	[2]
Net Cost Basis	45,035
China
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	0
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	85,845
Total Costs
Land	0
Buildings & Improvements	85,845
Total	85,845	[1]
Accumulated Depreciation	-3,625	[2]
Net Cost Basis	82,220
India
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	32,433
Buildings & Improvements	0
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	139,726
Total Costs
Land	32,433
Buildings & Improvements	139,726
Total	172,159	[1]
Accumulated Depreciation	-5,746	[2]
Net Cost Basis	166,413
Various
Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation
Encumbrances	0
Initial Costs
Land	64,032
Buildings & Improvements	27,141
Costs Capitalized Subsequent to Acquisition
Buildings & Improvements	266,062
Total Costs
Land	64,032
Buildings & Improvements	293,203
Total	357,235	[1]
Accumulated Depreciation	-28,564	[2]
Net Cost Basis	328,671
7330 Carroll Road, 100 Phillips Parkway, 79/96 Thirteen Street, Alexandria Park at 128 [Member]
Total Costs
Secured notes payable	30,377
Number of real estate properties subject to secured debt	4
Alexandria at 128, 3165 Porter Drive, ARE Towne Center, 5810/5820/6138/6150 Nancy Ridge Drive [Member]
Total Costs
Secured notes payable	77,316
Number of real estate properties subject to secured debt	6
Alexandria Technology Center - Gateway, 7000 Shoreline Court [Member]
Total Costs
Secured notes payable	129,367
Number of real estate properties subject to secured debt	4
14225 Newbrook Drive, 1201 and 1208 Eastlake Avenue, 13112 Evening Creek Drive, ARE Esplanade, ARE Sunrise [Member]
Total Costs
Secured notes payable	113,567
Number of real estate properties subject to secured debt	6
Land improvements
Total Costs
Estimated useful life	20 years
Minimum | Buildings and building improvements
Total Costs
Estimated useful life	30 years
Maximum | Buildings and building improvements
Total Costs
Estimated useful life	40 years
Asset under Construction | Number 661 University Avenue [Member]
Total Costs
Area of Real Estate Property	780,540
[1]	The aggregate cost of real estate for federal income tax purposes is not materially different from the cost basis under GAAP (unaudited).
[2]	The depreciable life for buildings and improvements ranges from 30 to 40 years, 20 for land improvements, and the term of the respective lease for tenant improvement.
[3]	Loan of $30,377 secured by four properties identified by this reference.
[4]	Loan of $77,316 secured by six properties identified by this reference.
[5]	Loan of $129,367 secured by four properties identified by this reference.
[6]	Loan of $113,567 secured by six properties identified by this reference.
[7]	The balance shown includes an unamortized premium of $242.
[8]	The balance shown includes an unamortized premium of $27.
[9]	Represents land and land improvements in Toronto, Canada that were classified in rental properties. This real estate was leased to a tenant and the tenant was completing the construction of a 780,540 RSF building. In December 2014, we determined that this property met the criteria to be classified as “held for sale”. In January 2015, we completed the sale

Schedule_III_Consolidated_Fina2

Schedule III - Consolidated Financial Statement Schedule of Rental Properties and Accumulated Depreciation Rollforward (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Rental Properties and Current, Near-Term and Future Value-Creation Projects
Balance at end of period	$8,346,261	[1]
Accumulated Depreciation
Balance at beginning of period	952,106		875,035	742,535
Depreciation expense on properties	183,432		149,848	157,193
Write off of fully amortized properties	0		0	-17,730
Sale of properties	-15,293		-72,777	-6,963
Balance at end of period	1,120,245	[2]	952,106	875,035
Rental Properties [Member]
Rental Properties and Current, Near-Term and Future Value-Creation Projects
Balance at beginning of period	6,442,208		5,645,771	5,112,759
Purchase of real estate	95,400		118,892	42,901
Sale of real estate	-7,541		-182,037	-30,807
Write-off of fully amortized improvements	0		0	-17,730
Additions and net transfers from land held for future development and construction in progress	458,246		859,582	538,648
Balance at end of period	6,988,313		6,442,208	5,645,771
Current, Near-Term and Future Value-Creation Projects [Member]
Rental Properties and Current, Near-Term and Future Value-Creation Projects
Balance at beginning of period	1,286,812		1,653,842	1,638,216
Purchase of real estate	69,944		11,422	0
Sale of real estate	-94,581		-67,880	-14,655
Balance at end of period	1,357,948		1,286,812	1,653,842
Transfer from CIP to Rental Properties [Member] | Current, Near-Term and Future Value-Creation Projects [Member]
Rental Properties and Current, Near-Term and Future Value-Creation Projects
Additions and net transfers from land held for future development and construction in progress	-458,246		-859,582	-538,648
Change in Real Estate JV [Member] | Current, Near-Term and Future Value-Creation Projects [Member]
Rental Properties and Current, Near-Term and Future Value-Creation Projects
Additions and net transfers from land held for future development and construction in progress	70,762		17,988	-13,686
Additions to CIP [Member] | Current, Near-Term and Future Value-Creation Projects [Member]
Rental Properties and Current, Near-Term and Future Value-Creation Projects
Additions and net transfers from land held for future development and construction in progress	$483,257		$531,022	$582,615
[1]	The aggregate cost of real estate for federal income tax purposes is not materially different from the cost basis under GAAP (unaudited).
[2]	The depreciable life for buildings and improvements ranges from 30 to 40 years, 20 for land improvements, and the term of the respective lease for tenant improvement.