Consolidated Statement of Equity (Unaudited) - USD ($) $ in Thousands	Total	Series C Cumulative Preferred Stock	Series D Cumulative Redeemable Preferred Stock	Series E Cumulative Redeemable Preferred Stock	Total Saul Centers, Inc.	Total Saul Centers, Inc. Series C Cumulative Preferred Stock	Total Saul Centers, Inc. Series D Cumulative Redeemable Preferred Stock	Total Saul Centers, Inc. Series E Cumulative Redeemable Preferred Stock	Preferred Stock	Common Stock	Additional Paid-in Capital	Distributions in Excess of Accumulated Earnings	Distributions in Excess of Accumulated Earnings Series C Cumulative Preferred Stock	Distributions in Excess of Accumulated Earnings Series D Cumulative Redeemable Preferred Stock	Distributions in Excess of Accumulated Earnings Series E Cumulative Redeemable Preferred Stock	Accumulated Other Comprehensive (Loss)	Noncontrolling Interests
Beginning Balance at Dec. 31, 2018	$ 425,220				$ 355,912				$ 180,000	$ 227	$ 384,533	$ (208,593)				$ (255)	$ 69,308
Issuance of shares of common stock:
Issuance of shares pursuant to dividend reinvestment plan	6,171				6,171					1	6,170
Issuance of shares due to exercise of employee stock options and issuance of directors’ deferred shares	420				420					1	419
Issuance of partnership units pursuant to dividend reinvestment plan	705																705
Net income	17,077				13,447							13,447					3,630
Change in unrealized loss on cash flow hedge	(46)				(34)											(34)	(12)
Distributions payable preferred stock:
Preferred stock distributions		$ (1,805)	$ (1,148)			$ (1,805)	$ (1,148)						$ (1,805)	$ (1,148)
Distributions payable, common stock and partnership units	(16,263)				(12,108)							(12,108)					(4,155)
Ending Balance at Mar. 31, 2019	430,331				360,855				180,000	229	391,122	(210,207)				(289)	69,476
Beginning Balance at Dec. 31, 2018	425,220				355,912				180,000	227	384,533	(208,593)				(255)	69,308
Issuance of shares of common stock:
Net income	33,827
Change in unrealized loss on cash flow hedge	(173)
Ending Balance at Jun. 30, 2019	436,609				366,784				180,000	230	399,047	(212,109)				(384)	69,825
Beginning Balance at Mar. 31, 2019	430,331				360,855				180,000	229	391,122	(210,207)				(289)	69,476
Issuance of shares of common stock:
Issuance of shares pursuant to dividend reinvestment plan	5,128				5,128					1	5,127
Issuance of shares due to exercise of employee stock options and issuance of directors’ deferred shares	2,798				2,798					0	2,798
Issuance of partnership units pursuant to dividend reinvestment plan	1,029																1,029
Net income	16,750				13,232							13,232					3,518
Change in unrealized loss on cash flow hedge	(127)				(95)											(95)	(32)
Distributions payable preferred stock:
Preferred stock distributions		$ (1,805)	(1,148)			$ (1,805)	(1,148)						$ (1,805)	(1,148)
Distributions payable, common stock and partnership units	(16,347)				(12,181)							(12,181)					(4,166)
Ending Balance at Jun. 30, 2019	436,609				366,784				180,000	230	399,047	(212,109)				(384)	69,825
Beginning Balance at Dec. 31, 2019	443,356				374,981				185,000	232	410,926	(221,177)				0	68,375
Issuance of shares of common stock:
Issuance of shares pursuant to dividend reinvestment plan	4,081				4,081					1	4,080
Issuance of shares due to exercise of employee stock options and issuance of directors’ deferred shares	956				956					0	956
Issuance of partnership units pursuant to dividend reinvestment plan	734																734
Net income	16,829				13,264							13,264					3,565
Distributions payable preferred stock:
Preferred stock distributions			(1,148)	$ (1,650)			(1,148)	$ (1,650)						(1,148)	$ (1,650)
Distributions payable, common stock and partnership units	(16,552)				(12,364)							(12,364)					(4,188)
Ending Balance at Mar. 31, 2020	446,606				378,120				185,000	233	415,962	(223,075)				0	68,486
Beginning Balance at Dec. 31, 2019	443,356				374,981				185,000	232	410,926	(221,177)				0	68,375
Issuance of shares of common stock:
Net income	27,037
Change in unrealized loss on cash flow hedge	0
Ending Balance at Jun. 30, 2020	438,286				372,108				185,000	233	416,793	(229,918)				0	66,178
Beginning Balance at Mar. 31, 2020	446,606				378,120				185,000	233	415,962	(223,075)				0	68,486
Issuance of shares of common stock:
Issuance of shares pursuant to dividend reinvestment plan	407				407					0	407
Issuance of shares due to exercise of employee stock options and issuance of directors’ deferred shares	424				424					0	424
Net income	10,208				8,328							8,328					1,880
Change in unrealized loss on cash flow hedge	0
Distributions payable preferred stock:
Preferred stock distributions			$ (1,148)	$ (1,650)			$ (1,148)	$ (1,650)						$ (1,148)	$ (1,650)
Distributions payable, common stock and partnership units	(16,561)				(12,373)							(12,373)					(4,188)
Ending Balance at Jun. 30, 2020	$ 438,286				$ 372,108				$ 185,000	$ 233	$ 416,793	$ (229,918)				$ 0	$ 66,178