Noncontrolling Interests - Holders of Convertible Limited Partnership Units in the Operating Partnership (Details)		3 Months Ended		9 Months Ended
	Sep. 30, 2021 shares	Sep. 30, 2021 shares	Sep. 30, 2020 shares	Sep. 30, 2021 shares	Sep. 30, 2020 shares
Noncontrolling Interest [Line Items]
Limited partnership units (in shares)	8,100,000	8,100,000		8,100,000
Leasehold Interest Contributed In Contribution Agreement
Noncontrolling Interest [Line Items]
Number of partnership units issued in transaction (in shares)	469,740
Saul Holdings Limited Partnership
Noncontrolling Interest [Line Items]
Percentage of ownership interest of noncontrolling interest	25.10%	25.10%		25.10%
Third Party Investor
Noncontrolling Interest [Line Items]
Percentage of ownership interest of noncontrolling interest	1.50%	1.50%		1.50%
Noncontrolling Interests
Noncontrolling Interest [Line Items]
Limited partnership units, conversion ratio	1	1		1
Outstanding stock percent that should be acquired for rights to be exercised	39.90%	39.90%		39.90%
Limited partnership units convertible into shares of common stock, eligible for conversion	1,000,000	1,000,000		1,000,000
Fully converted partnership units and diluted weighted average shares outstanding		33,700,000	31,300,000	32,900,000	31,200,000
Partners capital account units placed In escrow				700,000
Noncontrolling Interests | Saul Holdings Limited Partnership
Noncontrolling Interest [Line Items]
Percentage of ownership interest of noncontrolling interest	26.60%	26.60%		26.60%
Limited partnership units, conversion ratio	1	1		1