Condensed consolidating financial information Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	12 Months Ended
	May 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Activities
Net income		$ 140,249	$ 105,528	$ 135,393
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization		190,778	192,005	158,026
Loss on early extinguishment of debt		1,992	2,225	6,485
Gain on sale of land parcels		(4,824)	(1,864)	(46)
Loss (gain) on sale of real estate		121	(1,564)	0
Impairment of real estate		0	11,400	994
Impairment of land parcel		0	2,050	0
Amortization of loan fees and costs		9,936	9,832	9,300
Amortization of debt premiums/discounts		529	511	3,819
Amortization of acquired above and below market leases		(3,316)	(3,200)	(9,332)
Deferred rent		(27,935)	(28,456)	(26,797)
Stock compensation expense		15,552	14,160	11,755
Equity in (income) loss related to subsidiaries		0	0	0
Investment gains		(7,050)	(15,018)	(4,846)
Investment losses		1,480	2,637	1,795
Changes in operating assets and liabilities:
Restricted cash		899	(261)	(465)
Tenant receivables		(1,519)	(981)	(2,359)
Deferred leasing costs		(54,825)	(45,099)	(56,226)
Other assets		(6,298)	(4,069)	(22,359)
Intercompany receivables and payables		0	0	0
Accounts payable, accrued expenses, and tenant security deposits		56,958	65,697	41,823
Net cash provided by operating activities		312,727	305,533	246,960
Investing Activities
Proceeds from sale of properties		153,968	36,179	20,078
Additions to properties		(593,389)	(549,030)	(430,038)
Purchase of properties		(122,069)	(42,171)	(305,030)
Change in restricted cash related to construction projects		7,655	(9,377)	(2,183)
Distribution from unconsolidated real estate entity		0	22,250	0
Contributions to unconsolidated real estate entity		(17,987)	(6,700)	(5,256)
Investments in subsidiaries		0	0	0
Additions to investments		(36,078)	(36,294)	(27,999)
Proceeds from investments		16,525	27,043	16,849
Net cash used in investing activities		(591,375)	(558,100)	(733,579)
Financing Activities
Borrowings from secured notes payable		28,489	17,810	0
Repayments of borrowings from secured notes payable		(36,219)	(26,367)	(66,849)
Proceeds from issuance of unsecured senior notes payable		498,561	544,650	0
Principal borrowings from unsecured senior line of credit		729,000	847,147	1,406,000
Repayments of borrowings from unsecured senior line of credit		(1,091,000)	(651,147)	(1,784,000)
Principal borrowings from unsecured senior bank term loans		0	0	1,350,000
Repayment of unsecured senior bank term loan		(250,000)	(250,000)	(500,000)
Repurchase of unsecured senior convertible notes		(384)	(84,801)	(221,439)
Redemption of Series C Cumulative Redeemable Preferred Stock		0	(129,638)	0
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock		0	124,868	0
Transfers to/from parent company		0	0	0
Change in restricted cash related to financings		2,546	(7,428)	7,311
Deferred financing costs paid		(19,928)	(13,225)	(27,316)
Proceeds from common stock offering	534,469	534,469	97,890	451,539
Proceeds from exercise of stock options		0	155	2,117
Dividends paid on common stock		(169,076)	(126,498)	(106,889)
Dividends paid on preferred stock		(25,885)	(27,819)	(28,357)
Contributions by redeemable noncontrolling interests		0	0	9
Distributions to redeemable noncontrolling interests		(1,191)	(1,249)	(1,263)
Redemption of redeemable noncontrolling interests		0	(450)	0
Contributions by noncontrolling interests		0	1,875	1,000
Distributions to noncontrolling interests		(1,812)	(913)	(2,707)
Net cash provided by financing activities		197,570	314,860	479,156
Effect of foreign exchange rate changes on cash and cash equivalents		(2,197)	139	(5,230)
Net (decrease) increase in cash and cash equivalents		(83,275)	62,432	(12,693)
Cash and cash equivalents at beginning of period		140,971	78,539	91,232
Cash and cash equivalents at end of period		57,696	140,971	78,539
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized		59,857	52,561	52,324
Non-Cash Investing Activities
Note receivable from sale of real estate		38,820	6,125	0
Write-off of fully amortized improvements		0	(17,730)	0
Change in accrued capital expenditures		(21,310)	46,087	3,492
Alexandria Real Estate Equities, Inc. (Issuer)
Operating Activities
Net income		136,217	102,126	131,418
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization		5,907	6,490	4,938
Loss on early extinguishment of debt		1,992	2,225	6,485
Gain on sale of land parcels		0	0	0
Loss (gain) on sale of real estate		0	0
Impairment of real estate			6,400	0
Impairment of land parcel			0
Amortization of loan fees and costs		6,914	9,204	6,915
Amortization of debt premiums/discounts		111	114	3,534
Amortization of acquired above and below market leases		0	0	0
Deferred rent		(82)	(224)	100
Stock compensation expense		15,552	14,160	11,755
Equity in (income) loss related to subsidiaries		(220,158)	(194,566)	(202,829)
Investment gains		0	0	0
Investment losses		0	0	0
Changes in operating assets and liabilities:
Restricted cash		(2)	(12)	4
Tenant receivables		0	11	(12)
Deferred leasing costs		(37)	(305)	(699)
Other assets		(5,606)	1,329	2,550
Intercompany receivables and payables		3,021	(826)	(1,418)
Accounts payable, accrued expenses, and tenant security deposits		(13,485)	6,172	6,274
Net cash provided by operating activities		(69,656)	(47,702)	(30,985)
Investing Activities
Proceeds from sale of properties		10,796	0	0
Additions to properties		0	(1,313)	(1,624)
Purchase of properties		0	0	0
Change in restricted cash related to construction projects		0	0	0
Distribution from unconsolidated real estate entity			0
Contributions to unconsolidated real estate entity		0	0	0
Investments in subsidiaries		(236,218)	(197,665)	(548,884)
Additions to investments		0	0	0
Proceeds from investments		0	0	0
Net cash used in investing activities		(225,422)	(198,978)	(550,508)
Financing Activities
Borrowings from secured notes payable		0	0
Repayments of borrowings from secured notes payable		0	0	0
Proceeds from issuance of unsecured senior notes payable		498,561	544,650
Principal borrowings from unsecured senior line of credit		729,000	847,147	1,406,000
Repayments of borrowings from unsecured senior line of credit		(1,091,000)	(651,147)	(1,784,000)
Principal borrowings from unsecured senior bank term loans				1,350,000
Repayment of unsecured senior bank term loan		(250,000)	(250,000)	(500,000)
Repurchase of unsecured senior convertible notes		(384)	(84,801)	(221,439)
Redemption of Series C Cumulative Redeemable Preferred Stock			(129,638)
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock			124,868
Transfers to/from parent company		0	0	0
Change in restricted cash related to financings		(1)	0	0
Deferred financing costs paid		(14,383)	(10,180)	(25,493)
Proceeds from common stock offering		534,469	97,890	451,539
Proceeds from exercise of stock options			155	2,117
Dividends paid on common stock		(169,076)	(126,498)	(106,889)
Dividends paid on preferred stock		(25,885)	(27,819)	(28,357)
Contributions by redeemable noncontrolling interests				0
Distributions to redeemable noncontrolling interests		0	0	0
Redemption of redeemable noncontrolling interests			12
Contributions by noncontrolling interests			0	0
Distributions to noncontrolling interests		0	0	0
Net cash provided by financing activities		211,301	334,639	543,478
Effect of foreign exchange rate changes on cash and cash equivalents		0	0	0
Net (decrease) increase in cash and cash equivalents		(83,777)	87,959	(38,015)
Cash and cash equivalents at beginning of period		98,567	10,608	48,623
Cash and cash equivalents at end of period		14,790	98,567	10,608
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized		37,073	39,298	30,292
Non-Cash Investing Activities
Note receivable from sale of real estate		29,820	0
Write-off of fully amortized improvements			0
Change in accrued capital expenditures		0	(2,000)	(987)
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Operating Activities
Net income		205,919	184,428	191,674
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization		0	0	0
Loss on early extinguishment of debt		0	0	0
Gain on sale of land parcels		0	0	0
Loss (gain) on sale of real estate		0	0
Impairment of real estate		0		0
Impairment of land parcel		0	0
Amortization of loan fees and costs		0	0	0
Amortization of debt premiums/discounts		0	0	0
Amortization of acquired above and below market leases		0	0	0
Deferred rent		0	0	0
Stock compensation expense		0	0	0
Equity in (income) loss related to subsidiaries		(205,993)	(183,139)	(192,143)
Investment gains		(3)	(1,510)	(427)
Investment losses		78	221	883
Changes in operating assets and liabilities:
Restricted cash		0	0	0
Tenant receivables		0	0	0
Deferred leasing costs		0	0	0
Other assets		0	0	0
Intercompany receivables and payables		0	0	0
Accounts payable, accrued expenses, and tenant security deposits		0	0	0
Net cash provided by operating activities		1	0	(13)
Investing Activities
Proceeds from sale of properties		0	0	0
Additions to properties		0	0	0
Purchase of properties		0	0	0
Change in restricted cash related to construction projects		0	0	0
Distribution from unconsolidated real estate entity			0
Contributions to unconsolidated real estate entity		0	0	0
Investments in subsidiaries		(276,022)	(158,022)	(477,482)
Additions to investments		0	(353)	(2,451)
Proceeds from investments		1,018	2,600	3,471
Net cash used in investing activities		(275,004)	(155,775)	(476,462)
Financing Activities
Borrowings from secured notes payable		0	0
Repayments of borrowings from secured notes payable		0	0	0
Proceeds from issuance of unsecured senior notes payable		0	0
Principal borrowings from unsecured senior line of credit		0	0	0
Repayments of borrowings from unsecured senior line of credit		0	0	0
Principal borrowings from unsecured senior bank term loans				0
Repayment of unsecured senior bank term loan		0	0	0
Repurchase of unsecured senior convertible notes		0	0	0
Redemption of Series C Cumulative Redeemable Preferred Stock			0
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock			0
Transfers to/from parent company		273,089	157,689	475,873
Change in restricted cash related to financings		0	0	0
Deferred financing costs paid		0	0	0
Proceeds from common stock offering		0	0	0
Proceeds from exercise of stock options			0	0
Dividends paid on common stock		0	0	0
Dividends paid on preferred stock		0	0	0
Contributions by redeemable noncontrolling interests				0
Distributions to redeemable noncontrolling interests		0	0	0
Redemption of redeemable noncontrolling interests			0
Contributions by noncontrolling interests			0	0
Distributions to noncontrolling interests		0	0	0
Net cash provided by financing activities		273,089	157,689	475,873
Effect of foreign exchange rate changes on cash and cash equivalents		0	0	0
Net (decrease) increase in cash and cash equivalents		(1,914)	1,914	(602)
Cash and cash equivalents at beginning of period		1,914	0	602
Cash and cash equivalents at end of period		0	1,914	0
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized		0	0	0
Non-Cash Investing Activities
Note receivable from sale of real estate		0	0
Write-off of fully amortized improvements			0
Change in accrued capital expenditures		0	0	0
Combined Non- Guarantor Subsidiaries
Operating Activities
Net income		228,331	200,317	211,066
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization		184,871	185,515	153,088
Loss on early extinguishment of debt		0	0	0
Gain on sale of land parcels		(4,824)	(1,864)	(46)
Loss (gain) on sale of real estate		121	(1,564)
Impairment of real estate			5,000	994
Impairment of land parcel			2,050
Amortization of loan fees and costs		3,022	628	2,385
Amortization of debt premiums/discounts		418	397	285
Amortization of acquired above and below market leases		(3,316)	(3,200)	(9,332)
Deferred rent		(27,853)	(28,232)	(26,897)
Stock compensation expense		0	0	0
Equity in (income) loss related to subsidiaries		(4,067)	(3,638)	(3,793)
Investment gains		(7,047)	(13,508)	(4,419)
Investment losses		1,402	2,416	912
Changes in operating assets and liabilities:
Restricted cash		901	(249)	(469)
Tenant receivables		(1,519)	(992)	(2,347)
Deferred leasing costs		(54,788)	(44,794)	(55,527)
Other assets		(692)	(5,398)	(24,909)
Intercompany receivables and payables		(3,021)	826	1,418
Accounts payable, accrued expenses, and tenant security deposits		70,443	59,525	35,549
Net cash provided by operating activities		382,382	353,235	277,958
Investing Activities
Proceeds from sale of properties		143,172	36,179	20,078
Additions to properties		(593,389)	(547,717)	(428,414)
Purchase of properties		(122,069)	(42,171)	(305,030)
Change in restricted cash related to construction projects		7,655	(9,377)	(2,183)
Distribution from unconsolidated real estate entity			22,250
Contributions to unconsolidated real estate entity		(17,987)	(6,700)	(5,256)
Investments in subsidiaries		(13,445)	(1,179)	(11,951)
Additions to investments		(36,078)	(35,941)	(25,548)
Proceeds from investments		15,507	24,443	13,378
Net cash used in investing activities		(616,634)	(560,213)	(744,926)
Financing Activities
Borrowings from secured notes payable		28,489	17,810
Repayments of borrowings from secured notes payable		(36,219)	(26,367)	(66,849)
Proceeds from issuance of unsecured senior notes payable		0	0
Principal borrowings from unsecured senior line of credit		0	0	0
Repayments of borrowings from unsecured senior line of credit		0	0	0
Principal borrowings from unsecured senior bank term loans				0
Repayment of unsecured senior bank term loan		0	0	0
Repurchase of unsecured senior convertible notes		0	0	0
Redemption of Series C Cumulative Redeemable Preferred Stock			0
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock			0
Transfers to/from parent company		252,596	199,177	562,444
Change in restricted cash related to financings		2,547	(7,428)	7,311
Deferred financing costs paid		(5,545)	(3,045)	(1,823)
Proceeds from common stock offering		0	0	0
Proceeds from exercise of stock options			0	0
Dividends paid on common stock		0	0	0
Dividends paid on preferred stock		0	0	0
Contributions by redeemable noncontrolling interests				9
Distributions to redeemable noncontrolling interests		(1,191)	(1,249)	(1,263)
Redemption of redeemable noncontrolling interests			(462)
Contributions by noncontrolling interests			1,875	1,000
Distributions to noncontrolling interests		(1,812)	(913)	(2,707)
Net cash provided by financing activities		238,865	179,398	498,122
Effect of foreign exchange rate changes on cash and cash equivalents		(2,197)	139	(5,230)
Net (decrease) increase in cash and cash equivalents		2,416	(27,441)	25,924
Cash and cash equivalents at beginning of period		40,490	67,931	42,007
Cash and cash equivalents at end of period		42,906	40,490	67,931
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized		22,784	13,263	22,032
Non-Cash Investing Activities
Note receivable from sale of real estate		9,000	6,125
Write-off of fully amortized improvements			(17,730)
Change in accrued capital expenditures		(21,310)	48,087	4,479
Eliminations
Operating Activities
Net income		(430,218)	(381,343)	(398,765)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization		0	0	0
Loss on early extinguishment of debt		0	0	0
Gain on sale of land parcels		0	0	0
Loss (gain) on sale of real estate		0	0
Impairment of real estate			0	0
Impairment of land parcel			0
Amortization of loan fees and costs		0	0	0
Amortization of debt premiums/discounts		0	0	0
Amortization of acquired above and below market leases		0	0	0
Deferred rent		0	0	0
Stock compensation expense		0	0	0
Equity in (income) loss related to subsidiaries		430,218	381,343	398,765
Investment gains		0	0	0
Investment losses		0	0	0
Changes in operating assets and liabilities:
Restricted cash		0	0	0
Tenant receivables		0	0	0
Deferred leasing costs		0	0	0
Other assets		0	0	0
Intercompany receivables and payables		0	0	0
Accounts payable, accrued expenses, and tenant security deposits		0	0	0
Net cash provided by operating activities		0	0	0
Investing Activities
Proceeds from sale of properties		0	0	0
Additions to properties		0	0	0
Purchase of properties		0	0	0
Change in restricted cash related to construction projects		0	0	0
Distribution from unconsolidated real estate entity			0
Contributions to unconsolidated real estate entity		0	0	0
Investments in subsidiaries		525,685	356,866	1,038,317
Additions to investments		0	0	0
Proceeds from investments		0	0	0
Net cash used in investing activities		525,685	356,866	1,038,317
Financing Activities
Borrowings from secured notes payable		0	0
Repayments of borrowings from secured notes payable		0	0	0
Proceeds from issuance of unsecured senior notes payable		0	0
Principal borrowings from unsecured senior line of credit		0	0	0
Repayments of borrowings from unsecured senior line of credit		0	0	0
Principal borrowings from unsecured senior bank term loans				0
Repayment of unsecured senior bank term loan		0	0	0
Repurchase of unsecured senior convertible notes		0	0	0
Redemption of Series C Cumulative Redeemable Preferred Stock			0
Proceeds from issuance of Series E Cumulative Redeemable Preferred Stock			0
Transfers to/from parent company		(525,685)	(356,866)	(1,038,317)
Change in restricted cash related to financings		0	0	0
Deferred financing costs paid		0	0	0
Proceeds from common stock offering		0	0	0
Proceeds from exercise of stock options			0	0
Dividends paid on common stock		0	0	0
Dividends paid on preferred stock		0	0	0
Contributions by redeemable noncontrolling interests				0
Distributions to redeemable noncontrolling interests		0	0	0
Redemption of redeemable noncontrolling interests			0
Contributions by noncontrolling interests			0	0
Distributions to noncontrolling interests		0	0	0
Net cash provided by financing activities		(525,685)	(356,866)	(1,038,317)
Effect of foreign exchange rate changes on cash and cash equivalents		0	0	0
Net (decrease) increase in cash and cash equivalents		0	0	0
Cash and cash equivalents at beginning of period		0	0	0
Cash and cash equivalents at end of period		0	0	0
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest, net of interest capitalized		0	0	0
Non-Cash Investing Activities
Note receivable from sale of real estate		0	0
Write-off of fully amortized improvements			0
Change in accrued capital expenditures		$ 0	$ 0	$ 0