Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 28, 2022
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Registrant Name	Starwood Real Estate Income Trust, Inc.
Entity Central Index Key	0001711929
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Public Float	$ 0
Entity File Number	000-56046
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	82-2023409
Entity Address, Address Line One	2340 Collins Avenue
Entity Address, City or Town	Miami Beach
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33139
City Area Code	305
Local Phone Number	695-5500
Document Annual Report	true
Document Transition Report	false
Auditor Name	Deloitte & Touche LLP
Auditor Firm ID	34
Auditor Location	New York, New York
Common Stock Class T
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		5,358,693
Title of 12(g) Security	Class T Common Stock, $0.01 par value per share
No Trading Symbol Flag	true
Common Stock Class S
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		188,684,205
Title of 12(g) Security	Class S Common Stock, $0.01 par value per share
No Trading Symbol Flag	true
Common Stock Class D
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		27,451,364
Title of 12(g) Security	Class D Common Stock, $0.01 par value per share
No Trading Symbol Flag	true
Common Stock Class I
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		201,947,123
Title of 12(g) Security	Class I Common Stock, $0.01 par value per share
No Trading Symbol Flag	true