Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Dividend paid	Dividend declared	Series C Cumulative Preferred Stock	Series C Cumulative Preferred Stock Dividend paid	Series C Cumulative Preferred Stock Dividend declared	Series D Cumulative Redeemable Preferred Stock	Series D Cumulative Redeemable Preferred Stock Dividend paid	Series D Cumulative Redeemable Preferred Stock Dividend declared	Series E Cumulative Redeemable Preferred Stock	Series E Cumulative Redeemable Preferred Stock Dividend paid	Preferred Stock	Preferred Stock Series C Cumulative Preferred Stock	Preferred Stock Series D Cumulative Redeemable Preferred Stock	Preferred Stock Series E Cumulative Redeemable Preferred Stock	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Series C Cumulative Preferred Stock	Additional Paid-in Capital Series D Cumulative Redeemable Preferred Stock	Additional Paid-in Capital Series E Cumulative Redeemable Preferred Stock	Distributions in Excess of Accumulated Earnings	Distributions in Excess of Accumulated Earnings Dividend paid	Distributions in Excess of Accumulated Earnings Dividend declared	Distributions in Excess of Accumulated Earnings Series C Cumulative Preferred Stock	Distributions in Excess of Accumulated Earnings Series C Cumulative Preferred Stock Dividend paid	Distributions in Excess of Accumulated Earnings Series C Cumulative Preferred Stock Dividend declared	Distributions in Excess of Accumulated Earnings Series D Cumulative Redeemable Preferred Stock Dividend paid	Distributions in Excess of Accumulated Earnings Series D Cumulative Redeemable Preferred Stock Dividend declared	Distributions in Excess of Accumulated Earnings Series E Cumulative Redeemable Preferred Stock Dividend paid	Accumulated Other Comprehensive (Loss)	Total Saul Centers, Inc.	Total Saul Centers, Inc. Dividend paid	Total Saul Centers, Inc. Dividend declared	Total Saul Centers, Inc. Series C Cumulative Preferred Stock	Total Saul Centers, Inc. Series C Cumulative Preferred Stock Dividend paid	Total Saul Centers, Inc. Series C Cumulative Preferred Stock Dividend declared	Total Saul Centers, Inc. Series D Cumulative Redeemable Preferred Stock	Total Saul Centers, Inc. Series D Cumulative Redeemable Preferred Stock Dividend paid	Total Saul Centers, Inc. Series D Cumulative Redeemable Preferred Stock Dividend declared	Total Saul Centers, Inc. Series E Cumulative Redeemable Preferred Stock	Noncontrolling Interests	Noncontrolling Interests Dividend paid	Noncontrolling Interests Dividend declared
Beginning balance at Dec. 31, 2016	$ 373,249											$ 180,000				$ 217	$ 328,171				$ (188,584)									$ (1,299)	$ 318,505										$ 54,744
Issuance of common stock:
Shares issued pursuant to dividend reinvestment plan	15,750															2	15,748														15,750
Shares issued due to exercise of employee stock options and issuance of directors' deferred stock	8,673															2	8,671														8,673
Issuance of partnership units	6,735																																								6,735
Net income	60,668																				48,257										48,257										12,411
Change in unrealized loss on cash flow hedge	812																													603	603										209
Preferred stock distributions:
Preferred stock distributions					$ (9,282)	$ (3,093)																			$ (9,282)	$ (3,093)									$ (9,282)	$ (3,093)
Common stock distributions		$ (44,969)																				$ (33,490)										$ (33,490)										$ (11,479)
Distributions payable common stock and distributions payable partnership units			$ (15,440)																				$ (11,518)										$ (11,518)										$ (3,922)
Ending balance at Dec. 31, 2017	393,103											180,000				221	352,590				(197,710)									(696)	334,405										58,698
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of cumulative preferred stock							$ 72,367							$ 75,000					$ (2,633)																		$ 72,367
Redemption of Series of Series C Cumulative preferred stock				$ (75,017)									$ (75,000)					$ 2,311						$ (2,328)										$ (75,017)
Issuance of common stock:
Shares issued pursuant to dividend reinvestment plan	28,823															6	28,817														28,823
Shares issued due to exercise of employee stock options and issuance of directors' deferred stock	3,448																3,448														3,448
Issuance of partnership units	14,159																																								14,159
Net income	63,059																				50,554										50,554										12,505
Change in unrealized loss on cash flow hedge	594																													441	441										153
Preferred stock distributions:
Preferred stock distributions					(6,145)	$ (1,805)		$ (3,164)	$ (1,148)																(6,145)	$ (1,805)	$ (3,164)	$ (1,148)							(6,145)	$ (1,805)		$ (3,164)	$ (1,148)
Common stock distributions		(46,900)																				(34,841)										(34,841)										(12,059)
Distributions payable common stock and distributions payable partnership units			(16,154)																				(12,006)										(12,006)										(4,148)
Ending balance at Dec. 31, 2018	425,220											180,000				227	384,533				(208,593)									(255)	355,912										69,308
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of cumulative preferred stock										$ 106,265					$ 110,000					$ (3,735)																				$ 106,265
Redemption of Series of Series C Cumulative preferred stock				$ 105,000									$ 105,000					$ (3,235)						$ (3,235)										$ 105,000
Issuance of common stock:
Shares issued pursuant to dividend reinvestment plan	22,498															4	22,494														22,498
Shares issued due to exercise of employee stock options and issuance of directors' deferred stock	4,400															1	4,399														4,400
Issuance of partnership units	3,180																																								3,180
Net income	64,196																				51,723										51,723										12,473
Change in unrealized loss on cash flow hedge	343																													255	255										88
Preferred stock distributions:
Preferred stock distributions			(1,650)		$ (5,736)			$ (3,444)	$ (1,148)		$ (257)												(1,650)		$ (5,736)		$ (3,444)	$ (1,148)	$ (257)				(1,650)		$ (5,736)			$ (3,444)	$ (1,148)
Common stock distributions		$ (49,056)																				$ (36,562)										$ (36,562)										$ (12,494)
Distributions payable common stock and distributions payable partnership units			$ (16,455)																				$ (12,275)										$ (12,275)										$ (4,180)
Ending balance at Dec. 31, 2019	$ 443,356											$ 185,000				$ 232	$ 410,926				$ (221,177)									$ 0	$ 374,981										$ 68,375