Cover Page - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 18, 2021	Jun. 30, 2020
Document Information [Line Items]
Document type	10-K
Document Annual Report	true
Document period end date	Dec. 31, 2020
Current fiscal year end date	--12-31
Document Transition Report	false
Entity File Number	1-12254
Entity registrant name	SAUL CENTERS, INC.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	52-1833074
Entity Address, Address Line One	7501 Wisconsin Avenue
Entity Address, Address Line Two	Suite 1500E
Entity Address, City or Town	Bethesda
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20814-6522
City Area Code	301
Local Phone Number	986-6200
Entity well-known seasoned issuer	Yes
Entity voluntary filers	No
Entity current reporting status	Yes
Entity Interactive Data Current	Yes
Entity filer category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity common stock, shares outstanding		23.5
Entity public float			$ 419.8
Documents Incorporated by Reference	Registrant incorporates by reference into Part III (Items 10, 11, 12, 13 and 14) of this Annual Report on Form 10-K portions of registrant’s definitive Proxy Statement for the 2021 Annual Meeting of Stockholders to be filed with the Securities Exchange Commission pursuant to Regulation 14A. The definitive Proxy Statement will be filed with the Commission not later than 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.
Amendment flag	false
Document fiscal year focus	2020
Document fiscal period focus	FY
Entity central index key	0000907254
Common Stock, Par Value $0.01 Per Share
Document Information [Line Items]
Title of 12(b) Security	Common Stock, Par Value $0.01 Per Share
Security Exchange Name	NYSE
Trading symbol	BFS
Depositary Shares each representing 1/100th of a share of 6.125% Series D Cumulative Redeemable Preferred Stock, Par Value $0.01 Per Share
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares each representing 1/100th of a share of 6.125% Series D Cumulative Redeemable Preferred Stock, Par Value $0.01 Per Share
Security Exchange Name	NYSE
Trading symbol	BFS/PRD
Depositary Shares each representing 1/100th of a share of 6.000% Series E Cumulative Redeemable Preferred Stock, Par Value $0.01 Per Share
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares each representing 1/100th of a share of 6.000% Series E Cumulative Redeemable Preferred Stock, Par Value $0.01 Per Share
Security Exchange Name	NYSE
Trading symbol	BFS/PRE