Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Dividend paid	Dividend declared	Series C Preferred Stock Dividend paid	Series C Preferred Stock Dividend declared	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Deficit Dividend paid	Accumulated Deficit Dividend declared	Accumulated Deficit Series C Preferred Stock Dividend paid	Accumulated Deficit Series C Preferred Stock Dividend declared	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 Preferred Stock Dividend paid	Total Saul Centers, Inc. Series C Preferred Stock Dividend declared	Noncontrolling Interests	Noncontrolling Interests Dividend paid	Noncontrolling Interests Dividend declared
Beginning balance at Dec. 31, 2014	$ 339,257					$ 180,000	$ 209	$ 287,995	$ (173,774)					$ (1,894)	$ 292,536					$ 46,721
Issuance of common stock:
Shares issued pursuant to dividend reinvestment plan	10,650						3	10,647							10,650
Shares issued due to exercise of employee stock options and issuance of directors' deferred stock	6,367						1	6,366							6,367
Issuance of partnership units pursuant to dividend reinvestment plan	5,673																			5,673
Net income	52,931								42,468						42,468					10,463
Change in unrealized loss on cash flow hedge	124													92	92					32
Preferred stock distributions:
Preferred stock distributions				$ (9,282)	$ (3,093)							$ (9,282)	$ (3,093)					$ (9,282)	$ (3,093)
Common stock distributions		$ (36,614)								$ (27,265)						$ (27,265)					$ (9,349)
Distributions payable common stock and distributions payable partnership units			$ (12,286)								$ (9,145)						$ (9,145)					$ (3,141)
Ending balance at Dec. 31, 2015	353,727					180,000	213	305,008	(180,091)					(1,802)	303,328					50,399
Issuance of common stock:
Shares issued pursuant to dividend reinvestment plan	10,311						2	10,309							10,311
Shares issued due to exercise of employee stock options and issuance of directors' deferred stock	12,856						2	12,854							12,856
Issuance of partnership units pursuant to dividend reinvestment plan	6,910																			6,910
Net income	56,720								45,279						45,279					11,441
Change in unrealized loss on cash flow hedge	678													503	503					175
Preferred stock distributions:
Preferred stock distributions				(9,282)	(3,093)							(9,282)	(3,093)					(9,282)	(3,093)
Common stock distributions		(40,720)								(30,328)						(30,328)					(10,392)
Distributions payable common stock and distributions payable partnership units			(14,858)								(11,069)						(11,069)					(3,789)
Ending 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 pursuant to dividend reinvestment plan	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