Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 04, 2022
Document Type	10-Q
Document Period End Date	Jun. 30, 2022
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-37949
Entity Registrant Name	Innovative Industrial Properties, Inc.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	81-2963381
Entity Address, Address Line One	1389 Center Drive, Suite 200
Entity Address, City or Town	Park City
Entity Address, State or Province	UT
Entity Address, Postal Zip Code	84098
City Area Code	858
Local Phone Number	997-3332
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		27,973,429
Amendment Flag	false
Entity Central Index Key	0001677576
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Common Stock
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	IIPR
Security Exchange Name	NYSE
Series A Preferred Stock
Title of 12(b) Security	Series A Preferred Stock, par value $0.001 per share
Trading Symbol	IIPR-PA
Security Exchange Name	NYSE