Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 02, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-32319
Entity Registrant Name	Sunstone Hotel Investors, Inc.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	20-1296886
Entity Address, Address Line One	200 Spectrum Center Drive, 21st Floor
Entity Address, City or Town	Irvine
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92618
City Area Code	949
Local Phone Number	330-4000
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		219,042,657
Entity Central Index Key	0001295810
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	SHO
Security Exchange Name	NYSE
Series F Cumulative Redeemable Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Series F Cumulative Redeemable Preferred Stock, $0.01 par value
Trading Symbol	SHO.PRF
Security Exchange Name	NYSE
Series H Cumulative Redeemable Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Series H Cumulative Redeemable Preferred Stock, $0.01 par value
Trading Symbol	SHO.PRH
Security Exchange Name	NYSE
Series I Cumulative Redeemable Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Series I Cumulative Redeemable Preferred Stock, $0.01 par value
Trading Symbol	SHO.PRI
Security Exchange Name	NYSE