Alexandria Real Estate Equities (ARE) 10-Q31 Jul 182018 Q2 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2018	Jul. 16, 2018
Document and Entity Information
Entity Registrant Name	ALEXANDRIA REAL ESTATE EQUITIES INC
Entity Central Index Key	1,035,443
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		105,757,371
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Assets
Investments in real estate	$ 11,190,771	$ 10,298,019
Investments in unconsolidated real estate joint ventures	192,972	110,618
Cash and cash equivalents	287,029	254,381
Restricted cash	34,812	22,805
Tenant receivables	8,704	10,262
Deferred rent	490,428	434,731
Deferred leasing costs	232,964	221,430
Investments	790,753	523,254
Other assets	333,757	228,453
Total assets	13,562,190	12,103,953
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	776,260	771,061
Unsecured senior notes payable	4,289,521	3,395,804
Unsecured senior line of credit	0	50,000
Unsecured senior bank term loans	548,324	547,942
Accounts payable, accrued expenses, and tenant security deposits	849,274	763,832
Dividends payable	98,676	92,145
Total liabilities	6,562,055	5,620,784
Commitments and contingencies
Redeemable noncontrolling interests	10,861	11,509
Alexandria Real Estate Equities, Inc.’s stockholders’ equity:
7.00% Series D cumulative convertible preferred stock	74,386	74,386
Common stock	1,033	998
Additional paid-in capital	6,387,527	5,824,258
Accumulated other comprehensive (loss) income	(2,485)	50,024
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	6,460,461	5,949,666
Noncontrolling interests	528,813	521,994
Total equity	6,989,274	6,471,660
Total liabilities, noncontrolling interests, and equity	$ 13,562,190	$ 12,103,953

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue	$ 325,034	$ 273,059	$ 645,173	$ 543,936
Expenses:
Rental operations	91,908	76,980	183,679	154,067
General and administrative	22,939	19,234	45,360	38,463
Interest	38,097	31,748	75,012	61,532
Depreciation and amortization	118,852	104,098	233,071	201,281
Impairment of real estate	6,311	203	6,311	203
Loss on early extinguishment of debt	0	0	0	670
Total expenses	278,107	232,263	543,433	456,216
Equity in earnings of unconsolidated real estate joint ventures	1,090	589	2,234	950
Investment income	12,530	0	98,091	0
Gain on sales of real estate – rental properties	0	0	0	270
Gain on sales of real estate – land parcels	0	111	0	111
Net income	60,547	41,496	202,065	89,051
Net income attributable to noncontrolling interests	(5,817)	(7,275)	(11,705)	(13,119)
Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	54,730	34,221	190,360	75,932
Dividends on preferred stock	(1,302)	(1,278)	(2,604)	(5,062)
Preferred stock redemption charge	0	0	0	(11,279)
Net income attributable to unvested restricted stock awards	(1,412)	(1,313)	(2,765)	(2,300)
Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	$ 52,016	$ 31,630	$ 184,991	$ 57,291
Earnings per share attributable to Alexandria’s common stockholders – basic and diluted:
Earnings per share – basic (USD per share)	$ 0.51	$ 0.35	$ 1.83	$ 0.64
Earnings per shares - diluted (USD per share)	0.51	0.35	1.83	0.64
Dividends declared per share of common stock (USD per share)	$ 0.93	$ 0.86	$ 1.83	$ 1.69
Rental revenues
Revenue	$ 250,635	$ 211,942	$ 495,120	$ 419,135
Tenant recoveries
Revenue	72,159	60,470	145,329	121,816
Other income
Revenue	$ 2,240	$ 647	$ 4,724	$ 2,985

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 60,547	$ 41,496	$ 202,065	$ 89,051
Unrealized (losses) gains on public investments:
Unrealized holding (losses) gains arising during the period	0	(4,025)	0	6,396
Reclassification adjustment for losses included in net income	0	2,349	0	2,482
Unrealized (losses) gains on public investments, net	0	(1,676)	0	8,878
Unrealized (losses) gains on interest rate hedge agreements:
Unrealized interest rate hedge gains (losses) arising during the period	661	(550)	2,643	667
Reclassification adjustment for amortization of interest (income) expense included in net income	(1,131)	707	(1,809)	1,612
Unrealized (losses) gains on interest rate hedge agreements, net	(470)	157	834	2,279
Unrealized (losses) gains on foreign currency translation:
Unrealized foreign currency translation (losses) gains arising during the period	(3,243)	2,744	(3,572)	3,756
Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation	0	0	0	2,421
Unrealized (losses) gains on foreign currency translation, net	(3,243)	2,744	(3,572)	6,177
Total other comprehensive (loss) income	(3,713)	1,225	(2,738)	17,334
Comprehensive income (loss)	56,834	42,721	199,327	106,385
Less: comprehensive income attributable to noncontrolling interests	(5,817)	(7,283)	(11,705)	(13,131)
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	$ 51,017	$ 35,438	$ 187,622	$ 93,254

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders' Equity and Noncontrolling Interests (Unaudited) - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Noncontrolling Interests	Redeemable Noncontrolling Interests	7.00% Series D Cumulative Convertible Preferred StockPreferred Stock
Beginning balance (shares) at Dec. 31, 2017		99,783,686
Beginning balance at Dec. 31, 2017	$ 6,471,660	$ 998	$ 5,824,258	$ 0	$ 50,024	$ 521,994		$ 74,386
Increase (Decrease) in Stockholders' Equity
Net Income	201,640			190,360		11,280
Total other comprehensive loss	(2,738)				(2,738)
Reclassification of cumulative net unrealized gains on non-real estate investments	90,750			140,521	(49,771)
Distributions to noncontrolling interests	(18,018)					(18,018)
Sale of and contributions from noncontrolling interests	13,814		257			13,557
Issuances of common stock shares		3,299,637
Issuance of common stock	400,207	$ 33	400,174
Issuances pursuant to stock plan (in shares)		262,794
Issuances pursuant to stock plan	24,134	$ 2	24,132
Dividends declared on common stock	(189,571)			(189,571)
Dividends declared on preferred stock	(2,604)			(2,604)
Distributions in excess of earnings	0		138,706	(138,706)
Ending balance (shares) at Jun. 30, 2018		103,346,117
Ending balance at Jun. 30, 2018	6,989,274	$ 1,033	$ 6,387,527	$ 0	$ (2,485)	$ 528,813		$ 74,386
Beginning balance at Dec. 31, 2017	11,509						$ 11,509
Increase (Decrease) in Temporary Equity [Roll Forward]
Net Income							425
Redemption of noncontrolling interest							(1,397)
Distributions to noncontrolling interests							(426)
Contribution from noncontrolling interests							750
Ending balance at Jun. 30, 2018	$ 10,861						$ 10,861

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net income (loss)	$ 202,065	$ 89,051
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	233,071	201,281
Loss on early extinguishment of debt	0	670
Gain on sales of real estate – rental properties	0	(270)
Impairment of real estate	6,311	203
Gain (loss) on sale of real estate - land parcels	0	(111)
Equity in earnings of unconsolidated real estate joint ventures	(2,234)	(950)
Distributions of earnings from unconsolidated real estate joint ventures	287	249
Amortization of loan fees	5,136	5,738
Amortization of debt discounts (premiums)	(1,181)	(1,221)
Amortization of acquired below-market leases	(11,368)	(10,363)
Deferred rent	(55,890)	(53,497)
Stock compensation expense	15,223	10,756
Investment income	(98,091)	(962)
Changes in operating assets and liabilities:
Tenant receivables	1,552	1,354
Deferred leasing costs	(29,705)	(26,811)
Other assets	(15,055)	(4,654)
Accounts payable, accrued expenses, and tenant security deposits	8,120	13,283
Net cash provided by operating activities	258,241	223,746
Investing Activities
Proceeds from sale of properties	0	3,528
Additions to real estate	(431,225)	(436,377)
Purchases of real estate	(688,698)	(480,543)
Deposits for investing activities	5,500	450
Acquisition of interest in unconsolidated joint venture	35,922	0
Investments in unconsolidated real estate joint ventures	(44,486)	(163)
Additions to investments	(118,775)	(81,192)
Sales of investments	44,707	12,577
Net cash used in investing activities	(1,268,899)	(981,720)
Financing Activities
Borrowings from secured notes payable	9,044	117,666
Repayments of borrowings from secured notes payable	(3,162)	(1,677)
Proceeds from issuance of unsecured senior notes payable	899,321	424,384
Borrowings from unsecured senior line of credit	2,469,000	2,069,000
Repayments of borrowings from unsecured senior line of credit	(2,519,000)	(1,797,000)
Repayments of borrowings from unsecured senior bank term loans	0	(200,000)
Payment of loan fees	(8,003)	(4,344)
Repurchase of Series D preferred stock	0	(17,934)
Redemption of Series E preferred stock	0	(130,350)
Proceeds from the issuance of common stock	400,207	459,607
Dividends on common stock	(183,040)	(149,296)
Dividends on preferred stock	(2,604)	(7,015)
Contributions from noncontrolling interests	14,564	8,505
Distributions to and purchases of noncontrolling interests	(19,841)	(10,791)
Net cash provided by financing activities	1,056,486	760,755
Effect of foreign exchange rate changes on cash and cash equivalents	(1,173)	732
Net (decrease) increase in cash, cash equivalents, and restricted cash	44,655	3,513
Cash, cash equivalents, and restricted cash, beginning of period	277,186	141,366
Cash, cash equivalents, and restricted cash, end of period	321,841	144,879
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized	68,885	53,810
Non-Cash Investing Activities
Change in accrued construction	48,074	(25,138)
Contribution of real estate to an unconsolidated real estate joint venture	$ 0	$ 6,998

Organization and basis of prese

Organization and basis of presentation	6 Months Ended
Organization and basis of presentation	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and basis of presentation	Organization and basis of presentation Alexandria Real Estate Equities, Inc. (NYSE:ARE), an S&P 500 ® company, is an urban office REIT uniquely focused on collaborative life science and technology campuses in AAA innovation cluster locations. As used in this quarterly report on Form 10‑Q , references to the “Company,” “Alexandria,” “ARE,” “we,” “us,” and “our” refer to Alexandria Real Estate Equities, Inc. and its consolidated subsidiaries. The accompanying unaudited consolidated financial statements include the accounts of Alexandria Real Estate Equities, Inc. and its consolidated subsidiaries. All significant intercompany balances and transactions have been eliminated. We have prepared the accompanying interim consolidated financial statements in accordance with GAAP and in conformity with the rules and regulations of the SEC. In our opinion, the interim consolidated financial statements presented herein reflect all adjustments, of a normal recurring nature, that are necessary to fairly present the interim consolidated financial statements. The results of operations for the interim period are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 . These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in our annual report on Form 10‑K for the year ended December 31, 2017 . Any references to our market capitalization, number or quality of buildings or tenants, quality of location, square footage, number of leases, or occupancy percentage, and any amounts derived from these values in the notes to consolidated financial statements, are outside the scope of our independent registered public accounting firm’s interim review.

Summary of significant accounti

Summary of significant accounting policies	6 Months Ended
Summary of significant accounting policies	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of significant accounting policies	Summary of significant accounting policies Consolidation On an ongoing basis, as circumstances indicate the need for reconsideration, we evaluate each legal entity that is not wholly owned by us in accordance with the consolidation guidance. Our evaluation considers all of our variable interests, including equity ownership, as well as fees paid to us for our involvement in the management of each partially owned entity. To fall within the scope of the consolidation guidance, an entity must meet both of the following criteria: • The entity has a legal structure that has been established to conduct business activities and to hold assets; such entity can be in the form of a partnership, limited liability company, or corporation, among others; and • We have a variable interest in the legal entity – i.e., variable interests that are contractual, such as equity ownership, or other financial interests that change with changes in the fair value of the entity’s net assets. If an entity does not meet both criteria above, we apply other accounting literature, such as the cost or equity method of accounting. If an entity does meet both criteria above, we evaluate such entity for consolidation under either the variable interest model if the legal entity meets any of the following characteristics to qualify as a VIE, or under the voting model for all other legal entities that are not VIEs. A legal entity is determined to be a VIE if it has any of the following three characteristics: 1) The entity does not have sufficient equity to finance its activities without additional subordinated financial support; 2) The entity is established with non-substantive voting rights (i.e., where the entity deprives the majority economic interest holder(s) of voting rights); or 3) The equity holders, as a group, lack the characteristics of a controlling financial interest. Equity holders meet this criterion if they lack any of the following: • The power, through voting rights or similar rights, to direct the activities of the entity that most significantly influence the entity’s economic performance, as evidenced by: • Substantive participating rights in day-to-day management of the entity’s activities; or • Substantive kick-out rights over the party responsible for significant decisions; • The obligation to absorb the entity’s expected losses; or • The right to receive the entity’s expected residual returns. Once we consider the sufficiency of equity and voting rights of each legal entity, we then evaluate the characteristics of the equity holders’ interests, as a group, to see if they qualify as controlling financial interests. Our real estate joint ventures consist of limited partnerships or limited liability companies. For an entity structured as a limited partnership or a limited liability company, our evaluation of whether the equity holders (equity partners other than us in each of our joint ventures) lack the characteristics of a controlling financial interest includes the evaluation of whether the limited partners or non-managing members (the noncontrolling equity holders) lack both substantive participating rights and substantive kick-out rights, defined as follows: • Participating rights provide the noncontrolling equity holders the ability to direct significant financial and operating decisions made in the ordinary course of business that most significantly influence the entity’s economic performance. • Kick-out rights allow the noncontrolling equity holders to remove the general partner or managing member without cause. If we conclude that any of the three characteristics of a VIE are met, including that the equity holders lack the characteristics of a controlling financial interest because they lack both substantive participating rights and substantive kick-out rights, we conclude that the entity is a VIE and evaluate it for consolidation under the variable interest model. Variable interest model If an entity is determined to be a VIE, we evaluate whether we are the primary beneficiary. The primary beneficiary analysis is a qualitative analysis based on power and benefits. We consolidate a VIE if we have both power and benefits – that is, (i) we have the power to direct the activities of a VIE that most significantly influence the VIE’s economic performance (power), and (ii) we have the obligation to absorb losses of or the right to receive benefits from the VIE that could potentially be significant to the VIE (benefits). We consolidate VIEs whenever we determine that we are the primary beneficiary. Refer to Note 4 – “Consolidated and Unconsolidated Real Estate Joint Ventures” to these unaudited consolidated financial statements for information on specific joint ventures that qualify as VIEs. If we have a variable interest in a VIE but we are not the primary beneficiary, we account for our investment using the equity method of accounting. Voting model If a legal entity fails to meet any of the three characteristics of a VIE (due to insufficiency of equity, existence of non-substantive voting rights, or lack of a controlling financial interest), we then evaluate such entity under the voting model. Under the voting model, we consolidate the entity if we determine that we, directly or indirectly, have greater than 50% of the voting shares and that other equity holders do not have substantive participating rights. Refer to Note 4 – “Consolidated and Unconsolidated Real Estate Joint Ventures” to these unaudited consolidated financial statements for further information on our unconsolidated real estate joint ventures that qualify for evaluation under the voting model. 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. Investments in real estate Evaluation of business combination or asset acquisition We evaluate each acquisition of real estate or in-substance real estate (including equity interests in entities that predominantly hold real estate assets) to determine whether the integrated set of assets and activities acquired meets the definition of a business and needs to be accounted as a business combination. An acquisition of an integrated set of assets and activities that does not meet the definition of a business is accounted for as an asset acquisition. If either of the following criteria is met, the integrated set of assets and activities acquired would not qualify as a business: • Substantially all of the fair value of the gross assets acquired is concentrated in either a single identifiable asset or a group of similar identifiable assets; or • The integrated set of assets and activities is lacking, at a minimum, an input and a substantive process that together significantly contribute to the ability to create outputs (i.e., revenue generated before and after the transaction). An acquired process is considered substantive if: • The process includes an organized workforce (or includes an acquired contract that provides access to an organized workforce) that is skilled, knowledgeable, and experienced in performing the process; • The process cannot be replaced without significant cost, effort, or delay; or • The process is considered unique or scarce. Generally, we expect that acquisitions of real estate or in-substance real estate will not meet the definition of a business because substantially all of the fair value is concentrated in a single identifiable asset or group of similar identifiable assets (i.e., land, buildings, and related intangible assets) or because the acquisition does not include a substantive process in the form of an acquired workforce or an acquired contract that cannot be replaced without significant cost, effort, or delay. When evaluating acquired service or management contracts, we consider the nature of the services performed, the terms of the contract relative to similar arm’s-length contracts, and the availability of comparable vendors in evaluating whether the acquired contract constitutes a substantive process. Recognition of real estate acquired For acquisitions of real estate or in-substance real estate that are accounted for as business combinations, we recognize the assets acquired (including the intangible value of acquired above- or below-market leases, acquired in-place leases, tenant relationships, and other intangible assets or liabilities), liabilities assumed, noncontrolling interests, and previously existing ownership interests at fair value as of the acquisition date. Any excess (deficit) of the consideration transferred relative to the fair value of the net assets acquired is accounted for as goodwill (bargain purchase gain). Acquisition costs related to business combinations are expensed as incurred. Acquisitions of real estate and in-substance real estate that do not meet the definition of a business are accounted for as asset acquisitions. The accounting model for asset acquisitions is similar to the accounting model for business combinations except that the acquisition consideration (including acquisition costs) is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis. As a result, asset acquisitions do not result in the recognition of goodwill or a bargain purchase gain. Additionally, because the accounting model for asset acquisitions is a cost accumulation model, preexisting interests in the acquired assets, if any, are not remeasured to fair value but continue to be accounted for at their historical cost. Direct acquisition costs are capitalized if an asset acquisition is probable. If we determine that an asset acquisition is no longer probable, no new costs are capitalized and all capitalized costs that are not recoverable are expensed. The relative fair values used to allocate the cost of an asset acquisition are determined by the same methodologies and assumptions we utilize to determine fair value in a business combination. If a real estate property is acquired with an in-place lease that contains a bargain fixed-rate renewal option for the period beyond the non-cancelable lease term, 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 its space 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 renewal option will be exercised, we consider the option 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 under the 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. 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 up to 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 increases (for below-market leases) or decreases (for above-market leases) to rental revenue. The values of acquired above- and below-market ground leases are amortized over the terms of the related ground leases and recognized as either increases (for below-market ground leases) or decreases (for above-market ground leases) to rental operating expense. 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. Capitalized project costs We capitalize project costs, including pre-construction costs, interest, property taxes, insurance, and other costs directly related and essential to the development, redevelopment, pre-construction, or construction of a project. Capitalization of development, redevelopment, pre-construction, and construction costs is required while activities are ongoing to prepare an asset for its intended use. Fluctuations in our development, redevelopment, pre-construction, 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, pre-construction, 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. Real estate sales 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. If the disposal of a 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, 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 will typically not meet the criteria for classification as a discontinued operation. Impairment of long-lived assets 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, if necessary, a probability-weighted approach if multiple outcomes are under consideration. 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 carrying amount of a long-lived asset may not be recoverable. The carrying 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, land held for development, and intangibles, are assessed by project and include significant fluctuations in estimated net operating income, 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 carrying 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. International operations In addition to operating properties in the U.S., we have three operating properties in Canada and one operating property in China. The functional currency for our subsidiaries operating in the U.S. is the U.S. dollar. 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 weighted-average exchange rate for the periods presented. Gains or losses resulting from the translation are classified in accumulated other comprehensive income as a separate component of total equity. Whenever a foreign investment meets the criteria for classification as held for sale, we evaluate the recoverability of the investment under the held for sale impairment model. We may recognize an impairment charge if the carrying amount of the investment exceeds its fair value less cost to sell. In determining an investment’s carrying amount, we consider its net book value and any cumulative unrealized foreign currency translation adjustment related to the investment. The appropriate amounts of foreign exchange rate gains or losses classified in accumulated other comprehensive income are reclassified to net income when realized upon the sale of our investment or upon the complete or substantially complete liquidation of our investment. Investments We hold investments in publicly traded companies and privately held entities primarily involved in the life science and technology industries. As a REIT, we generally limit our ownership percentage in the voting stock of each individual entity to less than 10% . Prior to January 1, 2018 Prior to the adoption of a new ASU on financial instruments effective January 1, 2018, all of our equity investments in actively traded public companies were considered available-for-sale and were presented in the accompanying consolidated balance sheets at fair value. Fair value was determined based upon the closing price as of each balance sheet date, with unrealized gains and losses shown as a separate component of accumulated other comprehensive income within total equity (excluded from net income). The classification of each investment was determined at the time each investment was made, and such determination was reevaluated at each balance sheet date. The cost of each investment sold was 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 were generally accounted for under the cost method when our interest in the entity was so minor that we had virtually no influence over the entity’s operating and financial policies. Investments in privately held entities were accounted for under the equity method unless our interest in the entity was deemed to be so minor that we had virtually no influence over the entity’s operating and financial policies. Under the equity method of accounting, we recognized our investment initially at cost and adjusted the carrying amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment. We periodically assessed our investments in available-for-sale equity securities and privately held companies accounted for under the cost method for other-than-temporary impairment. We monitored each of our investments throughout the year for new developments, including operating results, results of clinical trials, capital-raising events, and merger and acquisition activities. Individual investments were evaluated for impairment when changes in conditions indicated an impairment may exist. The factors that we considered in making these assessments included, but were 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 an unrealized loss related to an available-for-sale equity security was determined to be other-than-temporary, such unrealized loss was reclassified from accumulated other comprehensive income within total equity into earnings. For a cost method investment, if a decline in the fair value of an investment below its carrying value was determined to be other-than-temporary, such investment was written down to its estimated fair value with a charge to earnings. If there were no identified events or changes in circumstances that might have had an adverse effect on our cost method investments, we did not estimate the investment’s fair value. Effective January 1, 2018 Beginning on January 1, 2018, under the new ASU, equity investments (except those accounted for under the equity method and those that result in consolidation of the investee) are measured at fair value, with changes in fair value recognized in net income, as follows: • Investments in publicly traded companies are classified as investments with readily determinable fair values. These investments are carried at fair value, with changes in fair value recognized in net income, rather than in accumulated other comprehensive income within total equity. The fair values for our investments in publicly traded companies continue to be determined based on sales prices/quotes available on securities exchanges, or published prices that serve as the basis for current transactions. • Investments in privately held entities without readily determinable fair values fall into two categories: • Investments in privately held entities that report net asset value per share (“NAV”), such as our privately held investments in limited partnerships, are carried at fair value using NAV as a practical expedient with changes in fair value recognized in net income. • Investments in privately held entities that do not report NAV are accounted for using a measurement alternative which allows these investments to be measured at cost, adjusted for observable price changes and impairments, with changes recognized in net income. For investments in privately held entities that do not report NAV, an observable price is a price observed in an orderly transaction for an identical or similar investment of the same issuer. Observable price changes result from, among other things, equity transactions for the same issuer executed during the reporting period, including subsequent equity offerings or other reported equity transactions related to the same issuer. For these transactions to be considered observable price changes, we evaluate whether these transactions have similar rights and obligations, including voting rights, distribution preferences, conversion rights, and other factors, to the investments we hold. Investments in privately held entities that do not report NAV continue to be evaluated on the basis of a qualitative assessment for indicators of impairment by utilizing the same monitoring criteria described above. If such indicators are present, we are required to estimate the investment’s fair value and immediately recognize an impairment loss, without consideration as to whether the impairment is other-than-temporary, in an amount equal to the investment’s carrying value in excess of its estimated fair value. Investments in privately held entities continue to be 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 initially recognize our investment at cost and adjust the carrying amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment. Initial adoption of new ASU On January 1, 2018, we recognized the following adjustments upon adoption of the new ASU: • For investments in publicly traded companies, reclassification of cumulative unrealized gains as of December 31, 2017, aggregating $49.8 million , from accumulated other comprehensive income to retained earnings. • For investments in privately held entities without readily determinable fair values that were previously accounted for under the cost method: • Adjustment to investments for unrealized gains aggregating $90.8 million related to investments in privately held entities that report NAV, representing the difference between fair value as of December 31, 2017, using NAV as a practical expedient and the carrying value of the investments as of December 31, 2017, with a corresponding adjustment to retained earnings. • No adjustment was required for investments in privately held entities that do not report NAV. The ASU requires a prospective transition approach for investments in privately held entities that do not report NAV. The FASB clarified that it would be difficult for entities to determine the last observable transaction price existing prior to the adoption of this ASU. Therefore, unlike our investments in privately held entities that report NAV that were adjusted to reflect fair values upon adoption of the new ASU, our investments in privately held entities that do not report NAV were not retrospectively adjusted to fair values upon adoption. As such, any initial valuation adjustments made for investments in privately held entities that do not report NAV subsequent to January 1, 2018, as a result of future observable price changes include recognition of unrealized gains or losses equal to the difference between the carrying basis of the investment and the observable price at the date of remeasurement. Revenue recognition Recognition of revenue arising from contracts with customers On January 1, 2018, we adopted an ASU on revenue recognition that requires a new model for recognition of revenue arising from contracts with customers, as well as recognition of gains and losses from the transfer of nonfinancial assets arising from contracts with noncustomers. A customer is distinguished from a noncustomer by the nature of the goods or services that are transferred. Customers are provided with goods or services that are generated by a company’s ordinary output activities, whereas noncustomers are provided with nonfinancial assets that are outside of a company’s ordinary output activities. The core principle underlying the ASU on recognition of revenue arising from contracts with customers is that an entity must recognize revenue to represent the transfer of goods and services to customers in an amount that reflects the consideration to which the entity expects to be entitled in such exchange. This requires entities to identify contractual performance obligations and determine whether revenue should be recognized at a point in time or over time, based on when control of goods and services transfers to a customer. The ASU requires the use of a new five-step model to recognize revenue from customer contracts. The five-step model requires that we (i) identify the contract with the customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, including variable consideration to the extent that it is probable that a significant future reversal will not occur, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) we satisfy the performance obligation. An entity is also required to determine if it controls the goods or services prior to the transfer to the customer in order to determine if it should account for the arrangement as a principal or agent. Principal arrangements, where the entity controls the goods or services provided, result in the recognition of the gross amount of consideration expected in the exchange. Agent arrangements, where the entity simply arranges but does not control the goods or services being transferred to the customer, result in the recognition of the net amount the entity is entitled to retain in the exchange. Upon adoption of the new lease ASU in 2019, we will be required to classify our tenant recoveries into lease and nonlease components, whereby the nonlease components would be subject to the ASU on recognition of revenue arising from contracts with customers. However, if we elect a practical expedient, as discussed in “Lessor Accounting” within the “Lease Accounting” section of “Recent Accounting Pronouncements” contained in Note 2, tenant recoveries for goods and services that are categorized as nonlease components but have the same timing and pattern of transfer as the related lease component may (subject to the predominance test) be accounted for under the new lease ASU. Tenant recoveries that do not qualify for the practical expedient will be accounted for under the ASU on recognition of revenue arising from contracts with customers upon adoption of the new lease ASU. Property services categorized as nonlease components that are reimbursed by our tenants may need to be presented on a net basis if it is determined that we hold an agent arrangement. Entities had the option to transition to the ASU on recognition of revenue arising from contracts with customers using either the full retrospective or the modified retrospective method. We adopted this ASU using the modified retrospective method, which requires a cumulative adjustment for effects of applying the new standard to periods prior to 2018 to be recorded to retained earnings as of January 1, 2018. We also elected to apply this ASU only to contracts not completed as of January 1, 2018. For all contracts within the scope of this ASU that were not completed as of January 1, 2018, we evaluated the revenue recognition under accounting standards in effect prior to January 1, 2018, and under the new ASU, and determined that amounts recognized and the pattern of revenue recognition were consistent. Therefore, the adoption of the ASU on recognition of revenue arising from contracts with customers did not result i

Investments in real estate

Investments in real estate	6 Months Ended
Investments in real estate	Jun. 30, 2018
Real Estate [Abstract]
Investments in real estate	Investments in real estate Our consolidated investments in real estate consisted of the following as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Land (related to rental properties) $ 1,442,071 $ 1,312,072 Buildings and building improvements 9,559,442 9,000,626 Other improvements 880,549 780,117 Rental properties 11,882,062 11,092,815 Development and redevelopment of new Class A properties: Development and redevelopment projects (under construction, marketing, or pre-construction) 1,253,419 955,218 Future development projects 92,473 96,112 Gross investments in real estate 13,227,954 12,144,145 Less: accumulated depreciation (2,066,333 ) (1,875,810 ) Net investments in real estate – North America 11,161,621 10,268,335 Net investments in real estate – Asia 29,150 29,684 Investments in real estate $ 11,190,771 $ 10,298,019 Acquisitions Our real estate asset acquisitions during the six months ended June 30, 2018 and subsequently, consisted of the following (dollars in thousands): Square Footage Three Months Ended Operating Operating with Active or Future Redevelopment Active or Future Purchase Price March 31, 2018 487,227 106,733 643,765 $ 339,400 June 30, 2018 782,388 39,505 793,000 405,855 Subsequent acquisitions 45,626 349,947 217,000 257,000 1,315,241 496,185 1,653,765 $ 1,002,255 We evaluated each of the transactions detailed below to determine whether the integrated set of assets and activities acquired met the definition of a business. Acquisitions that do not meet the definition of a business are accounted for as asset acquisitions. An integrated set of assets and activities does not qualify as a business if substantially all of the fair value of the gross assets is concentrated in either a single identifiable asset or a group of similar identifiable assets, or if the acquired assets do not include a substantive process. We evaluated each of the completed acquisitions and determined that substantially all of the fair value related to each acquisition is concentrated in a single identifiable asset or a group of similar identifiable assets, or is a land parcel with no operations. Accordingly, each transaction did not meet the definition of a business and consequently was accounted for as an asset acquisition. In each of these transactions, we allocated the total consideration for each acquisition to the individual assets and liabilities acquired on a relative fair value basis. Active or future development 1655 and 1725 Third Street – Mission Bay/SoMa, San Francisco In March 2018, we acquired a 10% interest in a real estate joint venture with Uber Technologies, Inc. (“Uber”) and the Golden State Warriors that owns 1655 and 1725 Third Street, located in our Mission Bay/SoMa submarket of San Francisco. The joint venture is developing two buildings aggregating 593,765 RSF that are integrated within the new Golden State Warriors complex under development. The buildings are 100% leased to Uber. At the closing of the joint venture agreement, we contributed equity totaling $32.0 million . Refer to Note 4 – “Consolidated and Unconsolidated Real Estate Joint Ventures” to these unaudited consolidated financial statements for additional information. Other acquisitions During the three months ended June 30, 2018 , we acquired one building and four land parcels in five transactions for an aggregate purchase price of $58.2 million in key submarkets with development and redevelopment opportunities of 493,000 RSF. Operating with active or future development Summers Ridge Science Park – Sorrento Mesa, San Diego In January 2018, we acquired Summers Ridge Science Park, a campus with on-site amenities and four operating properties aggregating 316,531 RSF of office/laboratory space, located at 9965, 9975, 9985, and 9995 Summers Ridge Road in our Sorrento Mesa submarket of San Diego, for a purchase price of $148.7 million . The property also includes a future development opportunity for an additional 50,000 RSF building. The properties are 100% leased as of June 30, 2018 , to two life science product, service, and device companies for 15 years . Alexandria PARC – Greater Stanford, San Francisco In January 2018, we acquired Alexandria PARC, a four-building office campus, aggregating 197,498 RSF, on 11 acres, located at 2100, 2200, 2300, and 2400 Geng Road in our Greater Stanford submarket of San Francisco, for a purchase price of $136.0 million . The property has 14 in-place leases with a weighted-average remaining lease term of three years . We are redeveloping 48,547 RSF into office/laboratory space. 100 Tech Drive – Route 128, Greater Boston In April 2018, we acquired a Class A office/laboratory building aggregating 200,431 RSF, located at 100 Tech Drive in our Route 128 submarket of Greater Boston, for a purchase price of $87.3 million . The property is 100% leased by Moderna Therapeutics under a 14.5 -year lease. The property can also accommodate future development of an additional 300,000 RSF building. 704 Quince Orchard Road – Rockville/Gaithersburg, Maryland In March 2018, we acquired a 56.8% interest in 704 Quince Orchard Road, an office building aggregating 79,931 RSF, located in our Gaithersburg submarket of Maryland, for a purchase price of $3.9 million . The building is an expansion of the Alexandria Technology Center ® – Gaithersburg II campus. We are redeveloping 58,186 RSF from existing office space into office/laboratory space. Refer to Note 4 – “Consolidated and Unconsolidated Real Estate Joint Ventures” to these unaudited consolidated financial statements for additional information. Operating Maryland Life Science Portfolio – Rockville/Gaithersburg, Maryland In May 2018, we acquired an eight -building office/laboratory portfolio aggregating 415,611 RSF, located in our Rockville and Gaithersburg submarkets of Maryland, for a purchase price of $146.5 million . These properties are 100% leased with in-place leases that have below-market rental rates and a weighted-average remaining lease term of 5.7 years. 2301 5th Avenue – Lake Union, Seattle In June 2018, we acquired 2301 5th Avenue, an office building aggregating 197,136 RSF, located in our Lake Union submarket of Seattle, for a purchase price of $95.0 million . The property is subject to a 54 -year ground lease. The building is 97.4% occupied with substantially all investment-grade tenants under three in-place leases where rental rates are currently 25% below market, and a weighted-average remaining lease term of 5.5 years. July 2018 acquisitions During July 2018, we acquired three properties for an aggregate purchase price of $257.0 million , including $203.0 million for a fee simple interest in an office building aggregating 349,947 RSF located in New York City, which is currently occupied by Pfizer Inc. with a remaining lease term of six years. Under the Midtown East Rezoning, this property is currently entitled with an as-of-right density for an additional 230,000 developable square feet. Sales of real estate assets During the three months ended June 30, 2018 , we classified a land parcel located in Northern Virginia as held for sale. As a result, we recognized an impairment charge of $6.3 million to lower the carrying amount to the estimated fair value less selling costs during the three months ended June 30, 2018 . We completed the sale, at a price of $6.0 million , in July 2018 with no gain or loss. In January 2017, we completed the sale of a vacant property at 6146 Nancy Ridge Drive located in our Sorrento Mesa submarket of San Diego for a sales price of $3.0 million and recognized a gain of $270 thousand . In June 2017, we recognized an impairment charge of $203 thousand on a 20,580 RSF property located in a non-cluster market. We completed the sale of this property in July 2017 for a gross sales price of $800 thousand with no gain or loss.

Consolidated and unconsolidated

Consolidated and unconsolidated real estate joint ventures	6 Months Ended
Consolidated and unconsolidated real estate joint ventures	Jun. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure	Consolidated and unconsolidated real estate joint ventures From time to time, we enter into joint venture agreements through which we own a partial interest in real estate entities that own, develop, and operate real estate properties. As of June 30, 2018 , we had the following properties that were held by our real estate joint ventures: Property (1) Market Submarket Our Ownership Interest RSF Consolidated joint ventures: 225 Binney Street Greater Boston Cambridge 30.0 % 305,212 409 and 499 Illinois Street San Francisco Mission Bay/SoMa 60.0 % 455,069 1500 Owens Street San Francisco Mission Bay/SoMa 50.1 % 158,267 Campus Pointe by Alexandria San Diego University Town Center 55.0 % 798,799 9625 Towne Centre Drive San Diego University Town Center 50.1 % 163,648 Unconsolidated joint ventures: Menlo Gateway San Francisco Greater Stanford 29.4 % 772,983 1401/1413 Research Boulevard Maryland Rockville 65.0 % (2) (3) 360 Longwood Avenue Greater Boston Longwood Medical Area 27.5 % 210,709 704 Quince Orchard Road Maryland Gaithersburg 56.8 % (2) 79,931 1655 and 1725 Third Street San Francisco Mission Bay/SoMa 10.0 % 593,765 (1) In addition to the real estate joint ventures listed, various partners hold insignificant noncontrolling interests in four other properties in North America. (2) Represents our ownership interest; our voting interest is limited to 50%. (3) Joint venture with a distinguished retail real estate developer for the development of a 90,000 RSF retail shopping center. Our consolidation policy is fully described under the “Consolidation” section within Note 2 – “Summary of Significant Accounting Policies” to these unaudited consolidated financial statements. Consolidation accounting is highly technical, but its framework is primarily based on the controlling financial interests and benefits of the joint ventures. We generally consolidate a joint venture that is a legal entity that we control (i.e., we have the power to direct the activities of the joint venture that most significantly affect its economic performance) through contractual rights, regardless of our ownership interest, and where we determine that we have benefits through the allocation of earnings or losses and fees paid to us that could be significant to the joint venture (the “VIE model”). We also generally consolidate joint ventures when we have a controlling financial interest through voting rights and where our voting interest is greater than 50% (the “voting model”). Voting interest differs from ownership interest for some joint ventures. We account for joint ventures that do not meet the consolidation criteria under the equity method of accounting by recognizing our share of income and losses. The table below shows our categorization of our existing joint ventures under the consolidation framework: Property Consolidation Model Voting Interest Consolidation Analysis Conclusion 225 Binney Street VIE model Not applicable under VIE model We have control and benefits that can be significant to the joint venture; therefore, we are the primary beneficiary of each VIE Consolidated 409 and 499 Illinois Street 1500 Owens Street Campus Pointe by Alexandria 9625 Towne Centre Drive Menlo Gateway We do not control the joint venture and therefore are not the primary beneficiary Equity method of accounting 1401/1413 Research Boulevard 360 Longwood Avenue Voting model Does not exceed 50% Our voting interest is 50% or less 704 Quince Orchard Road 1655 and 1725 Third Street Consolidated VIEs’ balance sheet information The table below aggregates the balance sheet information of our consolidated VIEs as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Investments in real estate $ 1,097,759 $ 1,047,472 Cash and cash equivalents 40,352 41,112 Other assets 70,595 68,754 Total assets $ 1,208,706 $ 1,157,338 Secured notes payable $ — $ — Other liabilities 69,191 52,201 Total liabilities 69,191 52,201 Redeemable noncontrolling interests 749 — Alexandria Real Estate Equities, Inc.’s share of equity 610,996 584,160 Noncontrolling interests’ share of equity 527,770 520,977 Total liabilities and equity $ 1,208,706 $ 1,157,338 In determining whether to aggregate the balance sheet information of our consolidated VIEs, we considered the similarity of each VIE, including the primary purpose of these entities to own, manage, operate, and lease real estate properties owned by the VIEs, and the similar nature of our involvement in each VIE as a managing member. Due to the similarity of the characteristics, we present the balance sheet information of these entities on an aggregated basis. For each of our consolidated VIEs, none of its assets have restrictions that limit their use to settle specific obligations of the VIE. There are no creditors or other partners of our consolidated VIEs that have recourse to our general credit. Our maximum exposure to our consolidated VIEs is limited to our variable interests in each VIE. Unconsolidated real estate joint ventures As of June 30, 2018 , our investments in unconsolidated real estate joint ventures accounted for under the equity method of accounting presented in our consolidated balance sheet consist of the following (in thousands): Property June 30, 2018 Menlo Gateway $ 121,785 1401/1413 Research Boulevard 7,533 360 Longwood Avenue 25,538 704 Quince Orchard Road 4,384 1655 and 1725 Third Street 33,732 $ 192,972 Our maximum exposure to our unconsolidated VIEs is limited to our investment in each VIE. As of June 30, 2018 , our unconsolidated real estate joint ventures have the following non-recourse secured loans that include the following key terms (dollars in thousands): Maturity Date Stated Interest Rate (1) Interest Rate (1)(2) 100% at Joint Venture Level Unconsolidated Joint Venture Our Share Debt Balance (3) Remaining Commitments Menlo Gateway, Phase I 29.4% 3/1/19 L+2.50% 4.49% $ 134,564 $ 13,290 1401/1413 Research Boulevard 65.0% 5/17/20 L+2.50% 5.39% 14,682 9,892 1655 and 1725 Third Street 10.0% 6/29/21 L+3.70% 5.68% 75,520 299,480 360 Longwood Avenue 27.5% 9/1/22 3.32% 3.54% 94,143 17,000 (4) 704 Quince Orchard Road 56.8% 3/16/23 L+1.95% 4.29% 1,016 13,809 Menlo Gateway, Phase II 29.4% 5/1/35 4.53% 4.56% — 157,270 $ 319,925 $ 510,741 (1) For acquired loans, interest rate includes adjustments to reflect the joint venture’s effective borrowing costs at the time of acquisition. (2) Includes interest expense, amortization of loan fees, and amortization of premiums (discounts) as of June 30, 2018 . (3) Represents outstanding principal, net of unamortized deferred financing costs and discount/premium. (4) The remaining loan commitment balance excludes an earn-out advance provision that allows for incremental borrowings up to $48.0 million , subject to certain condition

Cash, cash equivalents, and res

Cash, cash equivalents, and restricted cash	6 Months Ended
Cash, cash equivalents, and restricted cash	Jun. 30, 2018
Cash, cash equivalents, and restricted cash [Abstract]
Cash and Cash Equivalents Disclosure	5. Cash, cash equivalents, and restricted cash Cash, cash equivalents, and restricted cash consisted of the following as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Cash and cash equivalents $ 287,029 $ 254,381 Restricted cash: Funds held in trust under the terms of certain secured notes payable 14,384 12,301 Funds held in escrow related to construction projects and investing activities 16,551 4,546 Other 3,877 5,958 34,812 22,805 Total $ 321,841 $ 277,186

Investments

Investments	6 Months Ended
Investments	Jun. 30, 2018
Investments [Abstract]
Investments	Investments We hold investments in publicly traded companies and privately held entities primarily involved in the life science and technology industries. On January 1, 2018, we adopted a new ASU on financial instruments that prospectively changed how we recognize, measure, present, and disclose these investments. Key differences between prior accounting standards and the new ASU Prior to January 1, 2018: • Investments in publicly traded companies were presented at fair value in the accompanying balance sheet, with changes in fair value recognized in other comprehensive income classified in accumulated other comprehensive income within total equity. • Investments in privately held entities were accounted for under the cost method of accounting. • Gains or losses were recognized in net income upon the sale of an investment. • Investments in privately held entities required accounting under the equity method unless our interest in the entity was deemed to be so minor that we had virtually no influence over the entity’s operating and financial policies. Under the equity method of accounting, we recognized our investment initially at cost and adjusted the carrying amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment. We had no investments accounted for under the equity method as of December 31, 2017. • Investments were evaluated for impairment, with other-than-temporary impairments recognized in net income. Effective January 1, 2018: • Investments in publicly traded companies are presented at fair value in the accompanying balance sheet, with changes in fair value recognized in net income. • Investments in privately held entities without readily determinable fair values previously accounted for under the cost method are accounted for as follows: • Investments in privately held entities that report NAV are presented at fair value using NAV as a practical expedient, with changes in fair value recognized in net income. • Investments in privately held entities that do not report NAV are carried at cost, adjusted for observable price changes and impairments, with changes recognized in net income. • One-time adjustments recognized on January 1, 2018: • For investments in publicly traded companies, reclassification of net unrealized gain as of December 31, 2017, aggregating $49.8 million , from accumulated other comprehensive income to retained earnings. • For investments in privately held entities without readily determinable fair values that were previously accounted for under the cost method: • Adjustment to investments for unrealized gains aggregating $90.8 million related to investments in privately held entities that report NAV, representing the difference between fair value as of December 31, 2017, using NAV as a practical expedient and the carrying value of the investments as of December 31, 2017, with a corresponding adjustment to retained earnings. • No adjustment was required for investments in privately held entities that do not report NAV. The ASU requires a prospective transition approach for investments in privately held entities that do not report NAV. The FASB clarified that it would be difficult for entities to determine the last observable transaction price existing prior to the adoption of this ASU. Therefore, unlike our investments in privately held entities that report NAV that were adjusted to reflect fair values upon adoption of the new ASU, our investments in privately held entities that do not report NAV were not retrospectively adjusted to fair values upon adoption. As such, any initial valuation adjustments made for investments in privately held entities that do not report NAV subsequent to January 1, 2018, as a result of future observable price changes will include recognition of unrealized gains or losses equal to the difference between the carrying basis of the investment and the observable price at the date of remeasurement. • Investments in privately held entities continue to require accounting 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 carrying amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment. We had no investments accounted for under the equity method as of June 30, 2018 . We recognize changes in fair value for investments in publicly traded companies and changes in NAV, as an expedient to estimate fair value, reported by limited partnerships, as unrealized gains and losses within investment income in our consolidated income statements. For investments in privately held entities without readily determinable fair values, we adjust the cost basis, and record an unrealized gain or loss within investment income in our consolidated income statements, whenever such investments have an observable price change. Further adjustments to these revised carrying amounts are not made until another price change, if any, is observed. For further information regarding the new ASU, refer to the “Investments” section within Note 2 – “Summary of Significant Accounting Policies” to these unaudited consolidated financial statements. The following tables summarize our investments as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 Cost Adjustments Carrying Amount Investments at fair value: Publicly traded companies $ 101,603 $ 97,013 $ 198,616 Entities that report NAV 173,813 110,843 284,656 Entities that do not report NAV: Entities with observable price changes since January 1, 2018 12,811 10,289 23,100 Entities without observable price changes 284,381 — 284,381 Total investments $ 572,608 $ 218,145 $ 790,753 December 31, 2017 Cost Adjustments Total Investments in publicly traded companies $ 59,740 $ 49,771 $ 109,511 Investments in privately held entities without readily determinable fair values (cost method investments): Investments in privately held entities that report NAV 148,627 N/A 148,627 Investments in privately held entities that do not report NAV 265,116 N/A 265,116 Total investments $ 473,483 $ 49,771 $ 523,254 Adjustments recorded on investments in privately held entities that do not report NAV aggregating $10.3 million as of June 30, 2018 , consisted of upward adjustments representing unrealized gains of $10.8 million and downward adjustments representing unrealized losses of $553 thousand . We adjusted our investments in privately held entities that do not report NAV based on observable price changes from subsequent equity offerings. The subsequent equity offerings observed were for similar securities to those we hold as the securities had similar voting rights, distribution preferences, and conversion rights. Investments in privately held entities that report NAV Investments in privately held entities that report NAV consist primarily of investments in limited partnerships. We are committed to funding approximately $190.6 million for all investments over the next several years, primarily consisting of $187.9 million related to investments in limited partnerships. These investments are not redeemable by us, but we normally receive distributions from these investments throughout their term. Our investments in privately held entities that report NAV generally have an expected initial term in excess of 10 years. The weighted-average remaining term during which these investments are expected to be liquidated was 5.4 years as of June 30, 2018 . Our investment income for the three and six months ended June 30, 2018 consisted of the following (in thousands): Three Months Ended June 30, 2018 Unrealized Gains (Losses) Realized Gains Total Investments at fair value, held at period end: Publicly traded companies $ 1,138 $ — $ 1,138 Entities that report NAV 4,683 — 4,683 Entities that do not report NAV with observable price changes since April 1, 2018, held at period end: (754 ) — (754 ) Total investments at fair value, held at period end 5,067 — 5,067 Investment dispositions during the period: Recognized in the current period — 7,463 7,463 Previously recognized as unrealized gains — — — Total investment dispositions during the period — 7,463 7,463 Investment income $ 5,067 $ 7,463 $ 12,530 Six Months Ended June 30, 2018 Unrealized Gains (Losses) Realized Gains Total Investments at fair value, held at period end: Publicly traded companies $ 52,026 $ — $ 52,026 Entities that report NAV 19,770 — 19,770 Entities that do not report NAV with observable price changes since January 1, 2018, held at period end 10,289 — 10,289 Total investments at fair value, held at period end 82,085 — 82,085 Investment dispositions during the period: Recognized in the current period — 16,006 16,006 Previously recognized as unrealized gains (4,789 ) 4,789 — Total investment dispositions during the period (4,789 ) 20,795 16,006 Investment income $ 77,296 $ 20,795 $ 98,091 During the three and six months ended June 30, 2017 , we recognized unrealized losses of $4.0 million and unrealized gains of $6.4 million , respectively, on our equity securities classified as available-for-sale as of June 30, 2017. These unrealized gains/losses were recognized in our consolidated comprehensive income classified within total equity, in accordance with the accounting standards in effect prior to January 1, 2018.

Other assets

Other assets	6 Months Ended
Other assets	Jun. 30, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other assets	Other assets The following table summarizes the components of other assets as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Acquired below-market ground leases $ 17,624 $ 12,684 Acquired in-place leases 134,809 64,979 Deferred compensation plan 19,400 15,534 Deferred financing costs – $1.65 billion unsecured senior line of credit 8,667 10,525 Deposits 5,275 10,576 Furniture, fixtures, and equipment 11,538 11,070 Interest rate hedge assets 5,991 5,260 Net investment in direct financing lease 38,763 38,382 Notes receivable 572 614 Prepaid expenses 13,097 10,972 Property, plant, and equipment 56,841 32,073 Other assets 21,180 15,784 Total $ 333,757 $ 228,453 The components of our net investment in direct financing lease as of June 30, 2018 , and December 31, 2017 , are summarized in the table below (in thousands): June 30, 2018 December 31, 2017 Gross investment in direct financing lease $ 262,918 $ 263,719 Less: unearned income (224,155 ) (225,337 ) Net investment in direct financing lease $ 38,763 $ 38,382 Future minimum lease payments to be received under our direct financing lease as of June 30, 2018 , were as follows (in thousands): Year Total 2018 $ 806 2019 1,655 2020 1,705 2021 1,756 2022 1,809 Thereafter 255,187 Total $ 262,918

Fair value measurements

Fair value measurements	6 Months Ended
Fair value measurements	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements We provide fair value information about all financial instruments 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. 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 six months ended June 30, 2018 . 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 June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 Description Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Investments in publicly traded companies $ 198,616 $ 198,616 $ — $ — Interest rate hedge agreements $ 5,991 $ — $ 5,991 $ — December 31, 2017 Description Total Quoted Prices in Significant Significant Assets: Investments in publicly traded companies $ 109,511 $ 109,511 $ — $ — Interest rate hedge agreements $ 5,260 $ — $ 5,260 $ — Liabilities: Interest rate hedge agreements $ 103 $ — $ 103 $ — Our investments in publicly traded companies have been recognized at fair value. Investments in privately held entities are excluded from the fair value hierarchy above as required by the fair value standards. Refer to Note 6 – “Investments” to these unaudited consolidated financial statements for further details. Our interest rate hedge agreements have been recognized at fair value. Refer to Note 10 – “Interest Rate Hedge Agreements” to these unaudited consolidated financial statements for further details. 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. The fair values of our secured notes payable, unsecured senior notes payable, $1.65 billion unsecured senior line of credit, and unsecured senior bank term loans were estimated using widely accepted valuation techniques, including discounted cash flow analyses using 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 June 30, 2018 , and December 31, 2017 , the book and estimated fair values of our investments in privately held entities that report NAV, secured notes payable, unsecured senior notes payable, unsecured senior line of credit, and unsecured senior bank term loans were as follows (in thousands): June 30, 2018 December 31, 2017 Book Value Fair Value Book Value Fair Value Assets: Investments in privately held entities that report NAV $ 284,656 $ 284,656 N/A N/A Liabilities: Secured notes payable $ 776,260 $ 774,955 $ 771,061 $ 776,222 Unsecured senior notes payable $ 4,289,521 $ 4,300,275 $ 3,395,804 $ 3,529,713 Unsecured senior line of credit $ — $ — $ 50,000 $ 49,986 Unsecured senior bank term loans $ 548,324 $ 550,280 $ 547,942 $ 549,361 Nonrecurring fair value measurements Refer to Note 6 – “Investments” and Note 15 – “Assets Classified as Held for Sale” to these unaudited consolidated financial statements for further discussion.

Secured and unsecured senior de

Secured and unsecured senior debt	6 Months Ended
Secured and unsecured senior debt	Jun. 30, 2018
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 June 30, 2018 (dollars in thousands): Fixed-Rate/Hedged Variable-Rate Debt Unhedged Variable-Rate Debt Weighted-Average Interest Remaining Term (in years) Total Percentage Rate (1) Secured notes payable $ 491,897 $ 284,363 $ 776,260 13.8 % 4.28 % 2.8 Unsecured senior notes payable 4,289,521 — 4,289,521 76.4 4.15 6.9 $1.65 billion unsecured senior line of credit — — — — N/A 3.3 2019 Unsecured Senior Bank Term Loan 199,620 — 199,620 3.6 2.75 0.5 2021 Unsecured Senior Bank Term Loan 348,704 — 348,704 6.2 2.41 2.5 Total/weighted average $ 5,329,742 $ 284,363 $ 5,614,105 100.0 % 4.01 % 5.8 Percentage of total debt 95 % 5 % 100 % (1) Represents the weighted-average interest rate as of the end of the applicable period, including expense/income related to our interest rate hedge agreements, amortization of loan fees, amortization of debt premiums (discounts), and other bank fees. The following table summarizes our outstanding indebtedness and respective principal payments as of June 30, 2018 (dollars in thousands): Stated Rate Interest Rate (1) Maturity Date (2) Unamortized (Deferred Financing Cost), (Discount)/Premium Debt Principal Total Secured notes payable Greater Boston L+1.50 % 3.82 % 1/28/19 (3) $ 334,363 $ (698 ) $ 333,665 Greater Boston, San Diego, Seattle, and Maryland 7.75 % 8.15 4/1/20 107,499 (585 ) 106,914 San Diego 4.66 % 4.90 1/1/23 34,175 (296 ) 33,879 Greater Boston 3.93 % 3.19 3/10/23 81,640 2,566 84,206 Greater Boston 4.82 % 3.40 2/6/24 201,986 14,848 216,834 San Francisco 6.50 % 6.50 7/1/36 762 — 762 Secured debt weighted-average interest rate/subtotal 4.60 % 4.28 760,425 15,835 776,260 2019 Unsecured Senior Bank Term Loan L+1.20 % 2.75 1/3/19 200,000 (380 ) 199,620 2021 Unsecured Senior Bank Term Loan L+1.10 % 2.41 1/15/21 350,000 (1,296 ) 348,704 $1.65 billion unsecured senior line of credit L+1.00 % N/A 10/29/21 — — — Unsecured senior notes payable 2.75 % 2.96 1/15/20 400,000 (1,237 ) 398,763 Unsecured senior notes payable 4.60 % 4.75 4/1/22 550,000 (2,438 ) 547,562 Unsecured senior notes payable 3.90 % 4.04 6/15/23 500,000 (2,945 ) 497,055 Unsecured senior notes payable 4.00 % 4.18 1/15/24 450,000 (4,050 ) 445,950 Unsecured senior notes payable 3.45 % 3.62 4/30/25 600,000 (5,954 ) 594,046 Unsecured senior notes payable 4.30 % 4.50 1/15/26 300,000 (3,648 ) 296,352 Unsecured senior notes payable 3.95 % 4.13 1/15/27 350,000 (4,278 ) 345,722 Unsecured senior notes payable 3.95 % 4.07 1/15/28 425,000 (4,024 ) 420,976 Unsecured senior notes payable 4.50 % 4.60 7/30/29 300,000 (2,452 ) 297,548 Unsecured senior notes payable 4.70 % 4.81 7/1/30 450,000 (4,453 ) 445,547 Unsecured debt weighted average/subtotal 3.96 4,875,000 (37,155 ) 4,837,845 Weighted-average interest rate/total 4.01 % $ 5,635,425 $ (21,320 ) $ 5,614,105 (1) Represents the weighted-average interest rate as of the end of the applicable period, including expense/income related to our interest rate hedge agreements, amortization of loan fees, amortization of debt premiums (discounts), and other bank fees. (2) Reflects any extension options that we control. (3) Secured construction loan for our property at 50 and 60 Binney Street in our Cambridge submarket with aggregate commitments of $350.0 million as of June 30, 2018 . We have two one -year options to extend the stated maturity date to January 28, 2021, subject to certain conditions. In July 2018, we completed a partial repayment of $150.0 million of the outstanding balance and reduced aggregate commitments to $200.0 million . 4.00% and 4.70% Unsecured senior notes payables In June 2018, we completed an offering of $900.0 million of unsecured senior notes for net proceeds of $891.4 million . The offering consisted of $450.0 million of 4.00% unsecured senior notes payable on January 15, 2024 (“4.00% Unsecured Senior Notes”), which will be used to fund certain eligible green development and redevelopment projects that have received or are expected to receive LEED ® Gold or Platinum certification, and $450.0 million of 4.70% unsecured senior notes payable on July 1, 2030 (“4.70% Unsecured Senior Notes”). 3.45% Unsecured senior notes payable due in 2025 In November 2017, we completed a $600.0 million public offering of our unsecured senior notes payable due on April 30, 2025 , at a stated interest rate of 3.45% . We used the net proceeds, after discounts and issuance costs, of $593.5 million to repay two secured notes payable aggregating $389.8 million and for general corporate purposes, including the reduction of the outstanding balance on our $1.65 billion unsecured senior line of credit. 3.95% Unsecured senior notes payable due in 2028 In March 2017, we completed a $425.0 million public offering of our unsecured senior notes payable due on January 15, 2028 , at a stated interest rate of 3.95% . We used the net proceeds, after discounts and issuance costs, of $420.5 million to repay outstanding borrowings under our $1.65 billion unsecured senior line of credit. Repayment of unsecured senior bank term loan During the six months ended June 30, 2017, we completed a partial principal repayment of $200 million of our 2019 Unsecured Senior Bank Term Loan, which reduced the total outstanding balance from $400 million to $200 million , and recognized a loss on early extinguishment of debt of $670 thousand related to the write-off of unamortized loan fees. Repayment of secured construction loan In July 2018, we repaid $150.0 million of the outstanding balance of one secured construction loan and reduced aggregate commitments to $200.0 million . In connection with the partial repayment of the secured construction loan, we recognized a loss on early extinguishment of debt of $299 thousand related to the write-off of unamortized loan fees. Interest expense The following table summarizes interest expense for the three and six months ended June 30, 2018 and 2017 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Gross interest $ 53,624 $ 46,817 $ 103,899 $ 89,765 Capitalized interest (15,527 ) (15,069 ) (28,887 ) (28,233 ) Interest expense $ 38,097 $ 31,748 $ 75,012 $ 61,532

Interest rate hedge agreements

Interest rate hedge agreements	6 Months Ended
Interest rate hedge agreements	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest rate hedge agreements	Interest rate hedge agreements We use interest rate derivatives to hedge the variable cash flows associated with certain of our existing LIBOR-based variable-rate debt, including our $1.65 billion unsecured senior line of credit, unsecured senior bank term loans, and secured notes payable, and to manage our exposure to interest rate volatility. Changes in fair value, including accrued interest and adjustments for non-performance risk, on our interest rate hedge agreements that are designated and that qualify as cash flow hedges are classified in accumulated other comprehensive income. Amounts classified in accumulated other comprehensive income 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 $5.3 million from accumulated other comprehensive income to earnings as a decrease of interest expense. As of June 30, 2018 , and December 31, 2017 , the fair values of our interest rate hedge agreements aggregating an asset balance were classified in other assets, and the fair values of our interest rate hedge agreements aggregating a liability balance were classified in accounts payable, accrued expenses, and tenant security deposits, based upon their respective fair values, without any offsetting pursuant to master netting agreements. Refer to Note 8 – “Fair Value Measurements” to these unaudited consolidated financial statements for further details. Under our interest rate hedge agreements, we have no collateral posting requirements. We have agreements with certain of our derivative counterparties that contain a provision wherein we could be declared in default on our derivative obligations (i) 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 its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender. If we had breached any of these provisions, we could have been required to settle our obligations under the agreements at their termination value. As of June 30, 2018 , none of our interest rate hedge agreements were in a liability position, so there were no associated termination obligations. We had the following outstanding interest rate hedge agreements that were designated as cash flow hedges of interest rate risk as of June 30, 2018 (dollars in thousands): Number of Contracts Weighted-Average Interest Pay Rate (1) Fair Value as of 6/30/18 Notional Amount in Effect as of Effective Date Maturity Date 6/30/18 12/31/18 12/31/19 March 29, 2018 March 31, 2019 8 1.16% $ 5,142 $ 600,000 $ 600,000 $ — March 29, 2019 March 31, 2020 1 1.89% 849 — — 100,000 Total $ 5,991 $ 600,000 $ 600,000 $ 100,000 (1) In addition to the interest pay rate for each swap agreement, interest is payable at an applicable margin over LIBOR for borrowings outstanding as of June 30, 2018 , as listed under the column heading “Stated Rate” in our summary table of outstanding indebtedness and respective principal payments under Note 9 – “Secured and Unsecured Senior Debt” to these unaudited consolidated financial statements.

Accounts payable, accrued expen

Accounts payable, accrued expenses, and tenant security deposits	6 Months Ended
	Jun. 30, 2018
Accounts payable, accrued expenses, and tenant security deposits [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 June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Accounts payable and accrued expenses $ 394,435 $ 349,884 Acquired below-market leases 123,402 88,184 Conditional asset retirement obligations 10,519 7,397 Deferred rent liabilities 28,367 27,953 Interest rate hedge liabilities — 103 Unearned rent and tenant security deposits 248,543 248,924 Other liabilities 44,008 41,387 Total $ 849,274 $ 763,832 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. For certain properties we do not recognize 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.

Earnings per share

Earnings per share	6 Months Ended
Earnings per share	Jun. 30, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Earnings per share	Earnings per share In January 2018, we entered into forward equity sales agreements to sell an aggregate of 6.9 million shares of our common stock (including the exercise of underwriters’ option) at a public offering price of $123.50 per share, before underwriting discounts. In March 2018, we settled 843,600 shares from our forward equity sales agreements and received proceeds of $100.2 million , net of underwriting discounts and adjustments provided in the forward equity sales agreements. We expect to receive additional proceeds of $709.9 million upon settlement of the remaining outstanding forward equity sales agreements, to be further adjusted as provided in the sales agreements. The remaining forward equity sales agreements expire no later than April 2019, and we expect to settle these agreements in 2018. In March 2017, we entered into agreements to sell an aggregate of 6.9 million shares of our common stock, which consisted of an initial issuance of 2.1 million shares and 4.8 million shares subject to forward equity sales agreements, at a public offering price of $108.55 per share less issuance costs, underwriters’ discount, and further adjustments as provided in the sales agreements. We issued the initial 2.1 million shares at closing in March 2017 for net proceeds, after underwriters’ discount and issuance costs, of $217.8 million and settled the forward equity sales agreements on the remaining 4.8 million shares of common stock in December 2017 for net proceeds, after underwriters’ discount and issuance costs, of $484.6 million . To account for the forward equity sales agreements, we considered the accounting guidance governing financial instruments and derivatives and concluded that our forward equity sales agreements were not liabilities as they did not embody obligations to repurchase our shares, nor did they embody obligations to issue a variable number of shares for which the monetary value was predominantly fixed, varying with something other than the fair value of our shares, or varying inversely in relation to our shares. We then evaluated whether the agreements met the derivatives and hedging guidance scope exception to be accounted for as equity instruments and concluded that the agreements can be classified as equity contracts based on the following assessment: (i) none of the agreements’ exercise contingencies were based on observable markets or indices besides those related to the market for our own stock price and operations; and (ii) none of the settlement provisions precluded the agreements from being indexed to our own stock. We also considered the potential dilution resulting from the forward equity sales agreements on the EPS calculations. At inception, the agreements do not have an effect on the computation of basic EPS as no shares are delivered until settlement. We use the treasury stock method to determine the dilution resulting from the forward equity sales agreements during the period of time prior to settlement. The common shares issued upon the settlement of the forward equity sales agreements, weighted for the period these common shares were outstanding, are included in the denominator of basic EPS. The number of weighted-average shares outstanding – diluted used in the computation of EPS for the three and six months ended June 30, 2018 and 2017 , includes the effect from the assumed issuance of common stock pursuant to the settlement of forward equity sales agreements outstanding during the period at the contractual price, less the assumed repurchase of common shares at the average market price using the net proceeds, adjusted as provided in the forward equity sales agreements. The effect on our weighted-average shares – diluted for the three and six months ended June 30, 2018 , was 355 thousand and 313 thousand weighted-average incremental shares, respectively. For the three and six months ended June 30, 2017 , the effect on our weighted-average shares – diluted from the forward equity sales agreements entered into in March 2017 was 530 thousand and 293 thousand weighted-average incremental shares, respectively. The common shares issued upon the partial settlement of the forward equity sales agreements in March 2018 aggregating 843,600 , weighted for the period these common shares were outstanding, were included in the denominator of basic EPS for the three and six months ended June 30, 2018 . For purposes of calculating diluted EPS, we did not assume conversion of our 7.00% Series D cumulative convertible preferred stock (“Series D Convertible Preferred Stock”) for the three and six months ended June 30, 2018 and 2017 , since the result was antidilutive to EPS attributable to Alexandria Real Estate Equities, Inc.’s common stockholders from continuing operations during those periods. Refer to Note 13 – “Stockholders’ Equity” to these unaudited consolidated financial statements for further discussion of the partial repurchases of our Series D Convertible Preferred Stock. 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 and forward equity sales agreements are not participating securities and therefore are not included in the computation of EPS using the two-class method. Under the two-class method, we allocate net income (after amounts attributable to noncontrolling interests, dividends on preferred stock, and preferred stock redemption charge) to common stockholders and unvested restricted stock awards by using the weighted-average shares of each class outstanding for quarter-to-date and year-to-date periods independently, based on their respective participation rights to dividends declared (or accumulated) and undistributed earnings. The table below is a reconciliation of the numerators and denominators of the basic and diluted EPS computations for the three and six months ended June 30, 2018 and 2017 (in thousands, except per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Net income $ 60,547 $ 41,496 $ 202,065 $ 89,051 Net income attributable to noncontrolling interests (5,817 ) (7,275 ) (11,705 ) (13,119 ) Dividends on preferred stock (1,302 ) (1,278 ) (2,604 ) (5,062 ) Preferred stock redemption charge — — — (11,279 ) Net income attributable to unvested restricted stock awards (1,412 ) (1,313 ) (2,765 ) (2,300 ) Numerator for basic and diluted EPS – net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders $ 52,016 $ 31,630 $ 184,991 $ 57,291 Denominator for basic EPS – weighted-average shares of common stock outstanding 101,881 90,215 100,878 89,186 Dilutive effect of forward equity sales agreements 355 530 313 293 Denominator for diluted EPS – weighted-average shares of common stock outstanding 102,236 90,745 101,191 89,479 Net income per share attributable to Alexandria Real Estate Equities, Inc.’s common stockholders: Basic $ 0.51 $ 0.35 $ 1.83 $ 0.64 Diluted $ 0.51 $ 0.35 $ 1.83 $ 0.64

Stockholders' equity

Stockholders' equity	6 Months Ended
Stockholders' equity	Jun. 30, 2018
Stockholders' Equity Note [Abstract]
Stockholders' equity	Stockholders’ equity ATM common stock offering program In August 2017, we established an ATM common stock offering program that allows us to sell up to an aggregate of $750.0 million of our common stock. As of December 31, 2017, we sold an aggregate of 2.8 million shares of common stock under this program for gross proceeds of $336.6 million . During the three and six months ended June 30, 2018 , we sold additional 2.5 million shares of common stock under our ATM common stock offering program for gross proceeds of $305.7 million , or $124.46 per share, and received net proceeds of $300.8 million . As of June 30, 2018 , we sold an aggregate of 5.2 million shares of common stock under this program for gross proceeds of $642.3 million , or $122.82 per share, and received net proceeds of $632.0 million . As of June 30, 2018 , the remaining aggregate amount available under our current program for future sales of common stock was $107.7 million . In July 2018, we sold 703,625 shares of common stock under our ATM common stock offering program for gross proceeds of $90.0 million , or $127.91 per share, and received net proceeds of $88.7 million . As of July 30, 2018 , the remaining aggregate amount available under our current program for future sales of common stock was $17.7 million . Forward equity sales agreements Refer to Note 12 – “Earnings per Share” to these unaudited consolidated financial statements for a discussion related to our forward equity sales agreements executed in January 2018 and March 2017. 7.00% Series D cumulative convertible preferred stock repurchases As of June 30, 2018 and 2017, we had 3.0 million shares of our Series D Convertible Preferred Stock outstanding. During the six months ended June 30, 2017 , we repurchased, in privately negotiated transactions, 501,115 outstanding shares of our Series D Convertible Preferred Stock at an aggregate price of $17.9 million , or $35.79 per share. We recognized a preferred stock redemption charge of $5.8 million during the six months ended June 30, 2017 , including the write-off of original issuance costs of approximately $391 thousand . 6.45% Series E cumulative redeemable preferred stock redemption In March 2017, we announced the redemption of our 6.45% Series E cumulative redeemable preferred stock (“Series E Redeemable Preferred Stock”) and recognized a preferred stock redemption charge of $5.5 million related to the write-off of original issuance costs. On April 14, 2017 , we completed the redemption of all 5.2 million outstanding shares of our Series E Redeemable Preferred Stock at a redemption price of $25.00 per share, or an aggregate of $130.0 million , plus accrued dividends, using funds primarily from the proceeds of our March 2017 common stock offering. Dividends In June 2018 , we declared cash dividends on our common stock for the three months ended June 30, 2018 , aggregating $97.6 million , or $0.93 per share. Also in June 2018 , we declared cash dividends on our Series D Convertible Preferred Stock for the three months ended June 30, 2018 , aggregating approximately $1.3 million , or $0.4375 per share. In July 2018, we paid the cash dividends on our common stock and Series D Convertible Preferred Stock declared for the three months ended June 30, 2018 . For the six months ended June 30, 2018 , our declared cash dividends on our common stock aggregated $189.6 million , or $1.83 per share, and our declared cash dividends on our Series D Convertible Preferred Stock aggregated $2.6 million , or $0.875 per share. Accumulated other comprehensive income Accumulated other comprehensive income attributable to Alexandria Real Estate Equities, Inc. consists of the following (in thousands): Net Unrealized Gain (Loss) on: Available-for- Sale Equity Securities Interest Rate Foreign Currency Translation Total Balance as of December 31, 2017 $ 49,771 $ 5,157 $ (4,904 ) $ 50,024 Amounts reclassified from other comprehensive income to retained earnings (49,771 ) (1) — — (49,771 ) Other comprehensive income (loss) before reclassifications — 2,643 (3,572 ) (929 ) Amounts reclassified from other comprehensive income to net income — (1,809 ) — (1,809 ) Net other comprehensive income — 834 (3,572 ) (2,738 ) Balance as of June 30, 2018 $ — $ 5,991 $ (8,476 ) $ (2,485 ) (1) Refer to Note 6 – “Investments” to these unaudited consolidated financial statements for additional information. Common stock, preferred stock, and excess stock authorizations Our charter authorizes the issuance of 200.0 million shares of common stock, of which 103.3 million shares were issued and outstanding as of June 30, 2018 . Our charter also authorizes the issuance of up to 100.0 million shares of preferred stock, of which 3.0 million shares were issued and outstanding as of June 30, 2018 . 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 June 30, 2018 .

Noncontrolling interests

Noncontrolling interests	6 Months Ended
Noncontrolling interests	Jun. 30, 2018
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 eight properties as of June 30, 2018 , and are included in our unaudited 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. During the six months ended June 30, 2018 and 2017 , our consolidated joint ventures distributed $18.4 million and $10.8 million , respectively, to our joint venture partners. We sold partial interests in 10290 Campus Point Drive and 10300 Campus Point Drive in 2016, and 9625 Towne Centre Drive in 2017. We retained controlling interests in both joint ventures following the sales and continued to consolidate these entities; therefore, we accounted for the proceeds received as equity financing transactions. These transactions did not qualify as sales of real estate and did not result in purchase accounting adjustments to the carrying value. Accordingly, the carrying amounts of our partner’s share of assets and liabilities are reported at historical cost basis. 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 unaudited 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. 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.

Assets classified as held for s

Assets classified as held for sale	6 Months Ended
Assets classified as held for sale	Jun. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Assets classified as held for sale	Assets classified as held for sale As of June 30, 2018 , two buildings aggregating 389,018 RSF and one land parcel were classified as held for sale, none of which met the criteria for classification as discontinued operations in our consolidated financial statements. The land parcel was sold in July 2018. Refer to Note 3 – “Investments in Real Estate” to these unaudited consolidated financial statements for additional information. The following is a summary of net assets as of June 30, 2018 , and December 31, 2017 , for our real estate investments that were classified as held for sale in each respective period (in thousands): June 30, 2018 December 31, 2017 Total assets $ 41,934 $ 31,578 Total liabilities (1,789 ) (1,809 ) Total accumulated other comprehensive income (436 ) (1,021 ) Net assets classified as held for sale $ 39,709 $ 28,748

Condensed consolidating financi

Condensed consolidating financial information	6 Months Ended
Condensed consolidating financial information	Jun. 30, 2018
Condensed Consolidated Financial Information [Abstract]
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 of 1933, as amended, that are fully and unconditionally guaranteed by Alexandria Real Estate Equities, L.P. (the “LP” or the “Guarantor Subsidiary”), an indirectly 100% owned subsidiary of the Issuer. The Issuer’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 June 30, 2018 , and December 31, 2017 , the condensed consolidating statements of income and comprehensive income for the three and six months ended June 30, 2018 and 2017 , and the condensed consolidating statements of cash flows for the six months ended June 30, 2018 and 2017 , for the Issuer, the Guarantor Subsidiary, and the Combined Non-Guarantor Subsidiaries, as well as the eliminations necessary to arrive at the information on a consolidated basis. 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 June 30, 2018 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Assets Investments in real estate $ — $ — $ 11,190,771 $ — $ 11,190,771 Investments in unconsolidated real estate JVs — — 192,972 — 192,972 Cash and cash equivalents 181,342 — 105,687 — 287,029 Restricted cash 155 — 34,657 — 34,812 Tenant receivables — — 8,704 — 8,704 Deferred rent — — 490,428 — 490,428 Deferred leasing costs — — 232,964 — 232,964 Investments — 1,690 789,063 — 790,753 Investments in and advances to affiliates 11,253,161 10,066,773 205,029 (21,524,963 ) — Other assets 51,551 — 282,206 — 333,757 Total assets $ 11,486,209 $ 10,068,463 $ 13,532,481 $ (21,524,963 ) $ 13,562,190 Liabilities, Noncontrolling Interests, and Equity Secured notes payable $ — $ — $ 776,260 $ — $ 776,260 Unsecured senior notes payable 4,289,521 — — — 4,289,521 Unsecured senior line of credit — — — — — Unsecured senior bank term loans 548,324 — — — 548,324 Accounts payable, accrued expenses, and tenant security deposits 89,227 — 760,047 — 849,274 Dividends payable 98,676 — — — 98,676 Total liabilities 5,025,748 — 1,536,307 — 6,562,055 Redeemable noncontrolling interests — — 10,861 — 10,861 Alexandria Real Estate Equities, Inc.’s stockholders’ equity 6,460,461 10,068,463 11,456,500 (21,524,963 ) 6,460,461 Noncontrolling interests — — 528,813 — 528,813 Total equity 6,460,461 10,068,463 11,985,313 (21,524,963 ) 6,989,274 Total liabilities, noncontrolling interests, and equity $ 11,486,209 $ 10,068,463 $ 13,532,481 $ (21,524,963 ) $ 13,562,190 Condensed Consolidating Balance Sheet as of December 31, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Assets Investments in real estate $ — $ — $ 10,298,019 $ — $ 10,298,019 Investments in unconsolidated real estate JVs — — 110,618 — 110,618 Cash and cash equivalents 130,364 9 124,008 — 254,381 Restricted cash 152 — 22,653 — 22,805 Tenant receivables — — 10,262 — 10,262 Deferred rent — — 434,731 — 434,731 Deferred leasing costs — — 221,430 — 221,430 Investments — 1,655 521,599 — 523,254 Investments in and advances to affiliates 9,949,861 9,030,994 183,850 (19,164,705 ) — Other assets 45,108 — 183,345 — 228,453 Total assets $ 10,125,485 $ 9,032,658 $ 12,110,515 $ (19,164,705 ) $ 12,103,953 Liabilities, Noncontrolling Interests, and Equity Secured notes payable $ — $ — $ 771,061 $ — $ 771,061 Unsecured senior notes payable 3,395,804 — — — 3,395,804 Unsecured senior line of credit 50,000 — — — 50,000 Unsecured senior bank term loans 547,942 — — — 547,942 Accounts payable, accrued expenses, and tenant security deposits 89,928 — 673,904 — 763,832 Dividends payable 92,145 — — — 92,145 Total liabilities 4,175,819 — 1,444,965 — 5,620,784 Redeemable noncontrolling interests — — 11,509 — 11,509 Alexandria Real Estate Equities, Inc.’s stockholders’ equity 5,949,666 9,032,658 10,132,047 (19,164,705 ) 5,949,666 Noncontrolling interests — — 521,994 — 521,994 Total equity 5,949,666 9,032,658 10,654,041 (19,164,705 ) 6,471,660 Total liabilities, noncontrolling interests, and equity $ 10,125,485 $ 9,032,658 $ 12,110,515 $ (19,164,705 ) $ 12,103,953 Condensed Consolidating Statement of Income for the Three Months Ended June 30, 2018 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Revenues: Rental $ — $ — $ 250,635 $ — $ 250,635 Tenant recoveries — — 72,159 — 72,159 Other income 4,965 — 3,112 (5,837 ) 2,240 Total revenues 4,965 — 325,906 (5,837 ) 325,034 Expenses: Rental operations — — 91,908 — 91,908 General and administrative 23,001 — 5,775 (5,837 ) 22,939 Interest 32,139 — 5,958 — 38,097 Depreciation and amortization 1,647 — 117,205 — 118,852 Impairment on real estate — — 6,311 — 6,311 Total expenses 56,787 — 227,157 (5,837 ) 278,107 Equity in earnings of unconsolidated real estate JVs — — 1,090 — 1,090 Equity in earnings of affiliates 106,552 98,795 1,943 (207,290 ) — Investment (loss) income — (97 ) 12,627 — 12,530 Net income 54,730 98,698 114,409 (207,290 ) 60,547 Net income attributable to noncontrolling interests — — (5,817 ) — (5,817 ) Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders 54,730 98,698 108,592 (207,290 ) 54,730 Dividends on preferred stock (1,302 ) — — — (1,302 ) Net income attributable to unvested restricted stock awards (1,412 ) — — — (1,412 ) Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders $ 52,016 $ 98,698 $ 108,592 $ (207,290 ) $ 52,016 Condensed Consolidating Statement of Income for the Three Months Ended June 30, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Revenues: Rental $ — $ — $ 211,942 $ — $ 211,942 Tenant recoveries — — 60,470 — 60,470 Other income 4,124 1 1,482 (4,960 ) 647 Total revenues 4,124 1 273,894 (4,960 ) 273,059 Expenses: Rental operations — — 76,980 — 76,980 General and administrative 19,428 — 4,766 (4,960 ) 19,234 Interest 21,831 — 9,917 — 31,748 Depreciation and amortization 1,721 — 102,377 — 104,098 Impairment of real estate — — 203 — 203 Total expenses 42,980 — 194,243 (4,960 ) 232,263 Equity in earnings of unconsolidated real estate JVs — — 589 — 589 Equity in earnings of affiliates 73,077 70,597 1,360 (145,034 ) — Gain on sales of real estate – land parcels — — 111 — 111 Net income 34,221 70,598 81,711 (145,034 ) 41,496 Net income attributable to noncontrolling interests — — (7,275 ) — (7,275 ) Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders 34,221 70,598 74,436 (145,034 ) 34,221 Dividends on preferred stock (1,278 ) — — — (1,278 ) Net income attributable to unvested restricted stock awards (1,313 ) — — — (1,313 ) Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders $ 31,630 $ 70,598 $ 74,436 $ (145,034 ) $ 31,630 Condensed Consolidating Statement of Comprehensive Income for the Three Months Ended June 30, 2018 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Net income $ 54,730 $ 98,698 $ 114,409 $ (207,290 ) $ 60,547 Other comprehensive (loss) income Unrealized losses on interest rate hedge agreements: Unrealized interest rate hedge gains arising during the period 661 — — — 661 Reclassification adjustment for amortization of interest income included in net income (1,131 ) — — — (1,131 ) Unrealized losses on interest rate hedge agreements, net (470 ) — — — (470 ) Unrealized losses on foreign currency translation: Unrealized foreign currency translation losses arising during the period — — (3,243 ) — (3,243 ) Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation — — — — — Unrealized losses on foreign currency translation, net — — (3,243 ) — (3,243 ) Total other comprehensive loss (470 ) — (3,243 ) — (3,713 ) Comprehensive income 54,260 98,698 111,166 (207,290 ) 56,834 Less: comprehensive income attributable to noncontrolling interests — — (5,817 ) — (5,817 ) Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders $ 54,260 $ 98,698 $ 105,349 $ (207,290 ) $ 51,017 Condensed Consolidating Statement of Comprehensive Income for the Three Months Ended June 30, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Net income $ 34,221 $ 70,598 $ 81,711 $ (145,034 ) $ 41,496 Other comprehensive income Unrealized losses on available-for-sale equity securities: Unrealized holding losses arising during the period — (1 ) (4,024 ) — (4,025 ) Reclassification adjustment for losses included in net income — 1 2,348 — 2,349 Unrealized losses on available-for-sale equity securities, net — — (1,676 ) — (1,676 ) Unrealized gains (losses) on interest rate hedge agreements: Unrealized interest rate hedge losses arising during the period (411 ) — (139 ) — (550 ) Reclassification adjustment for amortization of interest expense included in net income 705 — 2 — 707 Unrealized gains (losses) on interest rate hedge agreements, net 294 — (137 ) — 157 Unrealized gains on foreign currency translation: Unrealized foreign currency translation gains arising during the period — — 2,744 — 2,744 Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation — — — — — Unrealized gains on foreign currency translation, net — — 2,744 — 2,744 Total other comprehensive income 294 — 931 — 1,225 Comprehensive income 34,515 70,598 82,642 (145,034 ) 42,721 Less: comprehensive income attributable to noncontrolling interests — — (7,283 ) — (7,283 ) Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders $ 34,515 $ 70,598 $ 75,359 $ (145,034 ) $ 35,438 Condensed Consolidating Statement of Cash Flows for the Six Months Ended June 30, 2018 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non-Guarantor Subsidiaries Eliminations Consolidated Operating Activities Net income $ 190,360 $ 198,053 $ 307,946 $ (494,294 ) $ 202,065 Adjustments to reconcile net income to net cash (used in) provided by operating activities: Depreciation and amortization 3,324 — 229,747 — 233,071 Impairment of real estate — — 6,311 — 6,311 Equity in earnings of unconsolidated real estate JVs — — (2,234 ) — (2,234 ) Distributions of earnings from unconsolidated real estate JVs — — 287 — 287 Amortization of loan fees 4,260 — 876 — 5,136 Amortization of debt discounts (premiums) 378 — (1,559 ) — (1,181 ) Amortization of acquired below-market leases — — (11,368 ) — (11,368 ) Deferred rent — — (55,890 ) — (55,890 ) Stock compensation expense 15,223 — — — 15,223 Equity in earnings of affiliates (292,720 ) (197,677 ) (3,897 ) 494,294 — Investment income 43 (375 ) (97,759 ) — (98,091 ) Changes in operating assets and liabilities: Tenant receivables — — 1,552 — 1,552 Deferred leasing costs — — (29,705 ) — (29,705 ) Other assets (10,894 ) — (4,161 ) — (15,055 ) Accounts payable, accrued expenses, and tenant security deposits (726 ) (2 ) 8,848 — 8,120 Net cash (used in) provided by operating activities (90,752 ) (1 ) 348,994 — 258,241 Investing Activities Additions to real estate — — (431,225 ) — (431,225 ) Purchases of real estate — — (688,698 ) — (688,698 ) Deposits for investing activities — — 5,500 — 5,500 Investments in subsidiaries (1,010,580 ) (838,102 ) (17,282 ) 1,865,964 — Acquisitions of interests in unconsolidated real estate JVs — — (35,922 ) — (35,922 ) Investments in unconsolidated real estate JVs — — (44,486 ) — (44,486 ) Additions to investments — — (118,775 ) — (118,775 ) Sales of investments — 377 44,330 — 44,707 Net cash used in investing activities $ (1,010,580 ) $ (837,725 ) $ (1,286,558 ) $ 1,865,964 $ (1,268,899 ) Condensed Consolidating Statement of Cash Flows (continued) for the Six Months Ended June 30, 2018 (In thousands) (Unaudited) Alexandria Real Alexandria Real Combined Eliminations Consolidated Financing Activities Borrowings from secured notes payable $ — $ — $ 9,044 $ — $ 9,044 Repayments of borrowings from secured notes payable — — (3,162 ) — (3,162 ) Proceeds from issuance of unsecured senior notes payable 899,321 — — — 899,321 Borrowings from unsecured senior line of credit 2,469,000 — — — 2,469,000 Repayments of borrowings from unsecured senior line of credit (2,519,000 ) — — — (2,519,000 ) Transfers to/from parent company 96,432 837,717 931,815 (1,865,964 ) — Payment of loan fees (8,003 ) — — — (8,003 ) Proceeds from the issuance of common stock 400,207 — — — 400,207 Dividends on common stock (183,040 ) — — — (183,040 ) Dividends on preferred stock (2,604 ) — — — (2,604 ) Contributions from noncontrolling interests — — 14,564 — 14,564 Distributions to and purchases of noncontrolling interests — — (19,841 ) — (19,841 ) Net cash provided by financing activities 1,152,313 837,717 932,420 (1,865,964 ) 1,056,486 Effect of foreign exchange rate changes on cash and cash equivalents — — (1,173 ) — (1,173 ) Net increase (decrease) in cash, cash equivalents, and restricted cash 50,981 (9 ) (6,317 ) — 44,655 Cash, cash equivalents, and restricted cash as of the beginning of period 130,516 9 146,661 — 277,186 Cash, cash equivalents, and restricted cash as of the end of period $ 181,497 $ — $ 140,344 $ — $ 321,841 Supplemental Disclosure of Cash Flow Information: Cash paid during the period for interest, net of interest capitalized $ 56,392 $ — $ 12,493 $ — $ 68,885 Non-Cash Investing Activities: Change in accrued construction $ — $ — $ 48,074 $ — $ 48,074 Condensed Consolidating Statement of Cash Flows for the Six Months Ended June 30, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non-Guarantor Subsidiaries Eliminations Consolidated Operating Activities Net income $ 75,932 $ 153,457 $ 175,647 $ (315,985 ) $ 89,051 Adjustments to reconcile net income to net cash (used in) provided by operating activities: Depreciation and amortization 3,430 — 197,851 — 201,281 Loss on early extinguishment of debt 670 — — — 670 Gain on sales of real estate – rental properties — — (270 ) — (270 ) Impairment of real estate — — 203 — 203 Gain on sales of real estate – land parcels — — (111 ) — (111 ) Equity in losses of unconsolidated real estate JVs — — (950 ) — (950 ) Distributions of earnings from unconsolidated real estate JVs — — 249 — 249 Amortization of loan fees 3,774 — 1,964 — 5,738 Amortization of debt discounts (premiums) 290 — (1,511 ) — (1,221 ) Amortization of acquired below-market leases — — (10,363 ) — (10,363 ) Deferred rent — — (53,497 ) — (53,497 ) Stock compensation expense 10,756 — — — 10,756 Equity in earnings of affiliates (159,548 ) (153,445 ) (2,992 ) 315,985 — Investment income — (5 ) (957 ) — (962 ) Changes in operating assets and liabilities: Tenant receivables — — 1,354 — 1,354 Deferred leasing costs — — (26,811 ) — (26,811 ) Other assets (8,947 ) — 4,293 — (4,654 ) Accounts payable, accrued expenses, and tenant security deposits (7,109 ) (12 ) 20,404 — 13,283 Net cash (used in) provided by operating activities (80,752 ) (5 ) 304,503 — 223,746 Investing Activities Proceeds from sales of real estate — — 3,528 — 3,528 Additions to real estate — — (436,377 ) — (436,377 ) Purchases of real estate — — (480,543 ) — (480,543 ) Deposits for investing activities — — 450 — 450 Investments in subsidiaries (573,334 ) (464,024 ) (9,565 ) 1,046,923 — Investments in unconsolidated real estate JVs — — (163 ) — (163 ) Additions to investments — — (81,192 ) — (81,192 ) Sales of investments — 204 12,373 — 12,577 Net cash used in investing activities $ (573,334 ) $ (463,820 ) $ (991,489 ) $ 1,046,923 $ (981,720 ) Condensed Consolidating Statement of Cash Flows (continued) for the Six Months Ended June 30, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non-Guarantor Subsidiaries Eliminations Consolidated Financing Activities Borrowings from secured notes payable $ — $ — $ 117,666 $ — $ 117,666 Repayments of borrowings from secured notes payable — — (1,677 ) — (1,677 ) Proceeds from issuance of unsecured senior notes payable 424,384 — — — 424,384 Borrowings from unsecured senior line of credit 2,069,000 — — — 2,069,000 Repayments of borrowings from unsecured senior line of credit (1,797,000 ) — — — (1,797,000 ) Repayments of borrowings from unsecured bank term loans (200,000 ) — — — (200,000 ) Transfers to/from parent company 21,995 463,825 561,103 (1,046,923 ) — Payment of loan fees (3,957 ) — (387 ) — (4,344 ) Repurchase of 7.00% Series D cumulative convertible preferred stock (17,934 ) — — — (17,934 ) Redemption of 6.45% Series E cumulative redeemable preferred stock (130,350 ) — — — (130,350 ) Proceeds from the issuance of common stock 459,607 — — — 459,607 Dividends on common stock (149,296 ) — — — (149,296 ) Dividends on preferred stock (7,015 ) — — — (7,015 ) Contributions from noncontrolling interests — — 8,505 — 8,505 Distributions to and purchases of noncontrolling interests — — (10,791 ) — (10,791 ) Net cash provided by financing activities 669,434 463,825 674,419 (1,046,923 ) 760,755 Effect of foreign exchange rate changes on cash and cash equivalents — — 732 — 732 Net increase (decrease) in cash, cash equivalents, and restricted cash 15,348 — (11,835 ) — 3,513 Cash, cash equivalents, and restricted cash as of the beginning of period 30,705 — 110,661 — 141,366 Cash, cash equivalents, and restricted cash as of the end of period $ 46,053 $ — $ 98,826 $ — $ 144,879 Supplemental Disclosure of Cash Flow Information: Cash paid during the period for interest, net of interest capitalized $ 41,598 $ — $ 12,212 $ — $ 53,810 Non-Cash Investing Activities: Change in accrued construction $ — $ — $ (25,138 ) $ — $ (25,138 ) Contribution of real estate to an unconsolidated real estate JV $ — $ — $ 6,998 $ — $ 6,998

Summary of significant accoun23

Summary of significant accounting policies (Policies)	6 Months Ended
Summary of significant accounting policies (Policies)	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation	Consolidation On an ongoing basis, as circumstances indicate the need for reconsideration, we evaluate each legal entity that is not wholly owned by us in accordance with the consolidation guidance. Our evaluation considers all of our variable interests, including equity ownership, as well as fees paid to us for our involvement in the management of each partially owned entity. To fall within the scope of the consolidation guidance, an entity must meet both of the following criteria: • The entity has a legal structure that has been established to conduct business activities and to hold assets; such entity can be in the form of a partnership, limited liability company, or corporation, among others; and • We have a variable interest in the legal entity – i.e., variable interests that are contractual, such as equity ownership, or other financial interests that change with changes in the fair value of the entity’s net assets. If an entity does not meet both criteria above, we apply other accounting literature, such as the cost or equity method of accounting. If an entity does meet both criteria above, we evaluate such entity for consolidation under either the variable interest model if the legal entity meets any of the following characteristics to qualify as a VIE, or under the voting model for all other legal entities that are not VIEs. A legal entity is determined to be a VIE if it has any of the following three characteristics: 1) The entity does not have sufficient equity to finance its activities without additional subordinated financial support; 2) The entity is established with non-substantive voting rights (i.e., where the entity deprives the majority economic interest holder(s) of voting rights); or 3) The equity holders, as a group, lack the characteristics of a controlling financial interest. Equity holders meet this criterion if they lack any of the following: • The power, through voting rights or similar rights, to direct the activities of the entity that most significantly influence the entity’s economic performance, as evidenced by: • Substantive participating rights in day-to-day management of the entity’s activities; or • Substantive kick-out rights over the party responsible for significant decisions; • The obligation to absorb the entity’s expected losses; or • The right to receive the entity’s expected residual returns. Once we consider the sufficiency of equity and voting rights of each legal entity, we then evaluate the characteristics of the equity holders’ interests, as a group, to see if they qualify as controlling financial interests. Our real estate joint ventures consist of limited partnerships or limited liability companies. For an entity structured as a limited partnership or a limited liability company, our evaluation of whether the equity holders (equity partners other than us in each of our joint ventures) lack the characteristics of a controlling financial interest includes the evaluation of whether the limited partners or non-managing members (the noncontrolling equity holders) lack both substantive participating rights and substantive kick-out rights, defined as follows: • Participating rights provide the noncontrolling equity holders the ability to direct significant financial and operating decisions made in the ordinary course of business that most significantly influence the entity’s economic performance. • Kick-out rights allow the noncontrolling equity holders to remove the general partner or managing member without cause. If we conclude that any of the three characteristics of a VIE are met, including that the equity holders lack the characteristics of a controlling financial interest because they lack both substantive participating rights and substantive kick-out rights, we conclude that the entity is a VIE and evaluate it for consolidation under the variable interest model. Variable interest model If an entity is determined to be a VIE, we evaluate whether we are the primary beneficiary. The primary beneficiary analysis is a qualitative analysis based on power and benefits. We consolidate a VIE if we have both power and benefits – that is, (i) we have the power to direct the activities of a VIE that most significantly influence the VIE’s economic performance (power), and (ii) we have the obligation to absorb losses of or the right to receive benefits from the VIE that could potentially be significant to the VIE (benefits). We consolidate VIEs whenever we determine that we are the primary beneficiary. Refer to Note 4 – “Consolidated and Unconsolidated Real Estate Joint Ventures” to these unaudited consolidated financial statements for information on specific joint ventures that qualify as VIEs. If we have a variable interest in a VIE but we are not the primary beneficiary, we account for our investment using the equity method of accounting. Voting model If a legal entity fails to meet any of the three characteristics of a VIE (due to insufficiency of equity, existence of non-substantive voting rights, or lack of a controlling financial interest), we then evaluate such entity under the voting model. Under the voting model, we consolidate the entity if we determine that we, directly or indirectly, have greater than 50% of the voting shares and that other equity holders do not have substantive participating rights. Refer to Note 4 – “Consolidated and Unconsolidated Real Estate Joint Ventures” to these unaudited consolidated financial statements for further information on our unconsolidated real estate joint ventures that qualify for evaluation under the voting model.
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.
Investments in real estate and properties classified as held for sale	Investments in real estate Evaluation of business combination or asset acquisition We evaluate each acquisition of real estate or in-substance real estate (including equity interests in entities that predominantly hold real estate assets) to determine whether the integrated set of assets and activities acquired meets the definition of a business and needs to be accounted as a business combination. An acquisition of an integrated set of assets and activities that does not meet the definition of a business is accounted for as an asset acquisition. If either of the following criteria is met, the integrated set of assets and activities acquired would not qualify as a business: • Substantially all of the fair value of the gross assets acquired is concentrated in either a single identifiable asset or a group of similar identifiable assets; or • The integrated set of assets and activities is lacking, at a minimum, an input and a substantive process that together significantly contribute to the ability to create outputs (i.e., revenue generated before and after the transaction). An acquired process is considered substantive if: • The process includes an organized workforce (or includes an acquired contract that provides access to an organized workforce) that is skilled, knowledgeable, and experienced in performing the process; • The process cannot be replaced without significant cost, effort, or delay; or • The process is considered unique or scarce. Generally, we expect that acquisitions of real estate or in-substance real estate will not meet the definition of a business because substantially all of the fair value is concentrated in a single identifiable asset or group of similar identifiable assets (i.e., land, buildings, and related intangible assets) or because the acquisition does not include a substantive process in the form of an acquired workforce or an acquired contract that cannot be replaced without significant cost, effort, or delay. When evaluating acquired service or management contracts, we consider the nature of the services performed, the terms of the contract relative to similar arm’s-length contracts, and the availability of comparable vendors in evaluating whether the acquired contract constitutes a substantive process. Recognition of real estate acquired For acquisitions of real estate or in-substance real estate that are accounted for as business combinations, we recognize the assets acquired (including the intangible value of acquired above- or below-market leases, acquired in-place leases, tenant relationships, and other intangible assets or liabilities), liabilities assumed, noncontrolling interests, and previously existing ownership interests at fair value as of the acquisition date. Any excess (deficit) of the consideration transferred relative to the fair value of the net assets acquired is accounted for as goodwill (bargain purchase gain). Acquisition costs related to business combinations are expensed as incurred. Acquisitions of real estate and in-substance real estate that do not meet the definition of a business are accounted for as asset acquisitions. The accounting model for asset acquisitions is similar to the accounting model for business combinations except that the acquisition consideration (including acquisition costs) is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis. As a result, asset acquisitions do not result in the recognition of goodwill or a bargain purchase gain. Additionally, because the accounting model for asset acquisitions is a cost accumulation model, preexisting interests in the acquired assets, if any, are not remeasured to fair value but continue to be accounted for at their historical cost. Direct acquisition costs are capitalized if an asset acquisition is probable. If we determine that an asset acquisition is no longer probable, no new costs are capitalized and all capitalized costs that are not recoverable are expensed. The relative fair values used to allocate the cost of an asset acquisition are determined by the same methodologies and assumptions we utilize to determine fair value in a business combination. If a real estate property is acquired with an in-place lease that contains a bargain fixed-rate renewal option for the period beyond the non-cancelable lease term, 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 its space 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 renewal option will be exercised, we consider the option 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 under the 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. 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 up to 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 increases (for below-market leases) or decreases (for above-market leases) to rental revenue. The values of acquired above- and below-market ground leases are amortized over the terms of the related ground leases and recognized as either increases (for below-market ground leases) or decreases (for above-market ground leases) to rental operating expense. 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. Capitalized project costs We capitalize project costs, including pre-construction costs, interest, property taxes, insurance, and other costs directly related and essential to the development, redevelopment, pre-construction, or construction of a project. Capitalization of development, redevelopment, pre-construction, and construction costs is required while activities are ongoing to prepare an asset for its intended use. Fluctuations in our development, redevelopment, pre-construction, 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, pre-construction, 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. Real estate sales 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. If the disposal of a 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, 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 will typically not meet the criteria for classification as a discontinued operation.
Impairment of long-lived assets	Impairment of long-lived assets 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, if necessary, a probability-weighted approach if multiple outcomes are under consideration. 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 carrying amount of a long-lived asset may not be recoverable. The carrying 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, land held for development, and intangibles, are assessed by project and include significant fluctuations in estimated net operating income, 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 carrying 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.
International operations	International operations In addition to operating properties in the U.S., we have three operating properties in Canada and one operating property in China. The functional currency for our subsidiaries operating in the U.S. is the U.S. dollar. 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 weighted-average exchange rate for the periods presented. Gains or losses resulting from the translation are classified in accumulated other comprehensive income as a separate component of total equity. Whenever a foreign investment meets the criteria for classification as held for sale, we evaluate the recoverability of the investment under the held for sale impairment model. We may recognize an impairment charge if the carrying amount of the investment exceeds its fair value less cost to sell. In determining an investment’s carrying amount, we consider its net book value and any cumulative unrealized foreign currency translation adjustment related to the investment. The appropriate amounts of foreign exchange rate gains or losses classified in accumulated other comprehensive income are reclassified to net income when realized upon the sale of our investment or upon the complete or substantially complete liquidation of our investment.
Investments	Investments We hold investments in publicly traded companies and privately held entities primarily involved in the life science and technology industries. As a REIT, we generally limit our ownership percentage in the voting stock of each individual entity to less than 10% . Prior to January 1, 2018 Prior to the adoption of a new ASU on financial instruments effective January 1, 2018, all of our equity investments in actively traded public companies were considered available-for-sale and were presented in the accompanying consolidated balance sheets at fair value. Fair value was determined based upon the closing price as of each balance sheet date, with unrealized gains and losses shown as a separate component of accumulated other comprehensive income within total equity (excluded from net income). The classification of each investment was determined at the time each investment was made, and such determination was reevaluated at each balance sheet date. The cost of each investment sold was 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 were generally accounted for under the cost method when our interest in the entity was so minor that we had virtually no influence over the entity’s operating and financial policies. Investments in privately held entities were accounted for under the equity method unless our interest in the entity was deemed to be so minor that we had virtually no influence over the entity’s operating and financial policies. Under the equity method of accounting, we recognized our investment initially at cost and adjusted the carrying amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment. We periodically assessed our investments in available-for-sale equity securities and privately held companies accounted for under the cost method for other-than-temporary impairment. We monitored each of our investments throughout the year for new developments, including operating results, results of clinical trials, capital-raising events, and merger and acquisition activities. Individual investments were evaluated for impairment when changes in conditions indicated an impairment may exist. The factors that we considered in making these assessments included, but were 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 an unrealized loss related to an available-for-sale equity security was determined to be other-than-temporary, such unrealized loss was reclassified from accumulated other comprehensive income within total equity into earnings. For a cost method investment, if a decline in the fair value of an investment below its carrying value was determined to be other-than-temporary, such investment was written down to its estimated fair value with a charge to earnings. If there were no identified events or changes in circumstances that might have had an adverse effect on our cost method investments, we did not estimate the investment’s fair value. Effective January 1, 2018 Beginning on January 1, 2018, under the new ASU, equity investments (except those accounted for under the equity method and those that result in consolidation of the investee) are measured at fair value, with changes in fair value recognized in net income, as follows: • Investments in publicly traded companies are classified as investments with readily determinable fair values. These investments are carried at fair value, with changes in fair value recognized in net income, rather than in accumulated other comprehensive income within total equity. The fair values for our investments in publicly traded companies continue to be determined based on sales prices/quotes available on securities exchanges, or published prices that serve as the basis for current transactions. • Investments in privately held entities without readily determinable fair values fall into two categories: • Investments in privately held entities that report net asset value per share (“NAV”), such as our privately held investments in limited partnerships, are carried at fair value using NAV as a practical expedient with changes in fair value recognized in net income. • Investments in privately held entities that do not report NAV are accounted for using a measurement alternative which allows these investments to be measured at cost, adjusted for observable price changes and impairments, with changes recognized in net income. For investments in privately held entities that do not report NAV, an observable price is a price observed in an orderly transaction for an identical or similar investment of the same issuer. Observable price changes result from, among other things, equity transactions for the same issuer executed during the reporting period, including subsequent equity offerings or other reported equity transactions related to the same issuer. For these transactions to be considered observable price changes, we evaluate whether these transactions have similar rights and obligations, including voting rights, distribution preferences, conversion rights, and other factors, to the investments we hold. Investments in privately held entities that do not report NAV continue to be evaluated on the basis of a qualitative assessment for indicators of impairment by utilizing the same monitoring criteria described above. If such indicators are present, we are required to estimate the investment’s fair value and immediately recognize an impairment loss, without consideration as to whether the impairment is other-than-temporary, in an amount equal to the investment’s carrying value in excess of its estimated fair value. Investments in privately held entities continue to be 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 initially recognize our investment at cost and adjust the carrying amount of the investment to recognize our share of the earnings or losses of the investee subsequent to the date of our investment. Initial adoption of new ASU On January 1, 2018, we recognized the following adjustments upon adoption of the new ASU: • For investments in publicly traded companies, reclassification of cumulative unrealized gains as of December 31, 2017, aggregating $49.8 million , from accumulated other comprehensive income to retained earnings. • For investments in privately held entities without readily determinable fair values that were previously accounted for under the cost method: • Adjustment to investments for unrealized gains aggregating $90.8 million related to investments in privately held entities that report NAV, representing the difference between fair value as of December 31, 2017, using NAV as a practical expedient and the carrying value of the investments as of December 31, 2017, with a corresponding adjustment to retained earnings. • No adjustment was required for investments in privately held entities that do not report NAV. The ASU requires a prospective transition approach for investments in privately held entities that do not report NAV. The FASB clarified that it would be difficult for entities to determine the last observable transaction price existing prior to the adoption of this ASU. Therefore, unlike our investments in privately held entities that report NAV that were adjusted to reflect fair values upon adoption of the new ASU, our investments in privately held entities that do not report NAV were not retrospectively adjusted to fair values upon adoption. As such, any initial valuation adjustments made for investments in privately held entities that do not report NAV subsequent to January 1, 2018, as a result of future observable price changes include recognition of unrealized gains or losses equal to the difference between the carrying basis of the investment and the observable price at the date of remeasurement.
Revenue recognition	Revenue recognition Recognition of revenue arising from contracts with customers On January 1, 2018, we adopted an ASU on revenue recognition that requires a new model for recognition of revenue arising from contracts with customers, as well as recognition of gains and losses from the transfer of nonfinancial assets arising from contracts with noncustomers. A customer is distinguished from a noncustomer by the nature of the goods or services that are transferred. Customers are provided with goods or services that are generated by a company’s ordinary output activities, whereas noncustomers are provided with nonfinancial assets that are outside of a company’s ordinary output activities. The core principle underlying the ASU on recognition of revenue arising from contracts with customers is that an entity must recognize revenue to represent the transfer of goods and services to customers in an amount that reflects the consideration to which the entity expects to be entitled in such exchange. This requires entities to identify contractual performance obligations and determine whether revenue should be recognized at a point in time or over time, based on when control of goods and services transfers to a customer. The ASU requires the use of a new five-step model to recognize revenue from customer contracts. The five-step model requires that we (i) identify the contract with the customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, including variable consideration to the extent that it is probable that a significant future reversal will not occur, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) we satisfy the performance obligation. An entity is also required to determine if it controls the goods or services prior to the transfer to the customer in order to determine if it should account for the arrangement as a principal or agent. Principal arrangements, where the entity controls the goods or services provided, result in the recognition of the gross amount of consideration expected in the exchange. Agent arrangements, where the entity simply arranges but does not control the goods or services being transferred to the customer, result in the recognition of the net amount the entity is entitled to retain in the exchange. Upon adoption of the new lease ASU in 2019, we will be required to classify our tenant recoveries into lease and nonlease components, whereby the nonlease components would be subject to the ASU on recognition of revenue arising from contracts with customers. However, if we elect a practical expedient, as discussed in “Lessor Accounting” within the “Lease Accounting” section of “Recent Accounting Pronouncements” contained in Note 2, tenant recoveries for goods and services that are categorized as nonlease components but have the same timing and pattern of transfer as the related lease component may (subject to the predominance test) be accounted for under the new lease ASU. Tenant recoveries that do not qualify for the practical expedient will be accounted for under the ASU on recognition of revenue arising from contracts with customers upon adoption of the new lease ASU. Property services categorized as nonlease components that are reimbursed by our tenants may need to be presented on a net basis if it is determined that we hold an agent arrangement. Entities had the option to transition to the ASU on recognition of revenue arising from contracts with customers using either the full retrospective or the modified retrospective method. We adopted this ASU using the modified retrospective method, which requires a cumulative adjustment for effects of applying the new standard to periods prior to 2018 to be recorded to retained earnings as of January 1, 2018. We also elected to apply this ASU only to contracts not completed as of January 1, 2018. For all contracts within the scope of this ASU that were not completed as of January 1, 2018, we evaluated the revenue recognition under accounting standards in effect prior to January 1, 2018, and under the new ASU, and determined that amounts recognized and the pattern of revenue recognition were consistent. Therefore, the adoption of the ASU on recognition of revenue arising from contracts with customers did not result in an adjustment to our retained earnings on January 1, 2018. The table below provides the detail of our consolidated revenues for the three and six months ended June 30, 2018 , by (i) revenues that are subject to the ASU on recognition of revenue arising from contracts with customers, and (ii) revenues subject to other accounting standards (in thousands): Three months ended June 30, 2018 Six Months Ended June 30, 2018 Subject to the ASU on Recognition of Revenue from Contracts with Customers Subject to Other Accounting Guidance Total Subject to the ASU on Recognition of Revenue from Contracts with Customers Subject to Other Accounting Guidance Total Rental $ 12,086 $ 238,549 $ 250,635 $ 22,519 $ 472,601 $ 495,120 Tenant recoveries — 72,159 72,159 — 145,329 145,329 Other income 1,496 744 2,240 3,516 1,208 4,724 Total revenues $ 13,582 $ 311,452 $ 325,034 $ 26,035 $ 619,138 $ 645,173 Rental revenues, subject to the new revenue recognition ASU, aggregating $12.1 million and $22.5 million for the three and six months ended June 30, 2018 , respectively, consist primarily of parking revenues. Parking revenues consist primarily of short term rental revenues that are not considered lease revenue. Under the previous accounting standards, we recognized parking and other revenue when the amounts were fixed or determinable, collectibility was reasonably assured, and services were rendered. Under the new ASU, the recognition of such revenue occurs when the services are provided and the performance obligations are satisfied. Parking services are normally provided at a point in time; therefore, revenue recognition under the new ASU is substantially similar to the recognition pattern under accounting standards that were in effect prior to January 1, 2018. Other income, subject to the new revenue recognition ASU, aggregating $1.5 million and $3.5 million for the three and six months ended June 30, 2018 , respectively, consists primarily of construction management fees. We earn construction management fees for the day-to-day management of third-party construction projects. Construction management services represent a series of services that are substantially the same and that can be combined into a single performance obligation. Under the previous accounting guidance, we recognized construction management fees using the percentage of completion method. Under the new ASU, we recognize construction management fees using the output method, which is substantially similar to the percentage of completion method used under the guidance in effect prior to January 1, 2018. In addition to the analysis above, we evaluated the following qualitative and quantitative disclosure requirements outlined in this ASU during the six months ended June 30, 2018 , as follows: • Prior to the adoption of this ASU, we did not have material contract assets and contract liabilities related to contracts with customers subject to the new revenue recognition ASU, and no additional contract assets or contract liabilities were necessary subsequent to adoption on January 1, 2018. • Parking and construction management services subject to the new revenue recognition ASU do not normally create obligations for returns, refunds, warranties, and other similar obligations. Therefore, no corresponding disclosures were necessary.
Recognition of rental income and tenant recoveries	Recognition of rental income and tenant recoveries Rental revenue from operating leases is recognized on a straight-line basis over the respective lease terms. We classify amounts currently recognized as rental revenue in our consolidated statements of income, and amounts expected to be received in later years as deferred rent in the accompanying consolidated balance sheets. Amounts received currently but recognized as revenue 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 revenue at the date the property is ready for its intended use and the tenant takes possession of or controls the physical use of the property. Rental revenue from direct financing leases is recognized over the respective lease terms using the effective interest rate method. At lease inception, we record an asset within other assets in our consolidated balance sheets, which represents our net investment in the direct financing lease. This initial net investment is determined by aggregating the total future minimum lease payments attributable to the direct financing lease and the estimated residual value of the property less unearned income. Over the lease term, the investment in the direct financing lease is reduced and rental income is recognized as rental revenue in our consolidated statements of income and produces a constant periodic rate of return on the net investment in the direct financing lease. 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 and the tenant’s obligation to reimburse us arises. Tenant receivables consist primarily of amounts due for contractual lease payments and tenant recoveries. These 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 tenants to make payments required under the terms of the lease and for tenant recoveries due. If a 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 tenant receivables and deferred rent arising from the straight-lining of rent. As of June 30, 2018 , and December 31, 2017 , no allowance for uncollectible tenant receivables and deferred rent was deemed necessary.
Monitoring tenant credit quality	Monitoring tenant credit quality During the term of each lease, we monitor the credit quality and any related material changes of our tenants by (i) monitoring the credit rating of tenants that are rated by a nationally recognized credit rating agency, (ii) reviewing financial statements of the 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 tenants and their respective businesses, and (iv) monitoring the timeliness of lease payments.
Income taxes	Income taxes We are organized and operate as a REIT pursuant to the Internal Revenue Code (the “Code”). Under the Code, a REIT that distributes at least 90% of its REIT taxable income to its stockholders annually (excluding net capital gains) and meets certain other conditions is not subject to federal income tax on its distributed taxable income, but could be subject to certain federal, foreign, 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, foreign, 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 routine examination in various jurisdictions for the 2012 through 2017 calendar years. On December 22, 2017, the U.S. President signed a tax reform bill commonly referred to as the Tax Cuts and Jobs Act into law. The tax reform legislation is a far-reaching and complex revision to the U.S. federal income tax laws with disparate and, in some cases, countervailing effects on different categories of taxpayers and industries. The legislation is unclear in many respects and will require clarification and interpretation by the U.S. Treasury Department and the Internal Revenue Service (“IRS”) in the form of amendments, technical corrections, regulations, or other forms of guidance, any of which could lessen or increase the effect of the legislation on us or our stockholders. The outcome of this legislation on state and local tax authorities, and the response by such authorities, is also unclear. We will continue to monitor changes made to, or as a result of, the federal tax law and its potential effect on us.
Employee share-based payments	Employee share-based payments We account for forfeitures of share-based awards granted to employees when they occur. This entity-wide accounting policy election only applies to service conditions; for performance conditions, we continue to assess the probability that such conditions will be achieved. As a result of this election, we recognize expense on share-based awards with time-based vesting conditions without reductions for an estimate of forfeitures. Expenses related to forfeited awards are reversed as forfeitures occur. In addition, all nonforfeitable dividends paid on share-based payment awards are initially recognized in retained earnings and reclassified to compensation cost only if forfeitures of the underlying awards occur.
Recent accounting pronouncements	Recent accounting pronouncements Lease accounting Overview related to both lessee and lessor accounting In February 2016, the FASB issued an ASU that sets out the principles for the recognition, measurement, presentation, and disclosure of leases for both parties to a lease agreement (i.e., lessees and lessors). The ASU is effective for us no later than January 1, 2019, with early adoption permitted. We expect to adopt the new lease accounting standard on January 1, 2019. The ASU requires us to identify lease and nonlease components of a lease agreement. This ASU will govern the recognition of revenue for lease components. Revenue related to nonlease components under our lease agreements will be subject to the new revenue recognition ASU, effective upon adoption of the new lease accounting standard. However, in July 2018, the FASB issued an ASU to modify the application of this ASU by lessors to lease and nonlease components within lease agreements. See further discussion related to this update and other proposed changes in the “Lessor Accounting” section below. The lease ASU sets new criteria for determining the classification of finance leases for lessees and sales-type leases for lessors. The criteria to determine if a lease should be accounted for as a finance (sales-type) lease include the following: (i) ownership is transferred from lessor to lessee by the end of the lease term, (ii) an option to purchase is reasonably certain to be exercised, (iii) the lease term is for the major part of the underlying asset’s remaining economic life, (iv) the present value of lease payments exceeds substantially all of the fair value of the underlying asset, and (v) the underlying asset is specialized and is expected to have no alternative use at the end of the lease term. If any of these criteria is met, a lease will be classified as a finance lease by the lessee and as a sales-type lease by the lessor. If none of the criteria are met, a lease will be classified as an operating lease by the lessee, but may still qualify as a direct financing lease or an operating lease for the lessor. The existence of a residual value guarantee from an unrelated third party other than the lessee may qualify the lease as a direct financing lease by the lessor. Otherwise, the lease will be classified as an operating lease by both the lessee and lessor. The lease ASU requires the use of the modified retrospective transition method and does not allow for a full retrospective approach. However, it provides two options for the application of the modified retrospective transition method: • Under the first option, this ASU requires application of the standard to all leases that exist as of, or commence after, January 1, 2017 (the beginning of the earliest comparative period presented in the 2019 financial statements), with a cumulative adjustment to the opening balance of retained earnings on January 1, 2017, for the effect of applying the standard at the date of initial application, and restatement of the amounts presented prior to January 1, 2019. • Under the second option, an entity may elect a practical expedient package, which allows for the following: • An entity need not reassess whether any expired or existing contracts are or contain leases; • An entity need not reassess the lease classification for any expired or existing leases; and • An entity need not reassess initial direct costs for any existing leases. This practical expedient package is available as a single election that must be consistently applied to all existing leases at the date of adoption. Lessors that adopt this package are not expected to reassess expired or existing leases at the date of initial application, which is January 1, 2017, under the ASU. This option enables entities to “run off” their existing leases for the remainder of the respective lease terms, which eliminates the need to calculate a cumulative adjustment to the opening balance of retained earnings. Furthermore, in July 2018, the FASB issued an ASU that provides an optional transition method to make the initial application date of the ASU January 1, 2019, rather than January 1, 2017. Consequently, entities that elect both the practical expedient package and the optional transition method will apply the new lease ASU prospectively to leases commencing or modified after January 1, 2019, and will not be required to apply the disclosures under the new lease ASU to comparative periods. Under either option above, lessees will be required to recognize a right-of-use asset and a lease liability for all operating leases on the date of the initial application based on the present value of the remaining minimum rental payments that were tracked and disclosed under current accounting standards. The FASB has also clarified that the lease ASU will require an assessment of whether a land easement meets the definition of a lease under the new lease ASU. An entity with existing land easements that are not accounted for as leases under the current lease accounting standards, however, may elect a practical expedient to exclude those land easements from assessment under the new lease accounting standards. The new lease ASU will be applied to all land easement arrangements entered into or modified on and after the ASU effective date; however, it is expected to have little or no effect on land easements that contain minimal or no consideration. Lessor accounting We recognized revenue from our lease agreements aggregating $617.9 million for the six months ended June 30, 2018 . This revenue consisted primarily of rental revenues and tenant recoveries for the six months ended June 30, 2018 , aggregating $472.6 million and $145.3 million , respectively. Under current lease accounting standards, we recognize rental revenue from our operating leases on a straight-line basis over the respective lease terms. We commence recognition of rental revenue at the date the property is ready for its intended use and the tenant takes possession of, or controls the physical use of, the property. We recognize rental revenue from direct financing leases over the lease term by using the effective interest rate method. Under current lease accounting standards, tenant recoveries related to payments of real estate taxes, insurance, utilities, repairs and maintenance, common area expenses, and other operating expenses are considered lease components. We recognize these tenant recoveries as revenue when services are rendered in an amount equal to the related operating expenses incurred that are recoverable under the terms of the applicable lease. Under the new lease ASU, each lease agreement will be evaluated to identify the lease components and nonlease components at lease inception. The total consideration in the lease agreement will be allocated to the lease and nonlease components based on their relative stand-alone selling prices. The new ASU will govern the recognition of revenue for lease components. Revenue related to nonlease components will be subject to the new revenue recognition ASU, effective upon adoption of the new lease accounting standard. Lessors will continue to recognize the lease revenue component using an approach that is substantially equivalent to existing guidance for operating leases (straight-line basis). Sales-type and direct financing leases will be accounted for as financing transactions, with the lease payments allocated to principal and interest by utilizing the effective interest rate method. Under the new lease ASU, tenant recoveries for utilities, repairs and maintenance, and common area expenses are expected to primarily be categorized as nonlease components. Tenant recoveries for taxes and insurance are expected to be neither lease nor nonlease components under the lease ASU but instead will be considered additional lease revenue to be recognized by the lessor. In July 2018, the FASB issued an ASU that allows lessors to elect, as a practical expedient, not to allocate the total consideration to the lease and nonlease components based on their relative stand-alone selling prices. If adopted, this single-lease component practical expedient will allow lessors to elect a combined single-lease component presentation if (i) the timing and pattern of transfer of the lease component and the nonlease component(s) associated with it are the same, and (ii) the lease component would be classified as an operating lease if it were accounted for separately. Nonlease components that do not meet the criteria of this practical expedient will be accounted for under the new revenue recognition ASU. The FASB also decided to require lessors to account for a combined component that meets these two criteria under the new revenue recognition ASU if the nonlease component is the predominant component. If the nonlease component is not the predominant component, entities will be able to account for the combined component as an operating lease in accordance with the new lease ASU. Based on our preliminary analysis, we expect that most of our leases for which we are the lessor will qualify for the single-lease component presentation as operating leases. If we elect the single-lease component practical expedient described above, tenant recoveries that qualify for this expedient will be accounted for as a single-lease component under the new lease ASU, primarily as variable consideration. Tenant recoveries that do not qualify for the single-lease component practical expedient and are considered nonlease components will be accounted for under the new revenue recognition ASU upon adoption of the new lease ASU. The new lease ASU also requires a lessor to recognize lessor’s costs (i.e., real estate taxes and insurance) paid directly by a lessee to a third party on a gross basis as lease revenue and lease expense. However, in March 2018, the FASB made a tentative decision to amend the ASU to allow a lessor not to estimate lessor costs paid by the lessee directly to a third party when the lessor cannot determine the amount of those costs. In these cases, lessors will not recognize these costs in their income statements. This ASU has not been issued as of the date of this report. Costs to execute leases The new lease ASU will require that lessors and lessees capitalize, as initial direct costs, only those costs that are incurred due to the execution of a lease (i.e., commissions paid to leasing brokers). Under this ASU, allocated payroll costs, legal costs, and other out-of-pocket costs incurred as part of the leasing process prior to the execution of a lease will no longer qualify for classification as initial direct costs and will instead be expensed as incurred. We will have the option, under the practical expedient package provided by the new lease ASU, to continue to amortize previously capitalized initial direct costs incurred prior to the adoption of the ASU. During the six months ended June 30, 2018 , we completed 76 leases aggregating approximately 2.5 million rentable square feet with a weighted average lease term of 10.4 years . These leases generally represent mission-critical office/laboratory space with high barriers to exit for our tenants. As a result, approximately 51% of these leases were negotiated directly with our tenants and did not require payment of third-party commissions to leasing brokers. Our total initial direct leasing costs (leasing commissions, payroll, and legal fees) for the six months ended June 30, 2018 aggregated $33.3 million , or approximately $1.30 per rentable square foot leased per year of lease term. Included in the $33.3 million for the six months ended June 30, 2018 was $9.2 million of allocated payroll and legal costs, or approximately $0.36 per rentable square foot leased per year of lease term, related to these leases, which, if incurred under the new lease ASU, would have been expensed. Lessee accounting Under the new lease ASU, lessees are required to apply a dual approach by classifying leases as either finance or operating leases based on the principle of whether the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease, which corresponds to a similar evaluation performed by lessors. In addition to this classification, a lessee is also required to recognize a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification, whereas a lessor is not required to recognize a right-of-use asset and a lease liability for any operating leases. Leases with a lease term of 12 months or less will be accounted for in a manner similar to existing guidance for operating leases (i.e., straight-line basis). The new lease ASU requires the recognition of a right-of-use asset and a related liability to account for our future obligations under our ground and office lease agreements for which we are the lessee. At the date of initial application, depending on the practical expedients we elect as discussed above, we will be required to recognize a lease liability measured based on the present value of the remaining lease payments. The present value of the remaining lease payments will be calculated using the incremental borrowing rate, which is the interest rate that we estimate we would have to pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments. The right-of-use asset will be equal to the corresponding lease liability, adjusted for the initial direct leasing cost and any other consideration exchanged with the landlord prior to the commencement of the lease. As of June 30, 2018 , the remaining contractual payments under our ground and office lease agreements for which we are the lessee aggregated $610.8 million , and the estimated present value of these payments is in the range from $200.0 million to $230.0 million . This estimated present value range is based on a weighted average remaining lease term of 47 years and our estimated weighted average incremental borrowing rate in the range from 5% to 6% . Incremental borrowing rate is the interest rate that we estimate we would have to pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments. The actual lease liability and right-of-use asset to be recognized upon adoption of the new lease ASU will vary depending on changes to our incremental borrowing rate and the practical expedients we elect as discussed above. All of our existing ground and office leases for which we are the lessee are currently classified as operating leases. Under the practical expedient package provided by the lease ASU, we will have the option to continue to classify these leases as operating leases upon adoption of the lease ASU. We are still evaluating the effect on our consolidated financial statements of the initial recognition of each lease asset and liability upon adoption, and the pattern of recognition of ground lease expense subsequent to adoption. Allowance for credit losses In June 2016, the FASB issued an ASU that changes the impairment model for most financial instruments by requiring companies to recognize an allowance for expected losses, rather than incurred losses as required currently by the other-than-temporary impairment model. The ASU will apply to most financial assets measured at amortized cost and certain other instruments, including trade and other receivables, loans, held-to-maturity debt securities, net investments in leases, and off-balance-sheet credit exposures (i.e., loan commitments). The ASU is effective for reporting periods beginning after December 15, 2019, with early adoption permitted, and will be applied as a cumulative adjustment to retained earnings as of the effective date. We are currently assessing the potential effect the adoption of this ASU will have on our consolidated financial statements. Joint venture distributions On January 1, 2018, we adopted an ASU that provides guidance on the classification in the statement of cash flows of cash distributions received from equity method investments, including unconsolidated joint ventures. The ASU provides two approaches to determine the classification of cash distributions received from equity method investees: (i) the “cumulative earnings” approach, under which distributions up to the amount of cumulative equity in earnings recognized are classified as cash inflows from operating activities, and those in excess of that amount are classified as cash inflows from investing activities, and (ii) the “nature of the distribution” approach, under which distributions are classified based on the nature of the underlying activity that generated cash distributions. An entity could elect either the “cumulative earnings” or the “nature of the distribution” approach. If the “nature of the distribution” approach is elected and the entity lacks the information necessary to apply it in the future, that entity will have to apply the “cumulative earnings” approach as an accounting change on a retrospective basis. We adopted this ASU using the “nature of the distribution” approach and applied it retrospectively, as required by the ASU. We previously presented distributions from our equity method investees utilizing the “nature of the distribution” approach; therefore, the adoption of this ASU had no effect on our consolidated financial statements. Restricted cash On January 1, 2018, we adopted an ASU that requires entities to include restricted cash with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown in the statement of cash flows. The ASU requires disclosure of a reconciliation between the balance sheet and the statement of cash flows when the balance sheet includes more than one line item for cash, cash equivalents, restricted cash, and restricted cash equivalents. An entity with material restricted cash and restricted cash equivalents balances is required to disclose the nature of the restrictions. The ASU required a retrospective application to all periods presented. Subsequent to the adoption of this ASU, restricted cash balances are included with cash and cash equivalents balances as of the beginning and ending of each period presented in our consolidated statements of cash flows; separate line items reconciling changes in restricted cash balances to the changes in cash and cash equivalents are no longer presented within the operating, investing, and financing sections of our consolidated statements of cash flows. Hedge accounting On January 1, 2018, we adopted an ASU that simplifies hedge accounting. The ASU is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The purpose of this updated ASU is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. For cash flow hedges that are highly effective, the new standard requires all changes (effective and ineffective components) in the fair value of the hedging instrument to be recorded in accumulated other comprehensive income within total equity and to be reclassified into earnings only when the hedged item affects earnings. Prior to the adoption of this ASU, a quantitative assessment was made on an ongoing basis to determine whether a hedge is highly effective in offsetting changes in cash flows associated with the hedged item. Previously applied hedge accounting guidance required hedge ineffectiveness to be recognized in earnings. Under the new ASU, an entity is still required to perform an initial quantitative test. However, the new standard allows an entity to elect to subsequently perform only a qualitative assessment, unless facts and circumstances change. We made this election upon adoption of the new ASU on January 1, 2018. We utilize interest rate hedge agreements to hedge a portion of our exposure to variable interest rates primarily associated with borrowings based on LIBOR. As a result, all of our interest rate hedge agreements are designated as cash flow hedges. For cash flow hedges in existence at the date of adoption, an entity is required to apply a cumulative-effect adjustment for previously recognized ineffectiveness from retained earnings to accumulated other comprehensive income as of the beginning of the fiscal year when an entity adopts the amendments in this ASU. We performed an analysis of all our cash flow hedges existing on January 1, 2018, and determined that all hedges had been highly effective since their inception; therefore, no cumulative-effect adjustment of previously recognized ineffectiveness from retained earnings to accumulated other comprehensive income was needed. The adoption of this ASU had no effect on our financial statements.

Summary of significant accoun24

Summary of significant accounting policies (Tables)	6 Months Ended
Summary of significant accounting policies (Tables)	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenues subject to new revenue recognition adoption	The table below provides the detail of our consolidated revenues for the three and six months ended June 30, 2018 , by (i) revenues that are subject to the ASU on recognition of revenue arising from contracts with customers, and (ii) revenues subject to other accounting standards (in thousands): Three months ended June 30, 2018 Six Months Ended June 30, 2018 Subject to the ASU on Recognition of Revenue from Contracts with Customers Subject to Other Accounting Guidance Total Subject to the ASU on Recognition of Revenue from Contracts with Customers Subject to Other Accounting Guidance Total Rental $ 12,086 $ 238,549 $ 250,635 $ 22,519 $ 472,601 $ 495,120 Tenant recoveries — 72,159 72,159 — 145,329 145,329 Other income 1,496 744 2,240 3,516 1,208 4,724 Total revenues $ 13,582 $ 311,452 $ 325,034 $ 26,035 $ 619,138 $ 645,173

Investments in real estate (Tab

Investments in real estate (Tables)	6 Months Ended
Investments in real estate (Tables)	Jun. 30, 2018
Real Estate [Abstract]
Summary of investments in real estate	Our consolidated investments in real estate consisted of the following as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Land (related to rental properties) $ 1,442,071 $ 1,312,072 Buildings and building improvements 9,559,442 9,000,626 Other improvements 880,549 780,117 Rental properties 11,882,062 11,092,815 Development and redevelopment of new Class A properties: Development and redevelopment projects (under construction, marketing, or pre-construction) 1,253,419 955,218 Future development projects 92,473 96,112 Gross investments in real estate 13,227,954 12,144,145 Less: accumulated depreciation (2,066,333 ) (1,875,810 ) Net investments in real estate – North America 11,161,621 10,268,335 Net investments in real estate – Asia 29,150 29,684 Investments in real estate $ 11,190,771 $ 10,298,019
Real estate assets acquisitions	Our real estate asset acquisitions during the six months ended June 30, 2018 and subsequently, consisted of the following (dollars in thousands): Square Footage Three Months Ended Operating Operating with Active or Future Redevelopment Active or Future Purchase Price March 31, 2018 487,227 106,733 643,765 $ 339,400 June 30, 2018 782,388 39,505 793,000 405,855 Subsequent acquisitions 45,626 349,947 217,000 257,000 1,315,241 496,185 1,653,765 $ 1,002,255

Consolidated and unconsolidat26

Consolidated and unconsolidated real estate joint ventures (Tables)	6 Months Ended
	Jun. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Consolidated and unconsolidated real estate joint venture properties	From time to time, we enter into joint venture agreements through which we own a partial interest in real estate entities that own, develop, and operate real estate properties. As of June 30, 2018 , we had the following properties that were held by our real estate joint ventures: Property (1) Market Submarket Our Ownership Interest RSF Consolidated joint ventures: 225 Binney Street Greater Boston Cambridge 30.0 % 305,212 409 and 499 Illinois Street San Francisco Mission Bay/SoMa 60.0 % 455,069 1500 Owens Street San Francisco Mission Bay/SoMa 50.1 % 158,267 Campus Pointe by Alexandria San Diego University Town Center 55.0 % 798,799 9625 Towne Centre Drive San Diego University Town Center 50.1 % 163,648 Unconsolidated joint ventures: Menlo Gateway San Francisco Greater Stanford 29.4 % 772,983 1401/1413 Research Boulevard Maryland Rockville 65.0 % (2) (3) 360 Longwood Avenue Greater Boston Longwood Medical Area 27.5 % 210,709 704 Quince Orchard Road Maryland Gaithersburg 56.8 % (2) 79,931 1655 and 1725 Third Street San Francisco Mission Bay/SoMa 10.0 % 593,765 (1) In addition to the real estate joint ventures listed, various partners hold insignificant noncontrolling interests in four other properties in North America. (2) Represents our ownership interest; our voting interest is limited to 50%. (3) Joint venture with a distinguished retail real estate developer for the development of a 90,000 RSF retail shopping center.
Consolidated VIE's balance sheet information	The table below aggregates the balance sheet information of our consolidated VIEs as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Investments in real estate $ 1,097,759 $ 1,047,472 Cash and cash equivalents 40,352 41,112 Other assets 70,595 68,754 Total assets $ 1,208,706 $ 1,157,338 Secured notes payable $ — $ — Other liabilities 69,191 52,201 Total liabilities 69,191 52,201 Redeemable noncontrolling interests 749 — Alexandria Real Estate Equities, Inc.’s share of equity 610,996 584,160 Noncontrolling interests’ share of equity 527,770 520,977 Total liabilities and equity $ 1,208,706 $ 1,157,338
Investment in unconsolidated real estate joint ventures	As of June 30, 2018 , our investments in unconsolidated real estate joint ventures accounted for under the equity method of accounting presented in our consolidated balance sheet consist of the following (in thousands): Property June 30, 2018 Menlo Gateway $ 121,785 1401/1413 Research Boulevard 7,533 360 Longwood Avenue 25,538 704 Quince Orchard Road 4,384 1655 and 1725 Third Street 33,732 $ 192,972
Summary of secured construction loans	As of June 30, 2018 , our unconsolidated real estate joint ventures have the following non-recourse secured loans that include the following key terms (dollars in thousands): Maturity Date Stated Interest Rate (1) Interest Rate (1)(2) 100% at Joint Venture Level Unconsolidated Joint Venture Our Share Debt Balance (3) Remaining Commitments Menlo Gateway, Phase I 29.4% 3/1/19 L+2.50% 4.49% $ 134,564 $ 13,290 1401/1413 Research Boulevard 65.0% 5/17/20 L+2.50% 5.39% 14,682 9,892 1655 and 1725 Third Street 10.0% 6/29/21 L+3.70% 5.68% 75,520 299,480 360 Longwood Avenue 27.5% 9/1/22 3.32% 3.54% 94,143 17,000 (4) 704 Quince Orchard Road 56.8% 3/16/23 L+1.95% 4.29% 1,016 13,809 Menlo Gateway, Phase II 29.4% 5/1/35 4.53% 4.56% — 157,270 $ 319,925 $ 510,741 (1) For acquired loans, interest rate includes adjustments to reflect the joint venture’s effective borrowing costs at the time of acquisition. (2) Includes interest expense, amortization of loan fees, and amortization of premiums (discounts) as of June 30, 2018 . (3) Represents outstanding principal, net of unamortized deferred financing costs and discount/premium. (4) The remaining loan commitment balance excludes an earn-out advance provision that allows for incremental borrowings up to $48.0 million , subject to certain condition

Cash, cash equivalents, and r27

Cash, cash equivalents, and restricted cash (Tables)	6 Months Ended
Cash, cash equivalents, and restricted cash (Tables)	Jun. 30, 2018
Cash, cash equivalents, and restricted cash [Abstract]
Schedule of Restricted Cash and Cash Equivalents	Cash, cash equivalents, and restricted cash consisted of the following as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Cash and cash equivalents $ 287,029 $ 254,381 Restricted cash: Funds held in trust under the terms of certain secured notes payable 14,384 12,301 Funds held in escrow related to construction projects and investing activities 16,551 4,546 Other 3,877 5,958 34,812 22,805 Total $ 321,841 $ 277,186

Investments (Tables)

Investments (Tables)	6 Months Ended
Investments (Tables)	Jun. 30, 2018
Investments [Abstract]
Summary of investments	The following tables summarize our investments as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 Cost Adjustments Carrying Amount Investments at fair value: Publicly traded companies $ 101,603 $ 97,013 $ 198,616 Entities that report NAV 173,813 110,843 284,656 Entities that do not report NAV: Entities with observable price changes since January 1, 2018 12,811 10,289 23,100 Entities without observable price changes 284,381 — 284,381 Total investments $ 572,608 $ 218,145 $ 790,753 December 31, 2017 Cost Adjustments Total Investments in publicly traded companies $ 59,740 $ 49,771 $ 109,511 Investments in privately held entities without readily determinable fair values (cost method investments): Investments in privately held entities that report NAV 148,627 N/A 148,627 Investments in privately held entities that do not report NAV 265,116 N/A 265,116 Total investments $ 473,483 $ 49,771 $ 523,254
Schedule of net investment income	Our investment income for the three and six months ended June 30, 2018 consisted of the following (in thousands): Three Months Ended June 30, 2018 Unrealized Gains (Losses) Realized Gains Total Investments at fair value, held at period end: Publicly traded companies $ 1,138 $ — $ 1,138 Entities that report NAV 4,683 — 4,683 Entities that do not report NAV with observable price changes since April 1, 2018, held at period end: (754 ) — (754 ) Total investments at fair value, held at period end 5,067 — 5,067 Investment dispositions during the period: Recognized in the current period — 7,463 7,463 Previously recognized as unrealized gains — — — Total investment dispositions during the period — 7,463 7,463 Investment income $ 5,067 $ 7,463 $ 12,530 Six Months Ended June 30, 2018 Unrealized Gains (Losses) Realized Gains Total Investments at fair value, held at period end: Publicly traded companies $ 52,026 $ — $ 52,026 Entities that report NAV 19,770 — 19,770 Entities that do not report NAV with observable price changes since January 1, 2018, held at period end 10,289 — 10,289 Total investments at fair value, held at period end 82,085 — 82,085 Investment dispositions during the period: Recognized in the current period — 16,006 16,006 Previously recognized as unrealized gains (4,789 ) 4,789 — Total investment dispositions during the period (4,789 ) 20,795 16,006 Investment income $ 77,296 $ 20,795 $ 98,091

Other assets (Tables)

Other assets (Tables)	6 Months Ended
Other assets (Tables)	Jun. 30, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Assets	The following table summarizes the components of other assets as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Acquired below-market ground leases $ 17,624 $ 12,684 Acquired in-place leases 134,809 64,979 Deferred compensation plan 19,400 15,534 Deferred financing costs – $1.65 billion unsecured senior line of credit 8,667 10,525 Deposits 5,275 10,576 Furniture, fixtures, and equipment 11,538 11,070 Interest rate hedge assets 5,991 5,260 Net investment in direct financing lease 38,763 38,382 Notes receivable 572 614 Prepaid expenses 13,097 10,972 Property, plant, and equipment 56,841 32,073 Other assets 21,180 15,784 Total $ 333,757 $ 228,453
Net Investment in Direct Financing Lease	The components of our net investment in direct financing lease as of June 30, 2018 , and December 31, 2017 , are summarized in the table below (in thousands): June 30, 2018 December 31, 2017 Gross investment in direct financing lease $ 262,918 $ 263,719 Less: unearned income (224,155 ) (225,337 ) Net investment in direct financing lease $ 38,763 $ 38,382
Schedule of future minimum lease payments to be received on direct financing lease	Future minimum lease payments to be received under our direct financing lease as of June 30, 2018 , were as follows (in thousands): Year Total 2018 $ 806 2019 1,655 2020 1,705 2021 1,756 2022 1,809 Thereafter 255,187 Total $ 262,918

Fair value measurements (Tables

Fair value measurements (Tables)	6 Months Ended
Fair value measurements (Tables)	Jun. 30, 2018
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 June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 Description Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Investments in publicly traded companies $ 198,616 $ 198,616 $ — $ — Interest rate hedge agreements $ 5,991 $ — $ 5,991 $ — December 31, 2017 Description Total Quoted Prices in Significant Significant Assets: Investments in publicly traded companies $ 109,511 $ 109,511 $ — $ — Interest rate hedge agreements $ 5,260 $ — $ 5,260 $ — Liabilities: Interest rate hedge agreements $ 103 $ — $ 103 $ —
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 June 30, 2018 , and December 31, 2017 , the book and estimated fair values of our investments in privately held entities that report NAV, secured notes payable, unsecured senior notes payable, unsecured senior line of credit, and unsecured senior bank term loans were as follows (in thousands): June 30, 2018 December 31, 2017 Book Value Fair Value Book Value Fair Value Assets: Investments in privately held entities that report NAV $ 284,656 $ 284,656 N/A N/A Liabilities: Secured notes payable $ 776,260 $ 774,955 $ 771,061 $ 776,222 Unsecured senior notes payable $ 4,289,521 $ 4,300,275 $ 3,395,804 $ 3,529,713 Unsecured senior line of credit $ — $ — $ 50,000 $ 49,986 Unsecured senior bank term loans $ 548,324 $ 550,280 $ 547,942 $ 549,361

Secured and unsecured senior 31

Secured and unsecured senior debt (Tables)	6 Months Ended
Secured and unsecured senior debt (Tables)	Jun. 30, 2018
Debt Disclosure [Abstract]
Summary of secured and unsecured debt	The following table summarizes our secured and unsecured senior debt as of June 30, 2018 (dollars in thousands): Fixed-Rate/Hedged Variable-Rate Debt Unhedged Variable-Rate Debt Weighted-Average Interest Remaining Term (in years) Total Percentage Rate (1) Secured notes payable $ 491,897 $ 284,363 $ 776,260 13.8 % 4.28 % 2.8 Unsecured senior notes payable 4,289,521 — 4,289,521 76.4 4.15 6.9 $1.65 billion unsecured senior line of credit — — — — N/A 3.3 2019 Unsecured Senior Bank Term Loan 199,620 — 199,620 3.6 2.75 0.5 2021 Unsecured Senior Bank Term Loan 348,704 — 348,704 6.2 2.41 2.5 Total/weighted average $ 5,329,742 $ 284,363 $ 5,614,105 100.0 % 4.01 % 5.8 Percentage of total debt 95 % 5 % 100 % (1) Represents the weighted-average interest rate as of the end of the applicable period, including expense/income related to our interest rate hedge agreements, amortization of loan fees, amortization of debt premiums (discounts), and other bank fees.
Schedule of maturities of secured and unsecured debt	The following table summarizes our outstanding indebtedness and respective principal payments as of June 30, 2018 (dollars in thousands): Stated Rate Interest Rate (1) Maturity Date (2) Unamortized (Deferred Financing Cost), (Discount)/Premium Debt Principal Total Secured notes payable Greater Boston L+1.50 % 3.82 % 1/28/19 (3) $ 334,363 $ (698 ) $ 333,665 Greater Boston, San Diego, Seattle, and Maryland 7.75 % 8.15 4/1/20 107,499 (585 ) 106,914 San Diego 4.66 % 4.90 1/1/23 34,175 (296 ) 33,879 Greater Boston 3.93 % 3.19 3/10/23 81,640 2,566 84,206 Greater Boston 4.82 % 3.40 2/6/24 201,986 14,848 216,834 San Francisco 6.50 % 6.50 7/1/36 762 — 762 Secured debt weighted-average interest rate/subtotal 4.60 % 4.28 760,425 15,835 776,260 2019 Unsecured Senior Bank Term Loan L+1.20 % 2.75 1/3/19 200,000 (380 ) 199,620 2021 Unsecured Senior Bank Term Loan L+1.10 % 2.41 1/15/21 350,000 (1,296 ) 348,704 $1.65 billion unsecured senior line of credit L+1.00 % N/A 10/29/21 — — — Unsecured senior notes payable 2.75 % 2.96 1/15/20 400,000 (1,237 ) 398,763 Unsecured senior notes payable 4.60 % 4.75 4/1/22 550,000 (2,438 ) 547,562 Unsecured senior notes payable 3.90 % 4.04 6/15/23 500,000 (2,945 ) 497,055 Unsecured senior notes payable 4.00 % 4.18 1/15/24 450,000 (4,050 ) 445,950 Unsecured senior notes payable 3.45 % 3.62 4/30/25 600,000 (5,954 ) 594,046 Unsecured senior notes payable 4.30 % 4.50 1/15/26 300,000 (3,648 ) 296,352 Unsecured senior notes payable 3.95 % 4.13 1/15/27 350,000 (4,278 ) 345,722 Unsecured senior notes payable 3.95 % 4.07 1/15/28 425,000 (4,024 ) 420,976 Unsecured senior notes payable 4.50 % 4.60 7/30/29 300,000 (2,452 ) 297,548 Unsecured senior notes payable 4.70 % 4.81 7/1/30 450,000 (4,453 ) 445,547 Unsecured debt weighted average/subtotal 3.96 4,875,000 (37,155 ) 4,837,845 Weighted-average interest rate/total 4.01 % $ 5,635,425 $ (21,320 ) $ 5,614,105 (1) Represents the weighted-average interest rate as of the end of the applicable period, including expense/income related to our interest rate hedge agreements, amortization of loan fees, amortization of debt premiums (discounts), and other bank fees. (2) Reflects any extension options that we control. (3) Secured construction loan for our property at 50 and 60 Binney Street in our Cambridge submarket with aggregate commitments of $350.0 million as of June 30, 2018 . We have two one -year options to extend the stated maturity date to January 28, 2021, subject to certain conditions. In July 2018, we completed a partial repayment of $150.0 million of the outstanding balance and reduced aggregate commitments to $200.0 million .
Schedule of Interest Incurred	The following table summarizes interest expense for the three and six months ended June 30, 2018 and 2017 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Gross interest $ 53,624 $ 46,817 $ 103,899 $ 89,765 Capitalized interest (15,527 ) (15,069 ) (28,887 ) (28,233 ) Interest expense $ 38,097 $ 31,748 $ 75,012 $ 61,532

Interest rate hedge agreements

Interest rate hedge agreements (Tables)	6 Months Ended
Interest rate hedge agreements (Tables)	Jun. 30, 2018
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 hedge agreements that were designated as cash flow hedges of interest rate risk as of June 30, 2018 (dollars in thousands): Number of Contracts Weighted-Average Interest Pay Rate (1) Fair Value as of 6/30/18 Notional Amount in Effect as of Effective Date Maturity Date 6/30/18 12/31/18 12/31/19 March 29, 2018 March 31, 2019 8 1.16% $ 5,142 $ 600,000 $ 600,000 $ — March 29, 2019 March 31, 2020 1 1.89% 849 — — 100,000 Total $ 5,991 $ 600,000 $ 600,000 $ 100,000 (1) In addition to the interest pay rate for each swap agreement, interest is payable at an applicable margin over LIBOR for borrowings outstanding as of June 30, 2018 , as listed under the column heading “Stated Rate” in our summary table of outstanding indebtedness and respective principal payments under Note 9 – “Secured and Unsecured Senior Debt” to these unaudited consolidated financial statements.

Accounts payable, accrued exp33

Accounts payable, accrued expenses, and tenant security deposits (Tables)	6 Months Ended
	Jun. 30, 2018
Accounts payable, accrued expenses, and tenant security deposits [Abstract]
Schedule of accounts payable and accrued liabilities	The following table summarizes the components of accounts payable, accrued expenses, and tenant security deposits as of June 30, 2018 , and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Accounts payable and accrued expenses $ 394,435 $ 349,884 Acquired below-market leases 123,402 88,184 Conditional asset retirement obligations 10,519 7,397 Deferred rent liabilities 28,367 27,953 Interest rate hedge liabilities — 103 Unearned rent and tenant security deposits 248,543 248,924 Other liabilities 44,008 41,387 Total $ 849,274 $ 763,832

Earnings per share (Tables)

Earnings per share (Tables)	6 Months Ended
Earnings per share (Tables)	Jun. 30, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
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 three and six months ended June 30, 2018 and 2017 (in thousands, except per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Net income $ 60,547 $ 41,496 $ 202,065 $ 89,051 Net income attributable to noncontrolling interests (5,817 ) (7,275 ) (11,705 ) (13,119 ) Dividends on preferred stock (1,302 ) (1,278 ) (2,604 ) (5,062 ) Preferred stock redemption charge — — — (11,279 ) Net income attributable to unvested restricted stock awards (1,412 ) (1,313 ) (2,765 ) (2,300 ) Numerator for basic and diluted EPS – net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders $ 52,016 $ 31,630 $ 184,991 $ 57,291 Denominator for basic EPS – weighted-average shares of common stock outstanding 101,881 90,215 100,878 89,186 Dilutive effect of forward equity sales agreements 355 530 313 293 Denominator for diluted EPS – weighted-average shares of common stock outstanding 102,236 90,745 101,191 89,479 Net income per share attributable to Alexandria Real Estate Equities, Inc.’s common stockholders: Basic $ 0.51 $ 0.35 $ 1.83 $ 0.64 Diluted $ 0.51 $ 0.35 $ 1.83 $ 0.64

Stockholders' equity (Tables)

Stockholders' equity (Tables)	6 Months Ended
Stockholders' equity (Tables)	Jun. 30, 2018
Stockholders' Equity Note [Abstract]
Accumulated other comprehensive loss attributable to Alexandria Real Estate Equities, Inc.	Accumulated other comprehensive income attributable to Alexandria Real Estate Equities, Inc. consists of the following (in thousands): Net Unrealized Gain (Loss) on: Available-for- Sale Equity Securities Interest Rate Foreign Currency Translation Total Balance as of December 31, 2017 $ 49,771 $ 5,157 $ (4,904 ) $ 50,024 Amounts reclassified from other comprehensive income to retained earnings (49,771 ) (1) — — (49,771 ) Other comprehensive income (loss) before reclassifications — 2,643 (3,572 ) (929 ) Amounts reclassified from other comprehensive income to net income — (1,809 ) — (1,809 ) Net other comprehensive income — 834 (3,572 ) (2,738 ) Balance as of June 30, 2018 $ — $ 5,991 $ (8,476 ) $ (2,485 ) (1) Refer to Note 6 – “Investments” to these unaudited consolidated financial statements for additional information.

Assets classified as held for36

Assets classified as held for sale (Tables)	6 Months Ended
Assets classified as held for sale (Tables)	Jun. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Summary of net assets of discontinued operations and (loss) income from discontinued operations, net	The following is a summary of net assets as of June 30, 2018 , and December 31, 2017 , for our real estate investments that were classified as held for sale in each respective period (in thousands): June 30, 2018 December 31, 2017 Total assets $ 41,934 $ 31,578 Total liabilities (1,789 ) (1,809 ) Total accumulated other comprehensive income (436 ) (1,021 ) Net assets classified as held for sale $ 39,709 $ 28,748

Condensed consolidating finan37

Condensed consolidating financial information (Tables)	6 Months Ended
Condensed consolidating financial information (Tables)	Jun. 30, 2018
Condensed Consolidated Financial Information [Abstract]
Condensed consolidating balance sheet	Condensed Consolidating Balance Sheet as of June 30, 2018 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Assets Investments in real estate $ — $ — $ 11,190,771 $ — $ 11,190,771 Investments in unconsolidated real estate JVs — — 192,972 — 192,972 Cash and cash equivalents 181,342 — 105,687 — 287,029 Restricted cash 155 — 34,657 — 34,812 Tenant receivables — — 8,704 — 8,704 Deferred rent — — 490,428 — 490,428 Deferred leasing costs — — 232,964 — 232,964 Investments — 1,690 789,063 — 790,753 Investments in and advances to affiliates 11,253,161 10,066,773 205,029 (21,524,963 ) — Other assets 51,551 — 282,206 — 333,757 Total assets $ 11,486,209 $ 10,068,463 $ 13,532,481 $ (21,524,963 ) $ 13,562,190 Liabilities, Noncontrolling Interests, and Equity Secured notes payable $ — $ — $ 776,260 $ — $ 776,260 Unsecured senior notes payable 4,289,521 — — — 4,289,521 Unsecured senior line of credit — — — — — Unsecured senior bank term loans 548,324 — — — 548,324 Accounts payable, accrued expenses, and tenant security deposits 89,227 — 760,047 — 849,274 Dividends payable 98,676 — — — 98,676 Total liabilities 5,025,748 — 1,536,307 — 6,562,055 Redeemable noncontrolling interests — — 10,861 — 10,861 Alexandria Real Estate Equities, Inc.’s stockholders’ equity 6,460,461 10,068,463 11,456,500 (21,524,963 ) 6,460,461 Noncontrolling interests — — 528,813 — 528,813 Total equity 6,460,461 10,068,463 11,985,313 (21,524,963 ) 6,989,274 Total liabilities, noncontrolling interests, and equity $ 11,486,209 $ 10,068,463 $ 13,532,481 $ (21,524,963 ) $ 13,562,190 Condensed Consolidating Balance Sheet as of December 31, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Assets Investments in real estate $ — $ — $ 10,298,019 $ — $ 10,298,019 Investments in unconsolidated real estate JVs — — 110,618 — 110,618 Cash and cash equivalents 130,364 9 124,008 — 254,381 Restricted cash 152 — 22,653 — 22,805 Tenant receivables — — 10,262 — 10,262 Deferred rent — — 434,731 — 434,731 Deferred leasing costs — — 221,430 — 221,430 Investments — 1,655 521,599 — 523,254 Investments in and advances to affiliates 9,949,861 9,030,994 183,850 (19,164,705 ) — Other assets 45,108 — 183,345 — 228,453 Total assets $ 10,125,485 $ 9,032,658 $ 12,110,515 $ (19,164,705 ) $ 12,103,953 Liabilities, Noncontrolling Interests, and Equity Secured notes payable $ — $ — $ 771,061 $ — $ 771,061 Unsecured senior notes payable 3,395,804 — — — 3,395,804 Unsecured senior line of credit 50,000 — — — 50,000 Unsecured senior bank term loans 547,942 — — — 547,942 Accounts payable, accrued expenses, and tenant security deposits 89,928 — 673,904 — 763,832 Dividends payable 92,145 — — — 92,145 Total liabilities 4,175,819 — 1,444,965 — 5,620,784 Redeemable noncontrolling interests — — 11,509 — 11,509 Alexandria Real Estate Equities, Inc.’s stockholders’ equity 5,949,666 9,032,658 10,132,047 (19,164,705 ) 5,949,666 Noncontrolling interests — — 521,994 — 521,994 Total equity 5,949,666 9,032,658 10,654,041 (19,164,705 ) 6,471,660 Total liabilities, noncontrolling interests, and equity $ 10,125,485 $ 9,032,658 $ 12,110,515 $ (19,164,705 ) $ 12,103,953
Condensed consolidating statements of income	Condensed Consolidating Statement of Income for the Three Months Ended June 30, 2018 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Revenues: Rental $ — $ — $ 250,635 $ — $ 250,635 Tenant recoveries — — 72,159 — 72,159 Other income 4,965 — 3,112 (5,837 ) 2,240 Total revenues 4,965 — 325,906 (5,837 ) 325,034 Expenses: Rental operations — — 91,908 — 91,908 General and administrative 23,001 — 5,775 (5,837 ) 22,939 Interest 32,139 — 5,958 — 38,097 Depreciation and amortization 1,647 — 117,205 — 118,852 Impairment on real estate — — 6,311 — 6,311 Total expenses 56,787 — 227,157 (5,837 ) 278,107 Equity in earnings of unconsolidated real estate JVs — — 1,090 — 1,090 Equity in earnings of affiliates 106,552 98,795 1,943 (207,290 ) — Investment (loss) income — (97 ) 12,627 — 12,530 Net income 54,730 98,698 114,409 (207,290 ) 60,547 Net income attributable to noncontrolling interests — — (5,817 ) — (5,817 ) Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders 54,730 98,698 108,592 (207,290 ) 54,730 Dividends on preferred stock (1,302 ) — — — (1,302 ) Net income attributable to unvested restricted stock awards (1,412 ) — — — (1,412 ) Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders $ 52,016 $ 98,698 $ 108,592 $ (207,290 ) $ 52,016 Condensed Consolidating Statement of Income for the Three Months Ended June 30, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Revenues: Rental $ — $ — $ 211,942 $ — $ 211,942 Tenant recoveries — — 60,470 — 60,470 Other income 4,124 1 1,482 (4,960 ) 647 Total revenues 4,124 1 273,894 (4,960 ) 273,059 Expenses: Rental operations — — 76,980 — 76,980 General and administrative 19,428 — 4,766 (4,960 ) 19,234 Interest 21,831 — 9,917 — 31,748 Depreciation and amortization 1,721 — 102,377 — 104,098 Impairment of real estate — — 203 — 203 Total expenses 42,980 — 194,243 (4,960 ) 232,263 Equity in earnings of unconsolidated real estate JVs — — 589 — 589 Equity in earnings of affiliates 73,077 70,597 1,360 (145,034 ) — Gain on sales of real estate – land parcels — — 111 — 111 Net income 34,221 70,598 81,711 (145,034 ) 41,496 Net income attributable to noncontrolling interests — — (7,275 ) — (7,275 ) Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders 34,221 70,598 74,436 (145,034 ) 34,221 Dividends on preferred stock (1,278 ) — — — (1,278 ) Net income attributable to unvested restricted stock awards (1,313 ) — — — (1,313 ) Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders $ 31,630 $ 70,598 $ 74,436 $ (145,034 ) $ 31,630
Condensed consolidating statement comprehensive income	Condensed Consolidating Statement of Comprehensive Income for the Three Months Ended June 30, 2018 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Net income $ 54,730 $ 98,698 $ 114,409 $ (207,290 ) $ 60,547 Other comprehensive (loss) income Unrealized losses on interest rate hedge agreements: Unrealized interest rate hedge gains arising during the period 661 — — — 661 Reclassification adjustment for amortization of interest income included in net income (1,131 ) — — — (1,131 ) Unrealized losses on interest rate hedge agreements, net (470 ) — — — (470 ) Unrealized losses on foreign currency translation: Unrealized foreign currency translation losses arising during the period — — (3,243 ) — (3,243 ) Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation — — — — — Unrealized losses on foreign currency translation, net — — (3,243 ) — (3,243 ) Total other comprehensive loss (470 ) — (3,243 ) — (3,713 ) Comprehensive income 54,260 98,698 111,166 (207,290 ) 56,834 Less: comprehensive income attributable to noncontrolling interests — — (5,817 ) — (5,817 ) Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders $ 54,260 $ 98,698 $ 105,349 $ (207,290 ) $ 51,017 Condensed Consolidating Statement of Comprehensive Income for the Three Months Ended June 30, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non- Guarantor Subsidiaries Eliminations Consolidated Net income $ 34,221 $ 70,598 $ 81,711 $ (145,034 ) $ 41,496 Other comprehensive income Unrealized losses on available-for-sale equity securities: Unrealized holding losses arising during the period — (1 ) (4,024 ) — (4,025 ) Reclassification adjustment for losses included in net income — 1 2,348 — 2,349 Unrealized losses on available-for-sale equity securities, net — — (1,676 ) — (1,676 ) Unrealized gains (losses) on interest rate hedge agreements: Unrealized interest rate hedge losses arising during the period (411 ) — (139 ) — (550 ) Reclassification adjustment for amortization of interest expense included in net income 705 — 2 — 707 Unrealized gains (losses) on interest rate hedge agreements, net 294 — (137 ) — 157 Unrealized gains on foreign currency translation: Unrealized foreign currency translation gains arising during the period — — 2,744 — 2,744 Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation — — — — — Unrealized gains on foreign currency translation, net — — 2,744 — 2,744 Total other comprehensive income 294 — 931 — 1,225 Comprehensive income 34,515 70,598 82,642 (145,034 ) 42,721 Less: comprehensive income attributable to noncontrolling interests — — (7,283 ) — (7,283 ) Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders $ 34,515 $ 70,598 $ 75,359 $ (145,034 ) $ 35,438
Condensed consolidating statement cash flows	Condensed Consolidating Statement of Cash Flows for the Six Months Ended June 30, 2018 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non-Guarantor Subsidiaries Eliminations Consolidated Operating Activities Net income $ 190,360 $ 198,053 $ 307,946 $ (494,294 ) $ 202,065 Adjustments to reconcile net income to net cash (used in) provided by operating activities: Depreciation and amortization 3,324 — 229,747 — 233,071 Impairment of real estate — — 6,311 — 6,311 Equity in earnings of unconsolidated real estate JVs — — (2,234 ) — (2,234 ) Distributions of earnings from unconsolidated real estate JVs — — 287 — 287 Amortization of loan fees 4,260 — 876 — 5,136 Amortization of debt discounts (premiums) 378 — (1,559 ) — (1,181 ) Amortization of acquired below-market leases — — (11,368 ) — (11,368 ) Deferred rent — — (55,890 ) — (55,890 ) Stock compensation expense 15,223 — — — 15,223 Equity in earnings of affiliates (292,720 ) (197,677 ) (3,897 ) 494,294 — Investment income 43 (375 ) (97,759 ) — (98,091 ) Changes in operating assets and liabilities: Tenant receivables — — 1,552 — 1,552 Deferred leasing costs — — (29,705 ) — (29,705 ) Other assets (10,894 ) — (4,161 ) — (15,055 ) Accounts payable, accrued expenses, and tenant security deposits (726 ) (2 ) 8,848 — 8,120 Net cash (used in) provided by operating activities (90,752 ) (1 ) 348,994 — 258,241 Investing Activities Additions to real estate — — (431,225 ) — (431,225 ) Purchases of real estate — — (688,698 ) — (688,698 ) Deposits for investing activities — — 5,500 — 5,500 Investments in subsidiaries (1,010,580 ) (838,102 ) (17,282 ) 1,865,964 — Acquisitions of interests in unconsolidated real estate JVs — — (35,922 ) — (35,922 ) Investments in unconsolidated real estate JVs — — (44,486 ) — (44,486 ) Additions to investments — — (118,775 ) — (118,775 ) Sales of investments — 377 44,330 — 44,707 Net cash used in investing activities $ (1,010,580 ) $ (837,725 ) $ (1,286,558 ) $ 1,865,964 $ (1,268,899 ) Condensed Consolidating Statement of Cash Flows (continued) for the Six Months Ended June 30, 2018 (In thousands) (Unaudited) Alexandria Real Alexandria Real Combined Eliminations Consolidated Financing Activities Borrowings from secured notes payable $ — $ — $ 9,044 $ — $ 9,044 Repayments of borrowings from secured notes payable — — (3,162 ) — (3,162 ) Proceeds from issuance of unsecured senior notes payable 899,321 — — — 899,321 Borrowings from unsecured senior line of credit 2,469,000 — — — 2,469,000 Repayments of borrowings from unsecured senior line of credit (2,519,000 ) — — — (2,519,000 ) Transfers to/from parent company 96,432 837,717 931,815 (1,865,964 ) — Payment of loan fees (8,003 ) — — — (8,003 ) Proceeds from the issuance of common stock 400,207 — — — 400,207 Dividends on common stock (183,040 ) — — — (183,040 ) Dividends on preferred stock (2,604 ) — — — (2,604 ) Contributions from noncontrolling interests — — 14,564 — 14,564 Distributions to and purchases of noncontrolling interests — — (19,841 ) — (19,841 ) Net cash provided by financing activities 1,152,313 837,717 932,420 (1,865,964 ) 1,056,486 Effect of foreign exchange rate changes on cash and cash equivalents — — (1,173 ) — (1,173 ) Net increase (decrease) in cash, cash equivalents, and restricted cash 50,981 (9 ) (6,317 ) — 44,655 Cash, cash equivalents, and restricted cash as of the beginning of period 130,516 9 146,661 — 277,186 Cash, cash equivalents, and restricted cash as of the end of period $ 181,497 $ — $ 140,344 $ — $ 321,841 Supplemental Disclosure of Cash Flow Information: Cash paid during the period for interest, net of interest capitalized $ 56,392 $ — $ 12,493 $ — $ 68,885 Non-Cash Investing Activities: Change in accrued construction $ — $ — $ 48,074 $ — $ 48,074 Condensed Consolidating Statement of Cash Flows for the Six Months Ended June 30, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non-Guarantor Subsidiaries Eliminations Consolidated Operating Activities Net income $ 75,932 $ 153,457 $ 175,647 $ (315,985 ) $ 89,051 Adjustments to reconcile net income to net cash (used in) provided by operating activities: Depreciation and amortization 3,430 — 197,851 — 201,281 Loss on early extinguishment of debt 670 — — — 670 Gain on sales of real estate – rental properties — — (270 ) — (270 ) Impairment of real estate — — 203 — 203 Gain on sales of real estate – land parcels — — (111 ) — (111 ) Equity in losses of unconsolidated real estate JVs — — (950 ) — (950 ) Distributions of earnings from unconsolidated real estate JVs — — 249 — 249 Amortization of loan fees 3,774 — 1,964 — 5,738 Amortization of debt discounts (premiums) 290 — (1,511 ) — (1,221 ) Amortization of acquired below-market leases — — (10,363 ) — (10,363 ) Deferred rent — — (53,497 ) — (53,497 ) Stock compensation expense 10,756 — — — 10,756 Equity in earnings of affiliates (159,548 ) (153,445 ) (2,992 ) 315,985 — Investment income — (5 ) (957 ) — (962 ) Changes in operating assets and liabilities: Tenant receivables — — 1,354 — 1,354 Deferred leasing costs — — (26,811 ) — (26,811 ) Other assets (8,947 ) — 4,293 — (4,654 ) Accounts payable, accrued expenses, and tenant security deposits (7,109 ) (12 ) 20,404 — 13,283 Net cash (used in) provided by operating activities (80,752 ) (5 ) 304,503 — 223,746 Investing Activities Proceeds from sales of real estate — — 3,528 — 3,528 Additions to real estate — — (436,377 ) — (436,377 ) Purchases of real estate — — (480,543 ) — (480,543 ) Deposits for investing activities — — 450 — 450 Investments in subsidiaries (573,334 ) (464,024 ) (9,565 ) 1,046,923 — Investments in unconsolidated real estate JVs — — (163 ) — (163 ) Additions to investments — — (81,192 ) — (81,192 ) Sales of investments — 204 12,373 — 12,577 Net cash used in investing activities $ (573,334 ) $ (463,820 ) $ (991,489 ) $ 1,046,923 $ (981,720 ) Condensed Consolidating Statement of Cash Flows (continued) for the Six Months Ended June 30, 2017 (In thousands) (Unaudited) Alexandria Real Estate Equities, Inc. (Issuer) Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary) Combined Non-Guarantor Subsidiaries Eliminations Consolidated Financing Activities Borrowings from secured notes payable $ — $ — $ 117,666 $ — $ 117,666 Repayments of borrowings from secured notes payable — — (1,677 ) — (1,677 ) Proceeds from issuance of unsecured senior notes payable 424,384 — — — 424,384 Borrowings from unsecured senior line of credit 2,069,000 — — — 2,069,000 Repayments of borrowings from unsecured senior line of credit (1,797,000 ) — — — (1,797,000 ) Repayments of borrowings from unsecured bank term loans (200,000 ) — — — (200,000 ) Transfers to/from parent company 21,995 463,825 561,103 (1,046,923 ) — Payment of loan fees (3,957 ) — (387 ) — (4,344 ) Repurchase of 7.00% Series D cumulative convertible preferred stock (17,934 ) — — — (17,934 ) Redemption of 6.45% Series E cumulative redeemable preferred stock (130,350 ) — — — (130,350 ) Proceeds from the issuance of common stock 459,607 — — — 459,607 Dividends on common stock (149,296 ) — — — (149,296 ) Dividends on preferred stock (7,015 ) — — — (7,015 ) Contributions from noncontrolling interests — — 8,505 — 8,505 Distributions to and purchases of noncontrolling interests — — (10,791 ) — (10,791 ) Net cash provided by financing activities 669,434 463,825 674,419 (1,046,923 ) 760,755 Effect of foreign exchange rate changes on cash and cash equivalents — — 732 — 732 Net increase (decrease) in cash, cash equivalents, and restricted cash 15,348 — (11,835 ) — 3,513 Cash, cash equivalents, and restricted cash as of the beginning of period 30,705 — 110,661 — 141,366 Cash, cash equivalents, and restricted cash as of the end of period $ 46,053 $ — $ 98,826 $ — $ 144,879 Supplemental Disclosure of Cash Flow Information: Cash paid during the period for interest, net of interest capitalized $ 41,598 $ — $ 12,212 $ — $ 53,810 Non-Cash Investing Activities: Change in accrued construction $ — $ — $ (25,138 ) $ — $ (25,138 ) Contribution of real estate to an unconsolidated real estate JV $ — $ — $ 6,998 $ — $ 6,998

Summary of significant accoun38

Summary of significant accounting policies (Details)	3 Months Ended		6 Months Ended
Summary of significant accounting policies (Details)	Jun. 30, 2018USD ($)property	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)property	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Property, plant and equipment depreciated on a straight-line basis using an estimated life
Maximum expected period of sale of property (in years)			1 year
Cost method investment ownership percentage	10.00%		10.00%		10.00%
Reclassification of cumulative net unrealized gains on non-real estate investments			$ 90,750,000
Maximum Expected Period for Collection of Receivables			1 year
Allowance for Doubtful Accounts Receivable	$ 0		$ 0		$ 0
Minimum percentage of taxable income to be distributed			90.00%
Percent of Taxable Income, Generally Distributed as Dividend			100.00%
Revenues
Revenue	$ 325,034,000	$ 273,059,000	$ 645,173,000	$ 543,936,000
Land improvements \| Maximum
Property, plant and equipment depreciated on a straight-line basis using an estimated life
Estimated useful life			20 years
Buildings and building improvements \| Maximum
Property, plant and equipment depreciated on a straight-line basis using an estimated life
Estimated useful life			40 years
Canada
Property, plant and equipment depreciated on a straight-line basis using an estimated life
Number of Real Estate Properties \| property	3		3
China
Property, plant and equipment depreciated on a straight-line basis using an estimated life
Number of Real Estate Properties \| property	1		1
Accumulated Other Comprehensive Income
Property, plant and equipment depreciated on a straight-line basis using an estimated life
Reclassification of cumulative net unrealized gains on non-real estate investments			$ (49,771,000)
Rental revenues
Revenues
Revenue	$ 250,635,000	211,942,000	495,120,000	419,135,000
Tenant recoveries
Revenues
Revenue	72,159,000	60,470,000	145,329,000	121,816,000
Other income
Revenues
Revenue	2,240,000	$ 647,000	4,724,000	$ 2,985,000
Accounting Standards Update 2014-09 - Revenue from Contract with Customers
Revenues
Revenue subject to the ASU on recognition of revenue arising from contracts with customers	13,582,000		26,035,000
Accounting Standards Update 2014-09 - Revenue from Contract with Customers \| Rental revenues
Revenues
Revenue subject to the ASU on recognition of revenue arising from contracts with customers	12,086,000		22,519,000
Accounting Standards Update 2014-09 - Revenue from Contract with Customers \| Tenant recoveries
Revenues
Revenue subject to the ASU on recognition of revenue arising from contracts with customers	0		0
Accounting Standards Update 2014-09 - Revenue from Contract with Customers \| Other income
Revenues
Revenue subject to the ASU on recognition of revenue arising from contracts with customers	1,496,000		3,516,000
Other accounting standards update
Revenues
Revenues subject to new accounting pronouncements	311,452,000		619,138,000
Other accounting standards update \| Rental revenues
Revenues
Revenues subject to new accounting pronouncements	238,549,000		472,601,000
Other accounting standards update \| Tenant recoveries
Revenues
Revenues subject to new accounting pronouncements	72,159,000		145,329,000
Other accounting standards update \| Other income
Revenues
Revenues subject to new accounting pronouncements	$ 744,000		$ 1,208,000

Summary of significant accoun39

Summary of significant accounting policies (Recent Accounting Pronouncements) (Details)	6 Months Ended
	Jun. 30, 2018USD ($)ft²	Dec. 31, 2066USD ($)
Leases
Ground Lease Obligation Capitalized Costs	$ 9,200,000
Ground Lease Obligation Capitalized Costs (per RSF)	0.36
Initial direct leasing costs	33,300,000
Initial direct leasing costs (per RSF)	1.30
Ground Lease Obligation Due	610,800,000
Accounting Standards Update 2016-02 - Leases
New Accounting Pronouncement, Early Adoption
Revenues subject to new accounting pronouncements	$ 617,900,000
Ground lease
Leases
Weighted average lease term	47 years
Ground lease \| Minimum
Leases
Weighted average incremental borrowing rate	5.00%
Ground lease \| Maximum
Leases
Weighted average incremental borrowing rate	6.00%
Scenario, Forecast \| Minimum
Leases
Present value of ground and office lease agreements		$ 200,000,000
Scenario, Forecast \| Maximum
Leases
Present value of ground and office lease agreements		$ 230,000,000
Rental revenues \| Accounting Standards Update 2016-02 - Leases
New Accounting Pronouncement, Early Adoption
Revenues subject to new accounting pronouncements	$ 472,600,000
Tenant recoveries \| Accounting Standards Update 2016-02 - Leases
New Accounting Pronouncement, Early Adoption
Revenues subject to new accounting pronouncements	$ 145,300,000
Lease Executed
Leases
Number of leases executed	76
Area of Real Estate Property \| ft²	2,467,160
Weighted average lease term	10 years 5 months
Percent of leases negotiated directly with tenants	51.00%

Investments in real estate Sche

Investments in real estate Schedule of investment in real estates (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Real Estate Properties
Investments in real estate	$ 11,190,771	$ 10,298,019
North America
Real Estate Properties
Land (related to rental properties)	1,442,071	1,312,072
Buildings and building improvements	9,559,442	9,000,626
Other improvements	880,549	780,117
Rental properties	11,882,062	11,092,815
Development and redevelopment projects (under construction, marketing, or pre-construction)	1,253,419	955,218
Future development projects	92,473	96,112
Gross investments in real estate	13,227,954	12,144,145
Less: accumulated depreciation	(2,066,333)	(1,875,810)
Investments in real estate	11,161,621	10,268,335
Asia
Real Estate Properties
Investments in real estate	$ 29,150	$ 29,684

Investments in real estate Acqu

Investments in real estate Acquisition (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2018USD ($)ft²	Jun. 30, 2018USD ($)ft²Lease	Mar. 31, 2018USD ($)aft²Lease	Jun. 30, 2018USD ($)ft²
Real Estate
Purchase price \| $		$ 405,855	$ 339,400	$ 1,002,255
Subsequent Event
Real Estate
Purchase price \| $	$ 257,000
Ground lease
Real Estate
Weighted average lease term				47 years
1655 and 1725 Third Street \| Equity Method Investee
Real Estate
Area of Real Estate Property		593,765	593,765	593,765
Payments to Acquire Interest in Joint Venture \| $			$ 32,000
Equity interest percentage (in percent)		10.00%	10.00%	10.00%
704 Quince Orchard Road \| Equity Method Investee
Real Estate
Area of Real Estate Property		79,931	79,931	79,931
Payments to Acquire Interest in Joint Venture \| $			$ 3,900
Equity interest percentage (in percent)		56.80%	56.80%	56.80%
Operating property
Real Estate
Area of Real Estate Property		782,388	487,227	782,388
Operating property \| Subsequent Event
Real Estate
Area of Real Estate Property	45,626
Operating property \| North America
Real Estate
Area of Real Estate Property		1,315,241		1,315,241
Operating with active or future redevelopment
Real Estate
Area of Real Estate Property		39,505	106,733	39,505
Operating with active or future redevelopment \| Subsequent Event
Real Estate
Area of Real Estate Property	349,947
Operating with active or future redevelopment \| North America
Real Estate
Area of Real Estate Property		496,185		496,185
Operating with active or future redevelopment \| 704 Quince Orchard Road \| Equity Method Investee
Real Estate
Area of Real Estate Property			58,186
Active or future development
Real Estate
Area of Real Estate Property		793,000	643,765	793,000
Active or future development \| Subsequent Event
Real Estate
Area of Real Estate Property	217,000
Active or future development \| North America
Real Estate
Area of Real Estate Property		1,653,765		1,653,765
Summers Ridge Science Park
Real Estate
Area of Real Estate Property			316,531
Purchase price \| $			$ 148,700
Tenant lease term			15 years
Summers Ridge Science Park \| Active or future development
Real Estate
Area of Land			50,000
Alexandria PARC
Real Estate
Area of Real Estate Property			197,498
Area of Land \| a			11
Purchase price \| $			$ 136,000
Weighted average lease term			3 years
Alexandria PARC \| Leases, Acquired-in-Place
Real Estate
Number of Leases Held \| Lease			14
Alexandria PARC \| Operating with active or future redevelopment
Real Estate
Area of Real Estate Property			48,547
100 Tech Drive
Real Estate
Area of Real Estate Property		200,431		200,431
Purchase price \| $		$ 87,300
Tenant lease term		14 years 6 months
100 Tech Drive \| Active or future development
Real Estate
Area of Real Estate Property		300,000		300,000
Maryland Life Science Portfolio
Real Estate
Area of Real Estate Property		415,611		415,611
Purchase price \| $		$ 146,500
Number of Real Estate Properties		8		8
Weighted average lease term		5 years 8 months
2301 5th Avenue
Real Estate
Area of Real Estate Property		197,136		197,136
Purchase price \| $		$ 95,000
Weighted average lease term		5 years 6 months
Property occupancy		97.40%		97.40%
Below-market rental rate (in percentage)		25.00%		25.00%
2301 5th Avenue \| Leases, Acquired-in-Place
Real Estate
Number of Leases Held \| Lease		3
2301 5th Avenue \| Ground lease
Real Estate
Tenant lease term		54 years
Other acquisitions
Real Estate
Purchase price \| $		$ 58,200
Number of Real Estate Properties		1		1
Number of land parcels		4		4
Other acquisitions \| Active or future development
Real Estate
Area of Real Estate Property		493,000		493,000
July 2018 acquisitions \| Subsequent Event
Real Estate
Purchase price \| $	$ 257,000
Number of Real Estate Properties	3
219 East 42nd Street \| Subsequent Event
Real Estate
Area of Real Estate Property	349,947
Purchase price \| $	$ 203,000
Tenant lease term	6 years
219 East 42nd Street \| Active or future development \| Subsequent Event
Real Estate
Area of Real Estate Property	230,000

Investments in real estate Real

Investments in real estate Real estate asset sales (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)ft²	Mar. 31, 2017USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)ft²
Real Estate
Impairment of real estate	$ 6,311	$ 203		$ 6,311	$ 203
Gain (loss) on sale of real estate - rental properties	0	0		$ 0	$ 270
ATC Prince William
Real Estate
Impairment of real estate	6,300
Proceeds from sale of real estate	$ 6,000
6146 Nancy Ridge Drive
Real Estate
Proceeds from sale of real estate			$ 3,000
Gain (loss) on sale of real estate - rental properties			$ 270
150 Technology Parkway
Real Estate
Impairment of real estate		203
Proceeds from sale of real estate		$ 800
Area of Real Estate Property \| ft²		20,580			20,580

Consolidated and unconsolidat43

Consolidated and unconsolidated real estate joint ventures (Details) - ft²	Jun. 30, 2018	Mar. 31, 2018
225 Binney Street
Schedule of Equity Method Investments
Equity interest percentage (in percent)	30.00%
Area of Real Estate Property	305,212
409/499 Illinois Street
Schedule of Equity Method Investments
Equity interest percentage (in percent)	60.00%
Area of Real Estate Property	455,069
1500 Owens Street
Schedule of Equity Method Investments
Equity interest percentage (in percent)	50.10%
Area of Real Estate Property	158,267
Campus Pointe by Alexandria
Schedule of Equity Method Investments
Equity interest percentage (in percent)	55.00%
Area of Real Estate Property	798,799
9625 Towne Centre Drive
Schedule of Equity Method Investments
Equity interest percentage (in percent)	50.10%
Area of Real Estate Property	163,648
Equity Method Investee \| Menlo Gateway
Schedule of Equity Method Investments
Area of Real Estate Property	772,983
Equity Method Investee \| 1401/1413 Research Boulevard
Schedule of Equity Method Investments
Equity interest percentage (in percent)	65.00%
Area of Real Estate Property	90,000
Equity Method Investee \| 360 Longwood Avenue
Schedule of Equity Method Investments
Equity interest percentage (in percent)	27.50%
Area of Real Estate Property	210,709
Equity Method Investee \| 704 Quince Orchard Road
Schedule of Equity Method Investments
Equity interest percentage (in percent)	56.80%	56.80%
Area of Real Estate Property	79,931	79,931
Equity Method Investee \| 1655 and 1725 Third Street
Schedule of Equity Method Investments
Equity interest percentage (in percent)	10.00%	10.00%
Area of Real Estate Property	593,765	593,765
Initial ownership interest \| Equity Method Investee \| Menlo Gateway
Schedule of Equity Method Investments
Equity interest percentage (in percent)	29.40%

Consolidated and unconsolidat44

Consolidated and unconsolidated real estate joint ventures Consolidated VIE's balance sheet information (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Variable Interest Entity
Investments in real estate	$ 11,190,771	$ 10,298,019
Cash and cash equivalents	287,029	254,381
Other assets	333,757	228,453
Total assets	13,562,190	12,103,953
Secured notes payable	776,260	771,061
Total liabilities	6,562,055	5,620,784
Redeemable noncontrolling interests	10,861	11,509
Alexandria Real Estate Equities, Inc.'s share of equity	6,460,461	5,949,666
Noncontrolling interests' share of equity	528,813	521,994
Total liabilities, noncontrolling interests, and equity	13,562,190	12,103,953
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity
Investments in real estate	1,097,759	1,047,472
Cash and cash equivalents	40,352	41,112
Other assets	70,595	68,754
Total assets	1,208,706	1,157,338
Secured notes payable	0	0
Other Liabilities	69,191	52,201
Total liabilities	69,191	52,201
Redeemable noncontrolling interests	749	0
Alexandria Real Estate Equities, Inc.'s share of equity	610,996	584,160
Noncontrolling interests' share of equity	527,770	520,977
Total liabilities, noncontrolling interests, and equity	$ 1,208,706	$ 1,157,338

Consolidated and unconsolidat45

Consolidated and unconsolidated real estate joint ventures Unconsolidated real estate joint ventures (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments
Investments in unconsolidated real estate joint ventures	$ 192,972		$ 110,618
Weighted-Average Interest Rate at End of Period	4.01%
Long-term Debt	$ 5,614,105
Equity Method Investee
Schedule of Equity Method Investments
Long-term Debt	319,925
Long-term Debt, Remaining Commitments	510,741
Equity Method Investee \| Menlo Gateway
Schedule of Equity Method Investments
Investments in unconsolidated real estate joint ventures	121,785
Equity Method Investee \| 1401/1413 Research Boulevard
Schedule of Equity Method Investments
Investments in unconsolidated real estate joint ventures	$ 7,533
Equity interest percentage (in percent)	65.00%
Equity Method Investee \| 360 Longwood Avenue
Schedule of Equity Method Investments
Investments in unconsolidated real estate joint ventures	$ 25,538
Equity interest percentage (in percent)	27.50%
Equity Method Investee \| 704 Quince Orchard Road
Schedule of Equity Method Investments
Investments in unconsolidated real estate joint ventures	$ 4,384
Equity interest percentage (in percent)	56.80%	56.80%
Equity Method Investee \| 1655 and 1725 Third Street
Schedule of Equity Method Investments
Investments in unconsolidated real estate joint ventures	$ 33,732
Equity interest percentage (in percent)	10.00%	10.00%
Initial ownership interest \| Equity Method Investee \| Menlo Gateway
Schedule of Equity Method Investments
Equity interest percentage (in percent)	29.40%
Secured debt maturing on 3/1/19 \| Equity Method Investee \| Menlo Gateway
Schedule of Equity Method Investments
Maturity Date	Mar. 1, 2019
Weighted-Average Interest Rate at End of Period	4.49%
Long-term Debt	$ 134,564
Long-term Debt, Percentage Bearing Variable Interest, Remaining Commitments	$ 13,290
Secured debt maturing on 5/17/20 \| Equity Method Investee \| 1401/1413 Research Boulevard
Schedule of Equity Method Investments
Maturity Date	May 17, 2020
Weighted-Average Interest Rate at End of Period	5.39%
Long-term Debt	$ 14,682
Long-term Debt, Percentage Bearing Variable Interest, Remaining Commitments	$ 9,892
Secured debt maturing on 6/29/21 \| Equity Method Investee \| 1655 and 1725 Third Street
Schedule of Equity Method Investments
Maturity Date	Jun. 29, 2021
Weighted-Average Interest Rate at End of Period	5.68%
Long-term Debt	$ 75,520
Long-term Debt, Percentage Bearing Variable Interest, Remaining Commitments	$ 299,480
Secured debt maturing on 9/1/22 \| Equity Method Investee \| 360 Longwood Avenue
Schedule of Equity Method Investments
Maturity Date	Sep. 1, 2022
Stated interest rate (as a percent)	3.32%
Weighted-Average Interest Rate at End of Period	3.54%
Long-term Debt	$ 94,143
Long-term Debt, Percentage Bearing Fixed Interest, Remaining Commitments	17,000
Earn-out provisions for incremental borrowing	$ 48,000
Secured debt maturing on 3/16/23 \| Equity Method Investee \| 704 Quince Orchard Road
Schedule of Equity Method Investments
Maturity Date	Mar. 16, 2023
Weighted-Average Interest Rate at End of Period	4.29%
Long-term Debt	$ 1,016
Long-term Debt, Percentage Bearing Variable Interest, Remaining Commitments	$ 13,809
Secured debt maturing on 5/1/35 \| Equity Method Investee \| Menlo Gateway
Schedule of Equity Method Investments
Maturity Date	May 1, 2035
Stated interest rate (as a percent)	4.53%
Weighted-Average Interest Rate at End of Period	4.56%
Long-term Debt	$ 0
Long-term Debt, Percentage Bearing Fixed Interest, Remaining Commitments	$ 157,270
London Interbank Offered Rate (LIBOR) \| Secured debt maturing on 3/1/19 \| Equity Method Investee \| Menlo Gateway
Schedule of Equity Method Investments
Applicable margin (as a percent)	2.50%
London Interbank Offered Rate (LIBOR) \| Secured debt maturing on 5/17/20 \| Equity Method Investee \| 1401/1413 Research Boulevard
Schedule of Equity Method Investments
Applicable margin (as a percent)	2.50%
London Interbank Offered Rate (LIBOR) \| Secured debt maturing on 6/29/21 \| Equity Method Investee \| 1655 and 1725 Third Street
Schedule of Equity Method Investments
Applicable margin (as a percent)	3.70%
London Interbank Offered Rate (LIBOR) \| Secured debt maturing on 3/16/23 \| Equity Method Investee \| 704 Quince Orchard Road
Schedule of Equity Method Investments
Applicable margin (as a percent)	1.95%

Cash, cash equivalents, and r46

Cash, cash equivalents, and restricted cash (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Cash and Cash Equivalents
Cash and cash equivalents	$ 287,029	$ 254,381
Restricted cash	34,812	22,805
Cash, cash equivalents, and restricted cash	321,841	277,186	$ 144,879	$ 141,366
Funds held in trust under the terms of certain secured notes payable
Cash and Cash Equivalents
Restricted cash	14,384	12,301
Funds held in escrow related to construction projects and investing activities
Cash and Cash Equivalents
Restricted cash	16,551	4,546
Other restricted cash
Cash and Cash Equivalents
Restricted cash	$ 3,877	$ 5,958

Investments Summary of Investme

Investments Summary of Investments (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Schedule of Investments
Reclassification of cumulative net unrealized gains on non-real estate investments	$ (90,750)
Investment commitments	$ 190,600
Limited partnership liquidation, expected initial term (in years)	10 years
Weighted average remaining liquidation term (in years)	5 years 5 months
Summary of Investment [Abstract]
Investment at fair value, cost	$ 572,608	$ 473,483
Cumulative unrealized gains (losses) on investments	218,145	49,771
Total investments	790,753	523,254
Accumulated Other Comprehensive Income
Schedule of Investments
Reclassification of cumulative net unrealized gains on non-real estate investments	49,771
Investments in publicly traded companies
Summary of Investment [Abstract]
Investment at fair value, cost	101,603	59,740
Cumulative unrealized gains (losses) on investments	97,013	49,771
Investments at fair value, book value	198,616	109,511
Investments in privately held entities that report NAV
Schedule of Investments
Investment commitments	187,900
Summary of Investment [Abstract]
Investment at fair value, cost	173,813	148,627
Cumulative unrealized gains (losses) on investments	110,843
Investments at fair value, book value	284,656	148,627
Investments in privately held entities that do not report NAV
Schedule of Investments
Investments in privately held entities that do not report NAV, upward price adjustment	10,800
Investments in privately held entities that do not report NAV, downward price adjustment	(553)
Summary of Investment [Abstract]
Investment at fair value, cost		265,116
Investments in privately held entities that do not report fair value, book value		$ 265,116
Investments in privately held entities that do not report NAV \| Entities with observable price change since January 1, 2018
Summary of Investment [Abstract]
Investment at fair value, cost	12,811
Cumulative unrealized gains (losses) on investments	10,289
Investments in privately held entities that do not report fair value, book value	23,100
Investments in privately held entities that do not report NAV \| Entities without observable price changes since January 1, 2018
Summary of Investment [Abstract]
Investment at fair value, cost	284,381
Cumulative unrealized gains (losses) on investments	0
Investments in privately held entities that do not report fair value, book value	$ 284,381

Investments Investment Income (

Investments Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net Investment Income
Investment income, unrealized gains (losses)	$ 5,067		$ 77,296
Investment income, realized gains (losses)	7,463		20,795
Investment income	12,530	$ 0	98,091	$ 0
Unrealized losses on equity securities		$ (4,000)
Unrealized gains on equity securities				$ 6,400
Investments in publicly traded companies
Net Investment Income
Investment income, unrealized gains (losses)	1,138		52,026
Investment income, realized gains (losses)	0		0
Investment income	1,138		52,026
Investments in privately held entities that report NAV
Net Investment Income
Investment income, unrealized gains (losses)	4,683		19,770
Investment income, realized gains (losses)	0		0
Investment income	4,683		19,770
Investments in privately held entities that do not report NAV
Net Investment Income
Investment income, unrealized gains (losses)	(754)		10,289
Investment income, realized gains (losses)	0		0
Investment income	(754)		10,289
Total investments at fair value, held at period end
Net Investment Income
Investment income, unrealized gains (losses)	5,067		82,085
Investment income, realized gains (losses)	0		0
Investment income	5,067		82,085
Investment disposed and recognized during the period
Net Investment Income
Investment income, unrealized gains (losses)	0		0
Investment income, realized gains (losses)	7,463		16,006
Investment income	7,463		16,006
Investment disposed and previously recognized
Net Investment Income
Investment income, unrealized gains (losses)	0		(4,789)
Investment income, realized gains (losses)	0		4,789
Investment income	0		0
Total investment disposition during the period
Net Investment Income
Investment income, unrealized gains (losses)	0		(4,789)
Investment income, realized gains (losses)	7,463		20,795
Investment income	$ 7,463		$ 16,006

Other assets Other assets (Deta

Other assets Other assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Acquired below-market ground leases	$ 17,624	$ 12,684
Acquired in-place leases	134,809	64,979
Deferred compensation plan	19,400	15,534
Deferred financing costs – $1.65 billion unsecured senior line of credit	8,667	10,525
Deposits	5,275	10,576
Furniture, fixtures, and equipment	11,538	11,070
Interest rate hedge assets	5,991	5,260
Net investment in direct financing lease	38,763	38,382
Notes receivable	572	614
Prepaid expenses	13,097	10,972
Property, plant, and equipment	56,841	32,073
Other assets	21,180	15,784
Total	$ 333,757	$ 228,453

Other assets Net investment in

Other assets Net investment in direct financing lease (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Gross investment in direct financing lease	$ 262,918	$ 263,719
Less: unearned income	(224,155)	(225,337)
Net investment in direct financing lease	$ 38,763	$ 38,382

Other assets Direct financing l

Other assets Direct financing lease - future minimum lease payments (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Capital Leased Assets
Total	$ 262,918	$ 263,719
Direct financing lease
Capital Leased Assets
2,018	806
2,019	1,655
2,020	1,705
2,021	1,756
2,022	1,809
Thereafter	255,187
Total	$ 262,918

Fair value measurements Assets

Fair value measurements Assets and Liabilities on Recurring Basis (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)transfer	Dec. 31, 2017USD ($)
Assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy
Transfers in Fair Value Hierarchy \| transfer	0
Assets:
Interest rate hedge assets	$ 5,991	$ 5,260
Liabilities:
Interest rate hedge liabilities	0	103
Fair value measured on recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Interest rate hedge assets	0	0
Liabilities:
Interest rate hedge liabilities		0
Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2)
Assets:
Interest rate hedge assets	5,991	5,260
Liabilities:
Interest rate hedge liabilities		103
Fair value measured on recurring basis \| Significant Unobservable Inputs (Level 3)
Assets:
Interest rate hedge assets	0	0
Liabilities:
Interest rate hedge liabilities		0
Fair Value \| Fair value measured on recurring basis
Assets:
Interest rate hedge assets	5,991	5,260
Liabilities:
Interest rate hedge liabilities		103
Investments in publicly traded companies
Assets:
Investments in publicly traded companies	198,616	109,511
Investments in publicly traded companies \| Fair value measured on recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in publicly traded companies	198,616	109,511
Investments in publicly traded companies \| Fair value measured on recurring basis \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in publicly traded companies	0	0
Investments in publicly traded companies \| Fair value measured on recurring basis \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in publicly traded companies	0	0
Investments in publicly traded companies \| Fair Value \| Fair value measured on recurring basis
Assets:
Investments in publicly traded companies	$ 198,616	$ 109,511

Fair value measurements Book an

Fair value measurements Book and Fair Values (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Summary of investments in privately held entities that report NAV, secured notes payable, unsecured senior line of credit, and unsecured term loans
Secured notes payable	$ 776,260	$ 771,061
Unsecured senior notes payable	4,289,521	3,395,804
Unsecured senior line of credit	0	50,000
Unsecured senior bank term loans	548,324	547,942
Book Value
Summary of investments in privately held entities that report NAV, secured notes payable, unsecured senior line of credit, and unsecured term loans
Secured notes payable	776,260	771,061
Unsecured senior notes payable	4,289,521	3,395,804
Unsecured senior line of credit	0	50,000
Unsecured senior bank term loans	548,324	547,942
Fair Value
Summary of investments in privately held entities that report NAV, secured notes payable, unsecured senior line of credit, and unsecured term loans
Secured notes payable	774,955	776,222
Unsecured senior notes payable	4,300,275	3,529,713
Unsecured senior line of credit	0	49,986
Unsecured senior bank term loans	550,280	549,361
Investments in privately held entities that report NAV
Summary of investments in privately held entities that report NAV, secured notes payable, unsecured senior line of credit, and unsecured term loans
Investments in privately held entities that report NAV	284,656	$ 148,627
Investments in privately held entities that report NAV \| Book Value
Summary of investments in privately held entities that report NAV, secured notes payable, unsecured senior line of credit, and unsecured term loans
Investments in privately held entities that report NAV	284,656
Investments in privately held entities that report NAV \| Fair Value
Summary of investments in privately held entities that report NAV, secured notes payable, unsecured senior line of credit, and unsecured term loans
Investments in privately held entities that report NAV	$ 284,656

Secured and unsecured senior 54

Secured and unsecured senior debt Summary of secured and unsecured debt (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Debt Instrument
Long-term Debt	$ 5,329,742
Long-term Debt, Percentage Bearing Variable Interest, Amount, Net	284,363
Total Consolidated	$ 5,614,105
Percentage of Total	100.00%
Weighted-Average Interest Rate at End of Period	4.01%
Weighted Average Remaining Terms (in years)	5 years 9 months 18 days
Percentage of fixed rate/hedged total debt	95.00%
Percentage of unhedged floating rate total debt	5.00%
Secured notes payable
Debt Instrument
Long-term Debt	$ 491,897
Long-term Debt, Percentage Bearing Variable Interest, Amount, Net	284,363
Total Consolidated	$ 776,260
Percentage of Total	13.80%
Weighted-Average Interest Rate at End of Period	4.28%
Weighted Average Remaining Terms (in years)	2 years 9 months 18 days
Unsecured senior notes payable
Debt Instrument
Long-term Debt	$ 4,289,521
Long-term Debt, Percentage Bearing Variable Interest, Amount, Net	0
Total Consolidated	$ 4,289,521
Percentage of Total	76.40%
Weighted-Average Interest Rate at End of Period	4.15%
Weighted Average Remaining Terms (in years)	6 years 10 months 24 days
$1.65 billion unsecured senior line of credit
Debt Instrument
Long-term Debt	$ 0
Long-term Debt, Percentage Bearing Variable Interest, Amount, Net	0
Total Consolidated	$ 0
Percentage of Total	0.00%
Weighted-Average Interest Rate at End of Period	0.00%
Weighted Average Remaining Terms (in years)	3 years 3 months 18 days
2019 Unsecured Senior Bank Term Loan
Debt Instrument
Long-term Debt	$ 199,620
Long-term Debt, Percentage Bearing Variable Interest, Amount, Net	0
Total Consolidated	$ 199,620
Percentage of Total	3.60%
Weighted-Average Interest Rate at End of Period	2.75%
Weighted Average Remaining Terms (in years)	6 months
2021 Unsecured Senior Bank Term Loan
Debt Instrument
Long-term Debt	$ 348,704
Long-term Debt, Percentage Bearing Variable Interest, Amount, Net	0
Total Consolidated	$ 348,704
Percentage of Total	6.20%
Weighted-Average Interest Rate at End of Period	2.41%
Weighted Average Remaining Terms (in years)	2 years 6 months

Secured and unsecured senior 55

Secured and unsecured senior debt Detail of secured and unsecured debt (Details)	1 Months Ended	3 Months Ended			6 Months Ended
	Jul. 31, 2018USD ($)	Jun. 30, 2018USD ($)Extension_Option	Dec. 31, 2017USD ($)	Mar. 31, 2017USD ($)	Jun. 30, 2018USD ($)Extension_Option	Jun. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument
Effective rate (as a percent)		4.01%			4.01%
Repayments of Secured Debt					$ 3,162,000	$ 1,677,000
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 5,635,425,000			5,635,425,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(21,320,000)			(21,320,000)
Total Consolidated		$ 5,614,105,000			$ 5,614,105,000
Secured notes payable
Debt Instrument
Stated interest rate (as a percent)		4.60%			4.60%
Effective rate (as a percent)		4.28%			4.28%
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 760,425,000			$ 760,425,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		15,835,000			15,835,000
Total Consolidated		$ 776,260,000			$ 776,260,000
Secured Notes Payable Maturing on 4/1/20
Debt Instrument
Stated interest rate (as a percent)		7.75%			7.75%
Effective rate (as a percent)		8.15%			8.15%
Maturity Date					Apr. 1, 2020
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 107,499,000			$ 107,499,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(585,000)			(585,000)
Total Consolidated		$ 106,914,000			$ 106,914,000
Secured Notes Payable Maturing on 1/1/23
Debt Instrument
Stated interest rate (as a percent)		4.66%			4.66%
Effective rate (as a percent)		4.90%			4.90%
Maturity Date					Jan. 1, 2023
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 34,175,000			$ 34,175,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(296,000)			(296,000)
Total Consolidated		$ 33,879,000			$ 33,879,000
Secured Notes Payable Maturing on 3/10/23
Debt Instrument
Stated interest rate (as a percent)		3.93%			3.93%
Effective rate (as a percent)		3.19%			3.19%
Maturity Date					Mar. 10, 2023
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 81,640,000			$ 81,640,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		2,566,000			2,566,000
Total Consolidated		$ 84,206,000			$ 84,206,000
Secured Notes Payable Maturing on 2/6/24
Debt Instrument
Stated interest rate (as a percent)		4.82%			4.82%
Effective rate (as a percent)		3.40%			3.40%
Maturity Date					Feb. 6, 2024
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 201,986,000			$ 201,986,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		14,848,000			14,848,000
Total Consolidated		$ 216,834,000			$ 216,834,000
Secured Notes Payable Maturing on 7/1/36
Debt Instrument
Stated interest rate (as a percent)		6.50%			6.50%
Effective rate (as a percent)		6.50%			6.50%
Maturity Date					Jul. 1, 2036
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 762,000			$ 762,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		0			0
Total Consolidated		$ 762,000			$ 762,000
Unsecured Debt
Debt Instrument
Effective rate (as a percent)		3.96%			3.96%
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 4,875,000,000			$ 4,875,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(37,155,000)			(37,155,000)
Total Consolidated		$ 4,837,845,000			$ 4,837,845,000
2019 Unsecured Senior Bank Term Loan
Debt Instrument
Effective rate (as a percent)		2.75%			2.75%
Maturity Date					Jan. 3, 2019
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 200,000,000			$ 200,000,000	$ 200,000,000	$ 400,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(380,000)			(380,000)
Total Consolidated		$ 199,620,000			$ 199,620,000
2021 Unsecured Senior Bank Term Loan
Debt Instrument
Effective rate (as a percent)		2.41%			2.41%
Maturity Date					Jan. 15, 2021
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 350,000,000			$ 350,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(1,296,000)			(1,296,000)
Total Consolidated		$ 348,704,000			$ 348,704,000
$1.65 billion unsecured senior line of credit
Debt Instrument
Effective rate (as a percent)		0.00%			0.00%
Maturity Date					Oct. 29, 2021
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 0			$ 0
Unamortized (Deferred Financing Cost), (Discount)/Premium		0			0
Total Consolidated		$ 0			$ 0
2.75% Unsecured Senior Notes Payable
Debt Instrument
Stated interest rate (as a percent)		2.75%			2.75%
Effective rate (as a percent)		2.96%			2.96%
Maturity Date					Jan. 15, 2020
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 400,000,000			$ 400,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(1,237,000)			(1,237,000)
Total Consolidated		$ 398,763,000			$ 398,763,000
4.60% Unsecured Senior Notes Payable
Debt Instrument
Stated interest rate (as a percent)		4.60%			4.60%
Effective rate (as a percent)		4.75%			4.75%
Maturity Date					Apr. 1, 2022
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 550,000,000			$ 550,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(2,438,000)			(2,438,000)
Total Consolidated		$ 547,562,000			$ 547,562,000
3.90% Unsecured Senior Notes Payable
Debt Instrument
Stated interest rate (as a percent)		3.90%			3.90%
Effective rate (as a percent)		4.04%			4.04%
Maturity Date					Jun. 15, 2023
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 500,000,000			$ 500,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(2,945,000)			(2,945,000)
Total Consolidated		$ 497,055,000			$ 497,055,000
4.00% Unsecured Senior Note Payable
Debt Instrument
Stated interest rate (as a percent)		4.00%			4.00%
Effective rate (as a percent)		4.18%			4.18%
Maturity Date		Jan. 15, 2024			Jan. 15, 2024
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 450,000,000			$ 450,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(4,050,000)			(4,050,000)
Total Consolidated		$ 445,950,000			$ 445,950,000
3.45% Unsecured Senior Notes Payable
Debt Instrument
Stated interest rate (as a percent)		3.45%	3.45%		3.45%
Effective rate (as a percent)		3.62%			3.62%
Maturity Date			Apr. 30, 2025		Apr. 30, 2025
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 600,000,000	$ 600,000,000		$ 600,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(5,954,000)			(5,954,000)
Total Consolidated		$ 594,046,000			$ 594,046,000
4.30% Unsecured Senior Notes Payable
Debt Instrument
Stated interest rate (as a percent)		4.30%			4.30%
Effective rate (as a percent)		4.50%			4.50%
Maturity Date					Jan. 15, 2026
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 300,000,000			$ 300,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(3,648,000)			(3,648,000)
Total Consolidated		$ 296,352,000			$ 296,352,000
3.95% Unsecured Senior Notes Payable Due in 2027
Debt Instrument
Stated interest rate (as a percent)		3.95%			3.95%
Effective rate (as a percent)		4.13%			4.13%
Maturity Date					Jan. 15, 2027
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 350,000,000			$ 350,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(4,278,000)			(4,278,000)
Total Consolidated		$ 345,722,000			$ 345,722,000
3.95% Unsecured Senior Notes Payable Due in 2028
Debt Instrument
Stated interest rate (as a percent)		3.95%		3.95%	3.95%
Effective rate (as a percent)		4.07%			4.07%
Maturity Date				Jan. 15, 2028	Jan. 15, 2028
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 425,000,000		$ 425,000,000	$ 425,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(4,024,000)			(4,024,000)
Total Consolidated		$ 420,976,000			$ 420,976,000
4.50% Unsecured Senior Notes Payable
Debt Instrument
Stated interest rate (as a percent)		4.50%			4.50%
Effective rate (as a percent)		4.60%			4.60%
Maturity Date					Jul. 30, 2029
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 300,000,000			$ 300,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(2,452,000)			(2,452,000)
Total Consolidated		$ 297,548,000			$ 297,548,000
4.70% Unsecured Senior Notes Payable
Debt Instrument
Stated interest rate (as a percent)		4.70%			4.70%
Effective rate (as a percent)		4.81%			4.81%
Maturity Date		Jul. 1, 2030			Jul. 1, 2030
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 450,000,000			$ 450,000,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(4,453,000)			(4,453,000)
Total Consolidated		$ 445,547,000			$ 445,547,000
London Interbank Offered Rate (LIBOR) \| 2019 Unsecured Senior Bank Term Loan
Debt Instrument
Applicable margin (as a percent)					1.20%
London Interbank Offered Rate (LIBOR) \| 2021 Unsecured Senior Bank Term Loan
Debt Instrument
Applicable margin (as a percent)					1.10%
London Interbank Offered Rate (LIBOR) \| $1.65 billion unsecured senior line of credit
Debt Instrument
Applicable margin (as a percent)					1.00%
Secured Notes Payable Maturing on 1/28/19 \| Construction Loans
Debt Instrument
Effective rate (as a percent)		3.82%			3.82%
Maturity Date					Jan. 28, 2019
Total aggregate commitment		$ 350,000,000			$ 350,000,000
Debt Instrument, Number of One-Year Maturity Date Extension Option \| Extension_Option		2			2
Debt Instrument, Extended Maturity Period					1 year
Future principal payments due on secured and unsecured debt
Outstanding Balance		$ 334,363,000			$ 334,363,000
Unamortized (Deferred Financing Cost), (Discount)/Premium		(698,000)			(698,000)
Total Consolidated		$ 333,665,000			$ 333,665,000
Secured Notes Payable Maturing on 1/28/19 \| London Interbank Offered Rate (LIBOR) \| Construction Loans
Debt Instrument
Applicable margin (as a percent)					1.50%
Subsequent Event \| Secured Notes Payable Maturing on 1/28/19 \| Construction Loans
Debt Instrument
Total aggregate commitment	$ 200,000,000
Repayments of Secured Debt	$ 150,000,000

Secured and unsecured senior 56

Secured and unsecured senior debt Unsecured senior notes payable (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Debt Instrument
Outstanding Balance	$ 5,635,425			$ 5,635,425
Proceeds from issuance of unsecured senior notes payable				899,321	$ 424,384
Repayments of Secured Debt				3,162	$ 1,677
4.00% and 4.70% Unsecured Senior Notes Payable
Debt Instrument
Outstanding Balance	900,000			900,000
Proceeds from issuance of unsecured senior notes payable	891,400
4.00% Unsecured Senior Note Payable
Debt Instrument
Outstanding Balance	$ 450,000			$ 450,000
Maturity Date	Jan. 15, 2024			Jan. 15, 2024
Stated interest rate (as a percent)	4.00%			4.00%
4.70% Unsecured Senior Notes Payable
Debt Instrument
Outstanding Balance	$ 450,000			$ 450,000
Maturity Date	Jul. 1, 2030			Jul. 1, 2030
Stated interest rate (as a percent)	4.70%			4.70%
3.45% Unsecured Senior Notes Payable
Debt Instrument
Outstanding Balance	$ 600,000	$ 600,000		$ 600,000
Maturity Date		Apr. 30, 2025		Apr. 30, 2025
Stated interest rate (as a percent)	3.45%	3.45%		3.45%
Proceeds from issuance of unsecured senior notes payable		$ 593,500
3.95% Unsecured Senior Notes Payable Due in 2028
Debt Instrument
Outstanding Balance	$ 425,000		$ 425,000	$ 425,000
Maturity Date			Jan. 15, 2028	Jan. 15, 2028
Stated interest rate (as a percent)	3.95%		3.95%	3.95%
Proceeds from issuance of unsecured senior notes payable			$ 420,500
Secured notes payable
Debt Instrument
Outstanding Balance	$ 760,425			$ 760,425
Stated interest rate (as a percent)	4.60%			4.60%
Two secured construction loans \| Secured notes payable
Debt Instrument
Repayments of Secured Debt		$ 389,800

Secured and unsecured senior 57

Secured and unsecured senior debt Repayment of unsecured senior bank term loans and secured notes payable (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2016
Debt Instrument
Repayments of Secured Debt				$ 3,162,000	$ 1,677,000
Long-term Debt, Gross		$ 5,635,425,000		5,635,425,000
Loss on early extinguishment of debt		0	$ 0	0	670,000
2019 Unsecured Senior Bank Term Loan
Debt Instrument
Repayments of Debt					200,000,000
Long-term Debt, Gross		200,000,000	$ 200,000,000	200,000,000	200,000,000	$ 400,000,000
Loss on early extinguishment of debt					$ 670,000
Secured Notes Payable Maturing on 1/28/19 \| Construction Loans
Debt Instrument
Long-term Debt, Gross		334,363,000		334,363,000
Total aggregate commitment		$ 350,000,000		$ 350,000,000
Subsequent Event \| Secured Notes Payable Maturing on 1/28/19 \| Construction Loans
Debt Instrument
Repayments of Secured Debt	$ 150,000,000
Total aggregate commitment	200,000,000
Loss on early extinguishment of debt	$ (299,000)

Secured and unsecured senior 58

Secured and unsecured senior debt Schedule of interest expense incurred (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest expense incurred
Gross interest	$ 53,624	$ 46,817	$ 103,899	$ 89,765
Capitalized interest	(15,527)	(15,069)	(28,887)	(28,233)
Interest expense	$ 38,097	$ 31,748	$ 75,012	$ 61,532

Interest rate hedge agreement59

Interest rate hedge agreements Interest rate hedge agreements (Details) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
The percentage of effectiveness of interest rate swap agreements	0.00%	100.00%
Interest rate swap hedge ineffectiveness recognized in earnings	$ 0	$ 0
Cash flow hedge loss to be reclassified within twelve month	5,300,000
Collateral obligation requirements	0
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 0

Interest rate hedge agreement60

Interest rate hedge agreements Outstanding interest rate swap (Details) $ in Thousands	Jun. 30, 2018USD ($)contract
Interest rate hedge agreements
Fair Values	$ 5,991
Notional Amount in Effect as of 6/30/18	600,000
Notional Amount in Effect as of 12/31/18	600,000
Notional Amount in Effect as of 12/31/19	$ 100,000
1.16% Interest rate swap, effective March 29, 2018
Interest rate hedge agreements
Number of Contracts \| contract	8
Interest Pay Rate (as a percent)	1.16%
Fair Values	$ 5,142
Notional Amount in Effect as of 6/30/18	600,000
Notional Amount in Effect as of 12/31/18	600,000
Notional Amount in Effect as of 12/31/19	$ 0
1.89% Interest rate swap, effective March 29, 2019
Interest rate hedge agreements
Number of Contracts \| contract	1
Interest Pay Rate (as a percent)	1.89%
Fair Values	$ 849
Notional Amount in Effect as of 6/30/18	0
Notional Amount in Effect as of 12/31/18	0
Notional Amount in Effect as of 12/31/19	$ 100,000

Accounts payable, accrued exp61

Accounts payable, accrued expenses, and tenant security deposits (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Accounts payable, accrued expenses, and tenant security deposits [Abstract]
Accounts payable and accrued expenses	$ 394,435	$ 349,884
Acquired below market leases	123,402	88,184
Asset Retirement Obligation	10,519	7,397
Deferred Rent Liability	28,367	27,953
Interest rate hedge liabilities	0	103
Prepaid Rent and Tenant Security Deposits	248,543	248,924
Other Accounts Payable and Accrued Liabilities	44,008	41,387
Accounts Payable and Accrued Liabilities	$ 849,274	$ 763,832

Earnings per share Earnings per

Earnings per share Earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended					6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Class of Stock
Shares of common stock authorized	200,000,000					200,000,000
Proceeds from the issuance of common stock						$ 400,207	$ 459,607
Earnings Per Share Reconciliation
Net income (loss)	$ 60,547			$ 41,496		202,065	89,051
Net income attributable to noncontrolling interests	(5,817)			(7,275)		(11,705)	(13,119)
Dividends on preferred stock	(1,302)			(1,278)		(2,604)	(5,062)
Preferred stock redemption charge	0			0		0	(11,279)
Net income attributable to unvested restricted stock awards	(1,412)			(1,313)		(2,765)	(2,300)
Numerator for basic and diluted EPS – net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	$ 52,016			$ 31,630		$ 184,991	$ 57,291
Denominator for basic EPS – weighted-average shares of common stock outstanding	101,881,000			90,215,000		100,878,000	89,186,000
Dilutive effect of forward equity sales agreements	355,000			530,000		313,000	293,000
Denominator for diluted EPS – weighted-average shares of common stock outstanding	102,236,000			90,745,000		101,191,000	89,479,000
Earnings per share attributable to Alexandria Real Estate Equities, Inc.'s common stockholders - basic and diluted:
Earnings per share – basic (USD per share)	$ 0.51			$ 0.35		$ 1.83	$ 0.64
Earnings per shares - diluted (USD per share)	$ 0.51			$ 0.35		$ 1.83	$ 0.64
Series D Convertible Preferred Stock
Class of Stock
Preferred stock, dividend rate (as a percent)						7.00%
January 2018 forward equity sales agreement
Class of Stock
Sale of Stock, Price Per Share		$ 123.50
Common stock, shares settled		843,600
Proceeds from the issuance of common stock		$ 100,200
Common stock value available for future issuance	$ 709,900					$ 709,900
January 2018 forward equity sales agreement \| Total Shares
Class of Stock
Shares of common stock authorized		6,900,000
March 2017 forward equity sales agreement
Class of Stock
Sale of Stock, Price Per Share					$ 108.55
March 2017 forward equity sales agreement \| Total Shares
Class of Stock
Shares of common stock authorized					6,900,000
March 2017 forward equity sales agreement \| Initial issuance shares
Class of Stock
Shares of common stock authorized					2,100,000
Proceeds from the issuance of common stock					$ 217,800
March 2017 forward equity sales agreement \| Incremental Shares
Class of Stock
Shares of common stock authorized					4,800,000
Proceeds from the issuance of common stock			$ 484,600

Stockholders' equity (Details)

Stockholders' equity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended		10 Months Ended	12 Months Ended
	Jul. 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Dec. 31, 2017	Aug. 31, 2017
ATM program
Shares of common stock authorized		200,000,000		200,000,000		200,000,000
Proceeds from the issuance of common stock				$ 400,207	$ 459,607
Preferred stock
Preferred stock redemption charge		$ 0	$ 0	0	$ 11,279
Dividends declared on common stock		$ 97,600		$ 189,571
Dividends declared per share of common stock (USD per share)		$ 0.93	$ 0.86	$ 1.83	$ 1.69
Dividends declared on preferred stock		$ 1,300		$ 2,604
Dividends declared on preferred stock (USD per share)		$ 0.4375		$ 0.875
Preferred stock, shares authorized		100,000,000		100,000,000		100,000,000
Shares of preferred stock issued and outstanding		2,975,432		2,975,432		2,975,432
Shares of common stock issued and outstanding		103,346,117		103,346,117		103,346,117
Number of "excess stock" authorized (in shares)				200,000,000
Number of excess stock authorized issued and outstanding (in shares)		0		0		0
7.00% Series D Cumulative Convertible Preferred Stock
Preferred stock
Preferred Stock, Shares Outstanding		2,975,432	2,975,432	2,975,432	2,975,432	2,975,432
Number of shares repurchased/redeemed					501,115
Aggregate price on repurchase of Series D preferred stock					$ 17,900
Aggregate price per share on repurchase of Series D preferred stock					$ 35.79
Preferred stock redemption charge					$ 5,800
Repurchase/redemption of preferred stock					391
6.45% Series E Cumulative Redeemable Preferred Stock
Preferred stock
Number of shares repurchased/redeemed			5,200,000
Preferred stock redemption charge			$ 5,500
Preferred Stock, Redemption Date			Apr. 14, 2017
Preferred stock redemption liability			$ 130,000		$ 130,000
Preferred Stock, Redemption Price Per Share			$ 25		$ 25
ATM Common Stock Offering Program, Established August 2017
ATM program
Shares of common stock authorized								750,000,000
Issuances of common stock shares				2,456,037		5,229,355	2,773,318
Gross proceeds from issuance of common stock				$ 305,700		$ 642,300	$ 336,600
Shares Issued, Average Price Per Share				$ 124.46		$ 122.82
Proceeds from the issuance of common stock				$ 300,800		$ 632,000
Common stock value available for future issuance		$ 107,700		$ 107,700		$ 107,700
Subsequent Event \| ATM Common Stock Offering Program, Established August 2017
ATM program
Issuances of common stock shares	703,625
Gross proceeds from issuance of common stock	$ 90,000
Shares Issued, Average Price Per Share	$ 127.91
Proceeds from the issuance of common stock	$ 88,700
Common stock value available for future issuance	$ 17,700

Stockholders' equity Accumulate

Stockholders' equity Accumulated other comprehensive loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Balance as of December 31, 2017			$ 50,024
Unrealized holding gains (losses) arising during the period	$ 0	$ (4,025)	0	$ 6,396
Unrealized interest rate hedge gains (losses) arising during the period	661	(550)	2,643	667
Unrealized foreign currency translation (losses) gains arising during the period	(3,243)	2,744	(3,572)	3,756
Other comprehensive income (loss) before reclassifications			(929)
Reclassification adjustment for losses included in net income	0	2,349	0	2,482
Reclassification adjustment for amortization of interest (income) expense included in net income	(1,131)	707	(1,809)	1,612
Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation	0	$ 0	0	$ 2,421
Amounts reclassified from other comprehensive income to net income			(1,809)
Reclassification of cumulative net unrealized gains on non-real estate investments			90,750
Net other comprehensive income			(2,738)
Balance as of June 30, 2018	(2,485)		(2,485)
Available-for- Sale Equity Securities
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Balance as of December 31, 2017			49,771
Reclassification of cumulative net unrealized gains on non-real estate investments			(49,771)
Net other comprehensive income			0
Balance as of June 30, 2018	0		0
Interest Rate Hedge Agreements
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Balance as of December 31, 2017			5,157
Reclassification of cumulative net unrealized gains on non-real estate investments			0
Net other comprehensive income			834
Balance as of June 30, 2018	5,991		5,991
Foreign Currency Translation
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Balance as of December 31, 2017			(4,904)
Reclassification of cumulative net unrealized gains on non-real estate investments			0
Net other comprehensive income			(3,572)
Balance as of June 30, 2018	$ (8,476)		(8,476)
Accumulated Other Comprehensive Income
Increase (Decrease) Accumulated Other Comprehensive Income (Loss) Net of Tax [Roll Forward]
Reclassification of cumulative net unrealized gains on non-real estate investments			$ (49,771)

Noncontrolling interests (Detai

Noncontrolling interests (Details) $ in Thousands	6 Months Ended
Noncontrolling interests (Details) $ in Thousands	Jun. 30, 2018USD ($)property	Jun. 30, 2017USD ($)
Noncontrolling interests
Payments to Noncontrolling Interests	$ 19,841	$ 10,791
Noncontrolling Interests
Noncontrolling interests
Number of real estate properties subject to ownership from noncontrolling interest \| property	8
Payments to Noncontrolling Interests	$ (18,400)	$ 10,791

Assets classified as held for66

Assets classified as held for sale (Details) $ in Thousands	Jun. 30, 2018USD ($)ft²	Dec. 31, 2017USD ($)
Discontinued Operations and Disposal Groups [Abstract]
Assets held for sale - area of real estate \| ft²	389,018
Net assets held for sale [Abstract]
Total assets	$ 41,934	$ 31,578
Total liabilities	(1,789)	(1,809)
Total accumulated other comprehensive income	(436)	(1,021)
Net assets classified as held for sale	$ 39,709	$ 28,748

Condensed consolidating finan67

Condensed consolidating financial information Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Assets
Investments in real estate	$ 11,190,771	$ 10,298,019
Investments in and advances to affiliates	192,972	110,618
Cash and cash equivalents	287,029	254,381
Restricted cash	34,812	22,805
Tenant receivables	8,704	10,262
Deferred rent	490,428	434,731
Deferred leasing costs	232,964	221,430
Investments	790,753	523,254
Investments in and advances to affiliates	0	0
Other assets	333,757	228,453
Total assets	13,562,190	12,103,953
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	776,260	771,061
Unsecured senior notes payable	4,289,521	3,395,804
Unsecured senior line of credit	0	50,000
Unsecured senior bank term loans	548,324	547,942
Accounts payable, accrued expenses, and tenant security deposits	849,274	763,832
Dividends payable	98,676	92,145
Total liabilities	6,562,055	5,620,784
Redeemable noncontrolling interests	10,861	11,509
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	6,460,461	5,949,666
Noncontrolling interests	528,813	521,994
Total equity	6,989,274	6,471,660
Total liabilities, noncontrolling interests, and equity	13,562,190	12,103,953
Eliminations
Assets
Investments in real estate	0	0
Investments in and advances to affiliates	0	0
Cash and cash equivalents	0	0
Restricted cash	0	0
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing costs	0	0
Investments	0	0
Investments in and advances to affiliates	(21,524,963)	(19,164,705)
Other assets	0	0
Total assets	(21,524,963)	(19,164,705)
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 Real Estate Equities, Inc.’s stockholders’ equity	(21,524,963)	(19,164,705)
Noncontrolling interests	0	0
Total equity	(21,524,963)	(19,164,705)
Total liabilities, noncontrolling interests, and equity	(21,524,963)	(19,164,705)
Alexandria Real Estate Equities, Inc. (Issuer)
Assets
Investments in real estate	0	0
Investments in and advances to affiliates	0	0
Cash and cash equivalents	181,342	130,364
Restricted cash	155	152
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing costs	0	0
Investments	0	0
Investments in and advances to affiliates	11,253,161	9,949,861
Other assets	51,551	45,108
Total assets	11,486,209	10,125,485
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	0	0
Unsecured senior notes payable	4,289,521	3,395,804
Unsecured senior line of credit	0	50,000
Unsecured senior bank term loans	548,324	547,942
Accounts payable, accrued expenses, and tenant security deposits	89,227	89,928
Dividends payable	98,676	92,145
Total liabilities	5,025,748	4,175,819
Redeemable noncontrolling interests	0	0
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	6,460,461	5,949,666
Noncontrolling interests	0	0
Total equity	6,460,461	5,949,666
Total liabilities, noncontrolling interests, and equity	11,486,209	10,125,485
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Assets
Investments in real estate	0	0
Investments in and advances to affiliates	0	0
Cash and cash equivalents	0	9
Restricted cash	0	0
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing costs	0	0
Investments	1,690	1,655
Investments in and advances to affiliates	10,066,773	9,030,994
Other assets	0	0
Total assets	10,068,463	9,032,658
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 Real Estate Equities, Inc.’s stockholders’ equity	10,068,463	9,032,658
Noncontrolling interests	0	0
Total equity	10,068,463	9,032,658
Total liabilities, noncontrolling interests, and equity	10,068,463	9,032,658
Combined Non- Guarantor Subsidiaries
Assets
Investments in real estate	11,190,771	10,298,019
Investments in and advances to affiliates	192,972	110,618
Cash and cash equivalents	105,687	124,008
Restricted cash	34,657	22,653
Tenant receivables	8,704	10,262
Deferred rent	490,428	434,731
Deferred leasing costs	232,964	221,430
Investments	789,063	521,599
Investments in and advances to affiliates	205,029	183,850
Other assets	282,206	183,345
Total assets	13,532,481	12,110,515
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	776,260	771,061
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	760,047	673,904
Dividends payable	0	0
Total liabilities	1,536,307	1,444,965
Redeemable noncontrolling interests	10,861	11,509
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	11,456,500	10,132,047
Noncontrolling interests	528,813	521,994
Total equity	11,985,313	10,654,041
Total liabilities, noncontrolling interests, and equity	$ 13,532,481	$ 12,110,515

Condensed consolidating finan68

Condensed consolidating financial information Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Condensed Income Statements
Revenue	$ 325,034	$ 273,059	$ 645,173	$ 543,936
Expenses:
Rental operations	91,908	76,980	183,679	154,067
General and administrative	22,939	19,234	45,360	38,463
Interest	38,097	31,748	75,012	61,532
Depreciation and amortization	118,852	104,098	233,071	201,281
Impairment of real estate	6,311	203	6,311	203
Loss on early extinguishment of debt	0	0	0	670
Total expenses	278,107	232,263	543,433	456,216
Equity in earnings of unconsolidated real estate joint ventures	1,090	589	2,234	950
Equity in earnings of affiliates	0	0	0	0
Investment income	12,530	0	98,091	0
Gain (loss) on sale of real estate - rental properties	0	0	0	270
Gain (loss) on sale of real estate - land parcels	0	111	0	111
Net income	60,547	41,496	202,065	89,051
Net income attributable to noncontrolling interests	(5,817)	(7,275)	(11,705)	(13,119)
Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	54,730	34,221	190,360	75,932
Dividends on preferred stock	(1,302)	(1,278)	(2,604)	(5,062)
Preferred stock redemption charge	0	0	0	(11,279)
Net income attributable to unvested restricted stock awards	(1,412)	(1,313)	(2,765)	(2,300)
Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	52,016	31,630	184,991	57,291
Eliminations
Condensed Income Statements
Revenue	(5,837)	(4,960)	(10,402)	(9,597)
Expenses:
Rental operations	0	0	0	0
General and administrative	(5,837)	(4,960)	(10,402)	(9,597)
Interest	0	0	0	0
Depreciation and amortization	0	0	0	0
Impairment of real estate	0	0	0	0
Loss on early extinguishment of debt			0	0
Total expenses	(5,837)	(4,960)	(10,402)	(9,597)
Equity in earnings of unconsolidated real estate joint ventures	0	0	0	0
Equity in earnings of affiliates	(207,290)	(145,034)	(494,294)	(315,985)
Investment income	0		0
Gain (loss) on sale of real estate - rental properties				0
Gain (loss) on sale of real estate - land parcels		0		0
Net income	(207,290)	(145,034)	(494,294)	(315,985)
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	(207,290)	(145,034)	(494,294)	(315,985)
Dividends on preferred stock	0	0	0	0
Preferred stock redemption charge				0
Net income attributable to unvested restricted stock awards	0	0	0	0
Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	(207,290)	(145,034)	(494,294)	(315,985)
Alexandria Real Estate Equities, Inc. (Issuer)
Condensed Income Statements
Revenue	4,965	4,124	9,089	8,107
Expenses:
Rental operations	0	0	0	0
General and administrative	23,001	19,428	44,891	38,674
Interest	32,139	21,831	63,234	48,949
Depreciation and amortization	1,647	1,721	3,324	3,430
Impairment of real estate	0	0	0	0
Loss on early extinguishment of debt			0	670
Total expenses	56,787	42,980	111,449	91,723
Equity in earnings of unconsolidated real estate joint ventures	0	0	0	0
Equity in earnings of affiliates	106,552	73,077	292,720	159,548
Investment income	0		0
Gain (loss) on sale of real estate - rental properties				0
Gain (loss) on sale of real estate - land parcels		0		0
Net income	54,730	34,221	190,360	75,932
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	54,730	34,221	190,360	75,932
Dividends on preferred stock	(1,302)	(1,278)	(2,604)	(5,062)
Preferred stock redemption charge				(11,279)
Net income attributable to unvested restricted stock awards	(1,412)	(1,313)	(2,765)	(2,300)
Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	52,016	31,630	184,991	57,291
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Condensed Income Statements
Revenue	0	1	0	12
Expenses:
Rental operations	0	0	0	0
General and administrative	0	0	0	0
Interest	0	0	0	0
Depreciation and amortization	0	0	0	0
Impairment of real estate	0	0	0	0
Loss on early extinguishment of debt			0	0
Total expenses	0	0	0	0
Equity in earnings of unconsolidated real estate joint ventures	0	0	0	0
Equity in earnings of affiliates	98,795	70,597	197,677	153,445
Investment income	(97)		376
Gain (loss) on sale of real estate - rental properties				0
Gain (loss) on sale of real estate - land parcels		0		0
Net income	98,698	70,598	198,053	153,457
Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	98,698	70,598	198,053	153,457
Dividends on preferred stock	0	0	0	0
Preferred stock redemption charge				0
Net income attributable to unvested restricted stock awards	0	0	0	0
Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	98,698	70,598	198,053	153,457
Combined Non- Guarantor Subsidiaries
Condensed Income Statements
Revenue	325,906	273,894	646,486	545,414
Expenses:
Rental operations	91,908	76,980	183,679	154,067
General and administrative	5,775	4,766	10,871	9,386
Interest	5,958	9,917	11,778	12,583
Depreciation and amortization	117,205	102,377	229,747	197,851
Impairment of real estate	6,311	203	6,311	203
Loss on early extinguishment of debt			0	0
Total expenses	227,157	194,243	442,386	374,090
Equity in earnings of unconsolidated real estate joint ventures	1,090	589	2,234	950
Equity in earnings of affiliates	1,943	1,360	3,897	2,992
Investment income	12,627		97,715
Gain (loss) on sale of real estate - rental properties				270
Gain (loss) on sale of real estate - land parcels		111		111
Net income	114,409	81,711	307,946	175,647
Net income attributable to noncontrolling interests	(5,817)	(7,275)	(11,705)	(13,119)
Net income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	108,592	74,436	296,241	162,528
Dividends on preferred stock	0	0	0	0
Preferred stock redemption charge				0
Net income attributable to unvested restricted stock awards	0	0	0	0
Net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	108,592	74,436	296,241	162,528
Rental revenues
Condensed Income Statements
Revenue	250,635	211,942	495,120	419,135
Rental revenues \| Eliminations
Condensed Income Statements
Revenue	0	0	0	0
Rental revenues \| Alexandria Real Estate Equities, Inc. (Issuer)
Condensed Income Statements
Revenue	0	0	0	0
Rental revenues \| Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Condensed Income Statements
Revenue	0	0	0	0
Rental revenues \| Combined Non- Guarantor Subsidiaries
Condensed Income Statements
Revenue	250,635	211,942	495,120	419,135
Tenant recoveries
Condensed Income Statements
Revenue	72,159	60,470	145,329	121,816
Tenant recoveries \| Eliminations
Condensed Income Statements
Revenue	0	0	0	0
Tenant recoveries \| Alexandria Real Estate Equities, Inc. (Issuer)
Condensed Income Statements
Revenue	0	0	0	0
Tenant recoveries \| Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Condensed Income Statements
Revenue	0	0	0	0
Tenant recoveries \| Combined Non- Guarantor Subsidiaries
Condensed Income Statements
Revenue	72,159	60,470	145,329	121,816
Other income
Condensed Income Statements
Revenue	2,240	647	4,724	2,985
Other income \| Eliminations
Condensed Income Statements
Revenue	(5,837)	(4,960)	(10,402)	(9,597)
Other income \| Alexandria Real Estate Equities, Inc. (Issuer)
Condensed Income Statements
Revenue	4,965	4,124	9,089	8,107
Other income \| Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Condensed Income Statements
Revenue	0	1	0	12
Other income \| Combined Non- Guarantor Subsidiaries
Condensed Income Statements
Revenue	$ 3,112	$ 1,482	$ 6,037	$ 4,463

Condensed consolidating finan69

Condensed consolidating financial information Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Condensed Statement of Comprehensive Income
Net income (loss)	$ 60,547	$ 41,496	$ 202,065	$ 89,051
Unrealized gains (losses) on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period	0	(4,025)	0	6,396
Reclassification adjustment for losses included in net income	0	2,349	0	2,482
Unrealized (losses) gains on public investments, net	0	(1,676)	0	8,878
Unrealized (losses) gains on interest rate hedge agreements:
Unrealized interest rate hedge gains (losses) arising during the period	661	(550)	2,643	667
Reclassification adjustment for amortization of interest (income) expense included in net income	(1,131)	707	(1,809)	1,612
Unrealized (losses) gains on interest rate hedge agreements, net	(470)	157	834	2,279
Unrealized (losses) gains on foreign currency translation:
Unrealized foreign currency translation (losses) gains arising during the period	(3,243)	2,744	(3,572)	3,756
Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation	0	0	0	2,421
Unrealized (losses) gains on foreign currency translation, net	(3,243)	2,744	(3,572)	6,177
Total other comprehensive (loss) income	(3,713)	1,225	(2,738)	17,334
Comprehensive income (loss)	56,834	42,721	199,327	106,385
Less: comprehensive income attributable to noncontrolling interests	(5,817)	(7,283)	(11,705)	(13,131)
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	51,017	35,438	187,622	93,254
Eliminations
Condensed Statement of Comprehensive Income
Net income (loss)	(207,290)	(145,034)	(494,294)	(315,985)
Unrealized gains (losses) on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period		0		0
Reclassification adjustment for losses included in net income		0		0
Unrealized (losses) gains on public investments, net		0		0
Unrealized (losses) gains on interest rate hedge agreements:
Unrealized interest rate hedge gains (losses) arising during the period	0	0	0	0
Reclassification adjustment for amortization of interest (income) expense included in net income	0	0	0	0
Unrealized (losses) gains on interest rate hedge agreements, net	0	0	0	0
Unrealized (losses) gains on foreign currency translation:
Unrealized foreign currency translation (losses) gains arising during the period	0	0	0	0
Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation	0	0	0	0
Unrealized (losses) gains on foreign currency translation, net	0	0	0	0
Total other comprehensive (loss) income	0	0	0	0
Comprehensive income (loss)	(207,290)	(145,034)	(494,294)	(315,985)
Less: comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	(207,290)	(145,034)	(494,294)	(315,985)
Alexandria Real Estate Equities, Inc. (Issuer)
Condensed Statement of Comprehensive Income
Net income (loss)	54,730	34,221	190,360	75,932
Unrealized gains (losses) on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period		0		0
Reclassification adjustment for losses included in net income		0		0
Unrealized (losses) gains on public investments, net		0		0
Unrealized (losses) gains on interest rate hedge agreements:
Unrealized interest rate hedge gains (losses) arising during the period	661	(411)	2,643	888
Reclassification adjustment for amortization of interest (income) expense included in net income	(1,131)	705	(1,809)	1,609
Unrealized (losses) gains on interest rate hedge agreements, net	(470)	294	834	2,497
Unrealized (losses) gains on foreign currency translation:
Unrealized foreign currency translation (losses) gains arising during the period	0	0	0	0
Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation	0	0	0	0
Unrealized (losses) gains on foreign currency translation, net	0	0	0	0
Total other comprehensive (loss) income	(470)	294	834	2,497
Comprehensive income (loss)	54,260	34,515	191,194	78,429
Less: comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	54,260	34,515	191,194	78,429
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Condensed Statement of Comprehensive Income
Net income (loss)	98,698	70,598	198,053	153,457
Unrealized gains (losses) on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period		(1)		(45)
Reclassification adjustment for losses included in net income		1		4
Unrealized (losses) gains on public investments, net		0		(41)
Unrealized (losses) gains on interest rate hedge agreements:
Unrealized interest rate hedge gains (losses) arising during the period	0	0	0	0
Reclassification adjustment for amortization of interest (income) expense included in net income	0	0	0	0
Unrealized (losses) gains on interest rate hedge agreements, net	0	0	0	0
Unrealized (losses) gains on foreign currency translation:
Unrealized foreign currency translation (losses) gains arising during the period	0	0	0	0
Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation	0	0	0	0
Unrealized (losses) gains on foreign currency translation, net	0	0	0	0
Total other comprehensive (loss) income	0	0	0	(41)
Comprehensive income (loss)	98,698	70,598	198,053	153,416
Less: comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	98,698	70,598	198,053	153,416
Combined Non- Guarantor Subsidiaries
Condensed Statement of Comprehensive Income
Net income (loss)	114,409	81,711	307,946	175,647
Unrealized gains (losses) on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period		(4,024)		6,441
Reclassification adjustment for losses included in net income		2,348		2,478
Unrealized (losses) gains on public investments, net		(1,676)		8,919
Unrealized (losses) gains on interest rate hedge agreements:
Unrealized interest rate hedge gains (losses) arising during the period	0	(139)	0	(221)
Reclassification adjustment for amortization of interest (income) expense included in net income	0	2	0	3
Unrealized (losses) gains on interest rate hedge agreements, net	0	(137)	0	(218)
Unrealized (losses) gains on foreign currency translation:
Unrealized foreign currency translation (losses) gains arising during the period	(3,243)	2,744	(3,572)	3,756
Reclassification adjustment for cumulative foreign currency translation losses included in net income upon sale or liquidation	0	0	0	2,421
Unrealized (losses) gains on foreign currency translation, net	(3,243)	2,744	(3,572)	6,177
Total other comprehensive (loss) income	(3,243)	931	(3,572)	14,878
Comprehensive income (loss)	111,166	82,642	304,374	190,525
Less: comprehensive income attributable to noncontrolling interests	(5,817)	(7,283)	(11,705)	(13,131)
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	$ 105,349	$ 75,359	$ 292,669	$ 177,394

Condensed consolidating finan70

Condensed consolidating financial information Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net income	$ 60,547	$ 41,496	$ 202,065	$ 89,051
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	118,852	104,098	233,071	201,281
Loss on early extinguishment of debt	0	0	0	670
Gain (loss) on sale of real estate - rental properties	0	0	0	(270)
Impairment of real estate	6,311	203	6,311	203
Gain (loss) on sale of real estate - land parcels			0	(111)
Equity in earnings of unconsolidated real estate JVs	(1,090)	(589)	(2,234)	(950)
Distributions of earnings from unconsolidated real estate joint ventures			287	249
Amortization of loan fees			5,136	5,738
Amortization of debt discounts (premiums)			(1,181)	(1,221)
Amortization of acquired below-market leases			(11,368)	(10,363)
Deferred rent			(55,890)	(53,497)
Stock compensation expense			15,223	10,756
Equity in earnings of affiliates	0	0	0	0
Investment income			(98,091)	(962)
Changes in operating assets and liabilities:
Tenant receivables			1,552	1,354
Deferred leasing costs			(29,705)	(26,811)
Other assets			(15,055)	(4,654)
Accounts payable, accrued expenses, and tenant security deposits			8,120	13,283
Net cash provided by operating activities			258,241	223,746
Investing Activities
Proceeds from sale of properties			0	3,528
Additions to real estate			(431,225)	(436,377)
Purchases of real estate			(688,698)	(480,543)
Deposits for investing activities			5,500	450
Investments in subsidiaries			0	0
Acquisition of interest in unconsolidated joint venture			(35,922)	0
Investments in unconsolidated real estate joint ventures			(44,486)	(163)
Additions to investments			(118,775)	(81,192)
Sales of investments			44,707	12,577
Net cash used in investing activities			(1,268,899)	(981,720)
Financing Activities
Borrowings from secured notes payable			9,044	117,666
Repayments of borrowings from secured notes payable			(3,162)	(1,677)
Proceeds from issuance of unsecured senior notes payable			899,321	424,384
Borrowings from unsecured senior line of credit			2,469,000	2,069,000
Repayments of borrowings from unsecured senior line of credit			(2,519,000)	(1,797,000)
Repayments of borrowings from unsecured senior bank term loans			0	(200,000)
Transfers to/from parent company			0	0
Payment of loan fees			(8,003)	(4,344)
Repurchase of Series D preferred stock			0	(17,934)
Redemption of Series E preferred stock			0	(130,350)
Proceeds from the issuance of common stock			400,207	459,607
Dividends on common stock			(183,040)	(149,296)
Dividends on preferred stock			(2,604)	(7,015)
Contributions from noncontrolling interests			14,564	8,505
Distributions to and purchases of noncontrolling interests			(19,841)	(10,791)
Net cash provided by financing activities			1,056,486	760,755
Effect of foreign exchange rate changes on cash and cash equivalents			(1,173)	732
Net increase (decrease) in cash, cash equivalents, and restricted cash			44,655	3,513
Cash, cash equivalents, and restricted cash, beginning of period			277,186	141,366
Cash, cash equivalents, and restricted cash, end of period	321,841	144,879	321,841	144,879
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized			68,885	53,810
Non-Cash Investing Activities
Change in accrued construction			48,074	(25,138)
Contribution of real estate to an unconsolidated real estate joint venture			0	6,998
Eliminations
Operating Activities
Net income	(207,290)	(145,034)	(494,294)	(315,985)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	0	0	0	0
Loss on early extinguishment of debt			0	0
Gain (loss) on sale of real estate - rental properties				0
Impairment of real estate	0	0	0	0
Gain (loss) on sale of real estate - land parcels				0
Equity in earnings of unconsolidated real estate JVs	0	0	0	0
Distributions of earnings from unconsolidated real estate joint ventures			0	0
Amortization of loan fees			0	0
Amortization of debt discounts (premiums)			0	0
Amortization of acquired below-market leases			0	0
Deferred rent			0	0
Stock compensation expense			0	0
Equity in earnings of affiliates	207,290	145,034	494,294	315,985
Investment income			0	0
Changes in operating assets and liabilities:
Tenant receivables			0	0
Deferred leasing costs			0	0
Other assets			0	0
Accounts payable, accrued expenses, and tenant security deposits			0	0
Net cash provided by operating activities			0	0
Investing Activities
Proceeds from sale of properties				0
Additions to real estate			0	0
Purchases of real estate			0	0
Deposits for investing activities			0	0
Investments in subsidiaries			1,865,964	1,046,923
Acquisition of interest in unconsolidated joint venture			0
Investments in unconsolidated real estate joint ventures			0	0
Additions to investments			0	0
Sales of investments			0	0
Net cash used in investing activities			1,865,964	1,046,923
Financing Activities
Borrowings from secured notes payable			0	0
Repayments of borrowings from secured notes payable			0	0
Proceeds from issuance of unsecured senior notes payable			0	0
Borrowings from unsecured senior line of credit			0	0
Repayments of borrowings from unsecured senior line of credit			0	0
Repayments of borrowings from unsecured senior bank term loans				0
Transfers to/from parent company			(1,865,964)	(1,046,923)
Payment of loan fees			0	0
Repurchase of Series D preferred stock				0
Redemption of Series E preferred stock				0
Proceeds from the issuance of common stock			0	0
Dividends on common stock			0	0
Dividends on preferred stock			0	0
Contributions from noncontrolling interests			0	0
Distributions to and purchases of noncontrolling interests			0	0
Net cash provided by financing activities			(1,865,964)	(1,046,923)
Effect of foreign exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash, cash equivalents, and restricted cash			0	0
Cash, cash equivalents, and restricted cash, beginning of period			0	0
Cash, cash equivalents, and restricted cash, end of period	0	0	0	0
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized			0	0
Non-Cash Investing Activities
Change in accrued construction			0	0
Contribution of real estate to an unconsolidated real estate joint venture				0
Alexandria Real Estate Equities, Inc. (Issuer)
Operating Activities
Net income	54,730	34,221	190,360	75,932
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,647	1,721	3,324	3,430
Loss on early extinguishment of debt			0	670
Gain (loss) on sale of real estate - rental properties				0
Impairment of real estate	0	0	0	0
Gain (loss) on sale of real estate - land parcels				0
Equity in earnings of unconsolidated real estate JVs	0	0	0	0
Distributions of earnings from unconsolidated real estate joint ventures			0	0
Amortization of loan fees			4,260	3,774
Amortization of debt discounts (premiums)			378	290
Amortization of acquired below-market leases			0	0
Deferred rent			0	0
Stock compensation expense			15,223	10,756
Equity in earnings of affiliates	(106,552)	(73,077)	(292,720)	(159,548)
Investment income			43	0
Changes in operating assets and liabilities:
Tenant receivables			0	0
Deferred leasing costs			0	0
Other assets			(10,894)	(8,947)
Accounts payable, accrued expenses, and tenant security deposits			(726)	(7,109)
Net cash provided by operating activities			(90,752)	(80,752)
Investing Activities
Proceeds from sale of properties				0
Additions to real estate			0	0
Purchases of real estate			0	0
Deposits for investing activities			0	0
Investments in subsidiaries			(1,010,580)	(573,334)
Acquisition of interest in unconsolidated joint venture			0
Investments in unconsolidated real estate joint ventures			0	0
Additions to investments			0	0
Sales of investments			0	0
Net cash used in investing activities			(1,010,580)	(573,334)
Financing Activities
Borrowings from secured notes payable			0	0
Repayments of borrowings from secured notes payable			0	0
Proceeds from issuance of unsecured senior notes payable			899,321	424,384
Borrowings from unsecured senior line of credit			2,469,000	2,069,000
Repayments of borrowings from unsecured senior line of credit			(2,519,000)	(1,797,000)
Repayments of borrowings from unsecured senior bank term loans				(200,000)
Transfers to/from parent company			96,432	21,995
Payment of loan fees			(8,003)	(3,957)
Repurchase of Series D preferred stock				(17,934)
Redemption of Series E preferred stock				(130,350)
Proceeds from the issuance of common stock			400,207	459,607
Dividends on common stock			(183,040)	(149,296)
Dividends on preferred stock			(2,604)	(7,015)
Contributions from noncontrolling interests			0	0
Distributions to and purchases of noncontrolling interests			0	0
Net cash provided by financing activities			1,152,313	669,434
Effect of foreign exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash, cash equivalents, and restricted cash			50,981	15,348
Cash, cash equivalents, and restricted cash, beginning of period			130,516	30,705
Cash, cash equivalents, and restricted cash, end of period	181,497	46,053	181,497	46,053
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized			56,392	41,598
Non-Cash Investing Activities
Change in accrued construction			0	0
Contribution of real estate to an unconsolidated real estate joint venture				0
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Operating Activities
Net income	98,698	70,598	198,053	153,457
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	0	0	0	0
Loss on early extinguishment of debt			0	0
Gain (loss) on sale of real estate - rental properties				0
Impairment of real estate	0	0	0	0
Gain (loss) on sale of real estate - land parcels				0
Equity in earnings of unconsolidated real estate JVs	0	0	0	0
Distributions of earnings from unconsolidated real estate joint ventures			0	0
Amortization of loan fees			0	0
Amortization of debt discounts (premiums)			0	0
Amortization of acquired below-market leases			0	0
Deferred rent			0	0
Stock compensation expense			0	0
Equity in earnings of affiliates	(98,795)	(70,597)	(197,677)	(153,445)
Investment income			(375)	(5)
Changes in operating assets and liabilities:
Tenant receivables			0	0
Deferred leasing costs			0	0
Other assets			0	0
Accounts payable, accrued expenses, and tenant security deposits			(2)	(12)
Net cash provided by operating activities			(1)	(5)
Investing Activities
Proceeds from sale of properties				0
Additions to real estate			0	0
Purchases of real estate			0	0
Deposits for investing activities			0	0
Investments in subsidiaries			(838,102)	(464,024)
Acquisition of interest in unconsolidated joint venture			0
Investments in unconsolidated real estate joint ventures			0	0
Additions to investments			0	0
Sales of investments			377	204
Net cash used in investing activities			(837,725)	(463,820)
Financing Activities
Borrowings from secured notes payable			0	0
Repayments of borrowings from secured notes payable			0	0
Proceeds from issuance of unsecured senior notes payable			0	0
Borrowings from unsecured senior line of credit			0	0
Repayments of borrowings from unsecured senior line of credit			0	0
Repayments of borrowings from unsecured senior bank term loans				0
Transfers to/from parent company			837,717	463,825
Payment of loan fees			0	0
Repurchase of Series D preferred stock				0
Redemption of Series E preferred stock				0
Proceeds from the issuance of common stock			0	0
Dividends on common stock			0	0
Dividends on preferred stock			0	0
Contributions from noncontrolling interests			0	0
Distributions to and purchases of noncontrolling interests			0	0
Net cash provided by financing activities			837,717	463,825
Effect of foreign exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash, cash equivalents, and restricted cash			(9)	0
Cash, cash equivalents, and restricted cash, beginning of period			9	0
Cash, cash equivalents, and restricted cash, end of period	0	0	0	0
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized			0	0
Non-Cash Investing Activities
Change in accrued construction			0	0
Contribution of real estate to an unconsolidated real estate joint venture				0
Combined Non- Guarantor Subsidiaries
Operating Activities
Net income	114,409	81,711	307,946	175,647
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	117,205	102,377	229,747	197,851
Loss on early extinguishment of debt			0	0
Gain (loss) on sale of real estate - rental properties				(270)
Impairment of real estate	6,311	203	6,311	203
Gain (loss) on sale of real estate - land parcels				(111)
Equity in earnings of unconsolidated real estate JVs	(1,090)	(589)	(2,234)	(950)
Distributions of earnings from unconsolidated real estate joint ventures			287	249
Amortization of loan fees			876	1,964
Amortization of debt discounts (premiums)			(1,559)	(1,511)
Amortization of acquired below-market leases			(11,368)	(10,363)
Deferred rent			(55,890)	(53,497)
Stock compensation expense			0	0
Equity in earnings of affiliates	(1,943)	(1,360)	(3,897)	(2,992)
Investment income			(97,759)	(957)
Changes in operating assets and liabilities:
Tenant receivables			1,552	1,354
Deferred leasing costs			(29,705)	(26,811)
Other assets			(4,161)	4,293
Accounts payable, accrued expenses, and tenant security deposits			8,848	20,404
Net cash provided by operating activities			348,994	304,503
Investing Activities
Proceeds from sale of properties				3,528
Additions to real estate			(431,225)	(436,377)
Purchases of real estate			(688,698)	(480,543)
Deposits for investing activities			5,500	450
Investments in subsidiaries			(17,282)	(9,565)
Acquisition of interest in unconsolidated joint venture			(35,922)
Investments in unconsolidated real estate joint ventures			(44,486)	(163)
Additions to investments			(118,775)	(81,192)
Sales of investments			44,330	12,373
Net cash used in investing activities			(1,286,558)	(991,489)
Financing Activities
Borrowings from secured notes payable			9,044	117,666
Repayments of borrowings from secured notes payable			(3,162)	(1,677)
Proceeds from issuance of unsecured senior notes payable			0	0
Borrowings from unsecured senior line of credit			0	0
Repayments of borrowings from unsecured senior line of credit			0	0
Repayments of borrowings from unsecured senior bank term loans				0
Transfers to/from parent company			931,815	561,103
Payment of loan fees			0	(387)
Repurchase of Series D preferred stock				0
Redemption of Series E preferred stock				0
Proceeds from the issuance of common stock			0	0
Dividends on common stock			0	0
Dividends on preferred stock			0	0
Contributions from noncontrolling interests			14,564	8,505
Distributions to and purchases of noncontrolling interests			(19,841)	(10,791)
Net cash provided by financing activities			932,420	674,419
Effect of foreign exchange rate changes on cash and cash equivalents			(1,173)	732
Net increase (decrease) in cash, cash equivalents, and restricted cash			(6,317)	(11,835)
Cash, cash equivalents, and restricted cash, beginning of period			146,661	110,661
Cash, cash equivalents, and restricted cash, end of period	$ 140,344	$ 98,826	140,344	98,826
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized			12,493	12,212
Non-Cash Investing Activities
Change in accrued construction			$ 48,074	(25,138)
Contribution of real estate to an unconsolidated real estate joint venture				$ 6,998