Related Party Transactions	6 Months Ended
Jun. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Chairman and Chief Executive Officer, the President, the Executive Vice President-Chief Legal and Administrative Officer and the Senior Vice President-Chief Accounting Officer of the Company are also officers of various members of the Saul Organization and their management time is shared with the Saul Organization. Their annual compensation is fixed by the Compensation Committee of the Board of Directors, with the exception of the Senior Vice President-Chief Accounting Officer whose share of annual compensation allocated to the Company is determined by the shared services agreement (described below). The Company participates in a multiemployer 401K plan with entities in the Saul Organization which covers those full-time employees who meet the requirements as specified in the plan. Company contributions, which are included in general and administrative expense or property operating expenses in the Consolidated Statements of Operations, at the discretionary amount of up to six percent of the employee’s cash compensation, subject to certain limits, were $176,100 and $185,500 for the six months ended June 30, 2018 and 2017, respectively. All amounts contributed by employees and the Company are fully vested. The Company also participates in a multiemployer nonqualified deferred compensation plan with entities in the Saul Organization which covers those full-time employees who meet the requirements as specified in the plan. According to the plan, which can be modified or discontinued at any time, participating employees defer 2% of their compensation in excess of a specified amount. For the six months ended June 30, 2018 and 2017, the Company credited to employee accounts $98,600 and $94,400, respectively, which is the sum of accrued earnings and three times the amount deferred by employees and is included in general and administrative expense. All amounts contributed by employees and credited by the Company are fully vested. The cumulative unfunded liability under this plan was $2.5 million and $2.4 million, at June 30, 2018 and December 31, 2017, respectively, and is included in accounts payable, accrued expenses and other liabilities in the Consolidated Balance Sheets. The Company has entered into a shared services agreement (the “Agreement”) with the Saul Organization that provides for the sharing of certain personnel and ancillary functions such as computer hardware, software, and support services and certain direct and indirect administrative personnel. The method for determining the cost of the shared services is provided for in the Agreement and is based upon head count, estimates of usage or estimates of time incurred, as applicable. The terms of the Agreement and the payments made thereunder are deemed reasonable by management and are reviewed annually by the Audit Committee of the Board of Directors, which consists entirely of independent directors. Billings by the Saul Organization for the Company’s share of these ancillary costs and expenses for the six months ended June 30, 2018 and 2017, which included rental expense for the Company’s headquarters lease, totaled approximately $4.1 million and $3.7 million, net, respectively. The amounts are generally expensed as incurred and are primarily reported as general and administrative expenses in the Consolidated Statements of Operations. As of June 30, 2018 and December 31, 2017, accounts payable, accrued expenses and other liabilities included approximately $788,200 and $993,200, respectively, representing amounts due to the Saul Organization for the Company’s share of these ancillary costs and expenses. The Company has entered into a shared third-party predevelopment cost agreement (the “Predevelopment Agreement”) with the Trust. The Predevelopment Agreement relates to the sharing of third-party predevelopment costs incurred in connection with the planning of the future redevelopment of certain adjacent real estate assets in the Twinbrook area of Rockville, Maryland. The costs will be shared on a pro rata basis based on the acreage owned by each entity and neither party is obligated to advance funds to the other. In August 2016, the Company entered into an agreement to acquire from the Trust approximately 13.7 acres of land located at the intersection of Ashburn Village Boulevard and Russell Branch Parkway in Loudoun County, Virginia. The transaction closed on May 9, 2018, and the Company issued 176,680 limited partnership units to the Trust. The Company intends to construct a shopping center and, upon stabilization, may be obligated to issue additional limited partnership units to the Trust. The Company subleases its corporate headquarters space from a member of the Saul Organization. The lease commenced in March 2002, expires in 2022, and provides for base rent increases of 3% per year, with payment of a pro-rata share of operating expenses over a base year amount. The Agreement requires each party to pay an allocation of total rental payments based on a percentage proportionate to the number of employees employed by each party. The Company’s rent expense for its headquarters location was $395,400 and $379,300 for the six months ended June 30, 2018 and 2017, respectively, and is included in general and administrative expense. The B. F. Saul Insurance Agency of Maryland, Inc., a subsidiary of the B. F. Saul Company and a member of the Saul Organization, is a general insurance agency that receives commissions and fees in connection with the Company’s insurance program. Such commissions and fees amounted to $150,500 and $85,700 for the six months ended June 30, 2018 and 2017, respectively.

Related Party Transactions

The Chairman and Chief Executive Officer, the President, the Executive Vice President-Chief Legal and Administrative Officer and the Senior Vice President-Chief Accounting Officer of the Company are also officers of various members of the Saul Organization and their management time is shared with the Saul Organization. Their annual compensation is fixed by the Compensation Committee of the Board of Directors, with the exception of the Senior Vice President-Chief Accounting Officer whose share of annual compensation allocated to the Company is determined by the shared services agreement (described below).

The Company participates in a multiemployer 401K plan with entities in the Saul Organization which covers those full-time employees who meet the requirements as specified in the plan. Company contributions, which are included in general and administrative expense or property operating expenses in the Consolidated Statements of Operations, at the discretionary amount of up to six percent of the employee’s cash compensation, subject to certain limits, were $176,100 and $185,500 for the six months ended June 30, 2018 and 2017, respectively. All amounts contributed by employees and the Company are fully vested.

The Company also participates in a multiemployer nonqualified deferred compensation plan with entities in the Saul Organization which covers those full-time employees who meet the requirements as specified in the plan. According to the plan, which can be modified or discontinued at any time, participating employees defer 2% of their compensation in excess of a specified amount. For the six months ended June 30, 2018 and 2017, the Company credited to employee accounts $98,600 and $94,400, respectively, which is the sum of accrued earnings and three times the amount deferred by employees and is included in general and administrative expense. All amounts contributed by employees and credited by the Company are fully vested. The cumulative unfunded liability under this plan was $2.5 million and $2.4 million, at June 30, 2018 and December 31, 2017, respectively, and is included in accounts payable, accrued expenses and other liabilities in the Consolidated Balance Sheets.

The Company has entered into a shared services agreement (the “Agreement”) with the Saul Organization that provides for the sharing of certain personnel and ancillary functions such as computer hardware, software, and support services and certain direct and indirect administrative personnel. The method for determining the cost of the shared services is provided for in the Agreement and is based upon head count, estimates of usage or estimates of time incurred, as applicable. The terms of the Agreement and the payments made thereunder are deemed reasonable by management and are reviewed annually by the Audit Committee of the Board of Directors, which consists entirely of independent directors. Billings by the Saul Organization for the Company’s share of these ancillary costs and expenses for the six months ended June 30, 2018 and 2017, which included rental expense for the Company’s headquarters lease, totaled approximately $4.1 million and $3.7 million, net, respectively. The amounts are generally expensed as incurred and are primarily reported as general and administrative expenses in the Consolidated Statements of Operations. As of June 30, 2018 and December 31, 2017, accounts payable, accrued expenses and other liabilities included approximately $788,200 and $993,200, respectively, representing amounts due to the Saul Organization for the Company’s share of these ancillary costs and expenses.

The Company has entered into a shared third-party predevelopment cost agreement (the “Predevelopment Agreement”) with the Trust. The Predevelopment Agreement relates to the sharing of third-party predevelopment costs incurred in connection with the planning of the future redevelopment of certain adjacent real estate assets in the Twinbrook area of Rockville, Maryland. The costs will be shared on a pro rata basis based on the acreage owned by each entity and neither party is obligated to advance funds to the other.

In August 2016, the Company entered into an agreement to acquire from the Trust approximately 13.7 acres of land located at the intersection of Ashburn Village Boulevard and Russell Branch Parkway in Loudoun County, Virginia. The transaction closed on May 9, 2018, and the Company issued 176,680 limited partnership units to the Trust. The Company intends to construct a shopping center and, upon stabilization, may be obligated to issue additional limited partnership units to the Trust.

The Company subleases its corporate headquarters space from a member of the Saul Organization. The lease commenced in March 2002, expires in 2022, and provides for base rent increases of 3% per year, with payment of a pro-rata share of operating expenses over a base year amount. The Agreement requires each party to pay an allocation of total rental payments based on a percentage proportionate to the number of employees employed by each party. The Company’s rent expense for its headquarters location was $395,400 and $379,300 for the six months ended June 30, 2018 and 2017, respectively, and is included in general and administrative expense.

The B. F. Saul Insurance Agency of Maryland, Inc., a subsidiary of the B. F. Saul Company and a member of the Saul Organization, is a general insurance agency that receives commissions and fees in connection with the Company’s insurance program. Such commissions and fees amounted to $150,500 and $85,700 for the six months ended June 30, 2018 and 2017, respectively.