Saul Centers (BFS) 10-K6 Mar 152014 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 27, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	BFS
Entity Registrant Name	SAUL CENTERS INC
Entity Central Index Key	907254
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		20,797,898
Entity Public Float			$560.50

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Real estate investments
Land	$420,622	$354,967
Buildings and equipment	1,109,276	1,094,605
Construction in progress	30,261	9,867
Total	1,560,159	1,459,439
Accumulated depreciation	-396,617	-364,663
Real estate investments, net	1,163,542	1,094,776
Cash and cash equivalents	12,128	17,297
Accounts receivable and accrued income, net	46,784	43,884
Deferred leasing costs, net	26,928	26,052
Prepaid expenses, net	4,093	4,047
Deferred debt costs, net	9,874	9,675
Other assets	3,638	2,944
Total assets	1,266,987	1,198,675
Liabilities
Mortgage notes payable	808,997	820,068
Revolving credit facility payable	43,000	0
Construction loan payable	5,391	0
Dividends and distributions payable	14,352	13,135
Accounts payable, accrued expenses and other liabilities	23,537	20,141
Deferred income	32,453	30,205
Total liabilities	927,730	883,549
Preferred stock, 1,000,000 shares authorized:
Common stock, $0.01 par value, 30,000,000 shares authorized, 20,947,141 and 20,576,616 shares issued and outstanding, respectively	209	206
Additional paid-in capital	287,995	270,428
Accumulated deficit	-173,774	-172,564
Accumulated other comprehensive loss	-1,894	-1,392
Total Saul Centers, Inc. stockholders' equity	292,536	276,678
Noncontrolling interests	46,721	38,448
Total stockholders' equity	339,257	315,126
Total liabilities and stockholders' equity	1,266,987	1,198,675
Series A Preferred Stock
Preferred stock, 1,000,000 shares authorized:
Cumulative Redeemable Preferred stock	0	40,000
Series C Preferred Stock
Preferred stock, 1,000,000 shares authorized:
Cumulative Redeemable Preferred stock	$180,000	$140,000

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Preferred stock, shares authorized	1,000,000	1,000,000
Common stock, par value (in usd per share)	$0.01	$0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	20,947,141	20,576,616
Common stock, shares outstanding	20,947,141	20,576,616
Series A Preferred Stock
Cumulative Redeemable Preferred stock, shares issued		16,000
Cumulative Redeemable Preferred stock, shares outstanding		16,000
Series C Preferred Stock
Cumulative Redeemable Preferred stock, shares issued	72,000	56,000
Cumulative Redeemable Preferred stock, shares outstanding	72,000	56,000

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue
Base rent	$164,599	$159,898	$152,777
Expense recoveries	32,132	30,949	30,391
Percentage rent	1,492	1,575	1,545
Other	8,869	5,475	5,379
Total revenue	207,092	197,897	190,092
Operating expenses
Property operating expenses	26,479	24,559	23,794
Provision for credit losses	680	968	1,151
Real estate taxes	22,354	22,415	22,325
Interest expense and amortization of deferred debt costs	46,034	46,589	49,544
Depreciation and amortization of deferred leasing costs	41,203	49,130	40,112
General and administrative	16,961	14,951	14,274
Acquisition related costs	949	106	1,129
Predevelopment expenses	503	3,910	2,667
Total operating expenses	155,163	162,628	154,996
Operating income	51,929	35,269	35,096
Change in fair value of derivatives	-10	-7	36
Loss on early extinguishment of debt	0	-497	0
Gain on sales of properties	6,069	0	0
Gain on casualty settlement	0	77	219
Income from continuing operations	57,988	34,842	35,351
Discontinued operations
Loss from operations of properties sold	0	0	-81
Gain on sales of properties	0	0	4,510
Income from discontinued operations	0	0	4,429
Net Income	57,988	34,842	39,780
Noncontrolling interests
Income from continuing operations attributable to noncontrolling interests	-11,045	-3,970	-5,693
Income from discontinued operations attributable to noncontrolling interests	0	0	-713
Income attributable to noncontrolling interests	-11,045	-3,970	-6,406
Net income attributable to Saul Centers, Inc.	46,943	30,872	33,374
Preferred stock redemption	-1,480	-5,228	0
Preferred dividends	-13,361	-13,983	-15,140
Net income available to common stockholders	$32,102	$11,661	$18,234
Basic:
Continuing operations (in dollars per share)	$1.55	$0.57	$0.70
Discontinued operations (in dollars per share)	$0	$0	$0.23
Basic (in dollars per share)	$1.55	$0.57	$0.93
Diluted:
Continuing operations (in dollars per share)	$1.54	$0.57	$0.70
Discontinued operations (in dollars per share)	$0	$0	$0.23
Diluted (in dollars per share)	$1.54	$0.57	$0.93

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$57,988	$34,842	$39,780
Other comprehensive income
Unrealized gain (loss) on cash flow hedge	-675	2,897	-932
Total comprehensive income	57,313	37,739	38,848
Comprehensive income attributable to noncontrolling interests	-10,874	-4,706	-6,164
Total comprehensive income attributable to Saul Centers, Inc.	46,439	33,033	32,684
Preferred stock redemption	-1,480	-5,228	0
Preferred dividends	-13,361	-13,983	-15,140
Total comprehensive income available to common stockholders	$31,598	$13,822	$17,544

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock	Preferred Stock	Preferred Stock	Preferred Stock	Preferred Stock	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital	Additional Paid-in Capital	Additional Paid-in Capital	Accumulated Deficit	Accumulated Deficit	Accumulated Deficit	Accumulated Other Comprehensive (Loss)	Total Saul Centers, Inc.	Total Saul Centers, Inc.	Total Saul Centers, Inc.	Total Saul Centers, Inc.	Noncontrolling Interest	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Paid	Dividend Declared	Dividend Declared	Dividend Declared	Dividend Declared	Dividend Declared	Dividend Declared	Dividend Declared	Dividend Declared	Dividend Declared	Dividend Declared
In Thousands, unless otherwise specified						Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock			Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock		Series A Preferred Stock	Series B Preferred Stock			Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock			Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock	Accumulated Deficit	Accumulated Deficit	Accumulated Deficit	Accumulated Deficit	Total Saul Centers, Inc.	Total Saul Centers, Inc.	Total Saul Centers, Inc.	Total Saul Centers, Inc.	Noncontrolling Interest		Series A Preferred Stock	Series B Preferred Stock	Accumulated Deficit	Accumulated Deficit	Accumulated Deficit	Total Saul Centers, Inc.	Total Saul Centers, Inc.	Total Saul Centers, Inc.	Noncontrolling Interest
																												Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock		Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock						Series A Preferred Stock	Series B Preferred Stock		Series A Preferred Stock	Series B Preferred Stock
Beginning Balance at Dec. 31, 2011	$293,206				$179,328				$193	$217,829				($144,659)			($2,863)	$249,828				$43,378
Issuance of common stock:
Pursuant to dividend reinvestment plan	23,130								6	23,124								23,130
Exercise of employee stock options and issuance of directors' deferred stock	5,606								2	5,604								5,606
Net income	39,780													33,374				33,374				6,406
Change in unrealized loss on cash flow hedge	-932																-690	-690				-242
Preferred stock distributions:
Preferred stock distributions																								-6,000	-5,355			-6,000	-5,355			-6,000	-5,355				-2,000	-1,785		-2,000	-1,785		-2,000	-1,785
Common stock distributions																							-28,656				-21,189				-21,189				-7,467
Distributions payable preferred stock
Distributions payable common stock and distributions payable partnership units																																				-9,705			-7,216			-7,216			-2,489
Ending Balance at Dec. 31, 2012	307,289				179,328				201	246,557				-154,830			-3,553	267,703				39,586
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares of Series C preferred stock				135,193				140,000					-4,807								135,193
Redemption of preferred stock		-60,004	-79,333			-60,000	-79,328				2,212	3,007			-2,216	-3,012			-60,004	-79,333
Issuance of common stock:
Pursuant to dividend reinvestment plan	20,672								5	20,667								20,672
Exercise of employee stock options and issuance of directors' deferred stock	2,792									2,792								2,792
Issuance of partnership units pursuant to dividend reinvestment plan	4,144																					4,144
Net income	34,842													30,872				30,872				3,970
Change in unrealized loss on cash flow hedge	2,897																2,161	2,161				736
Preferred stock distributions:
Preferred stock distributions																								-3,213	-1,468	-6,095		-3,213	-1,468	-6,095		-3,213	-1,468	-6,095			-800	-2,406		-800	-2,406		-800	-2,406
Common stock distributions																							-29,455				-21,988				-21,988				-7,467
Distributions payable preferred stock
Distributions payable common stock and distributions payable partnership units																																				-9,929			-7,408			-7,408			-2,521
Ending Balance at Dec. 31, 2013	315,126				180,000				206	270,428				-172,564			-1,392	276,678				38,448
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares of Series C preferred stock				39,260				40,000					-740								39,260
Redemption of preferred stock		-40,000				-40,000					1,475				-1,475				-40,000
Issuance of common stock:
Pursuant to dividend reinvestment plan	9,264								2	9,262								9,264
Exercise of employee stock options and issuance of directors' deferred stock	7,571								1	7,570								7,571
Issuance of partnership units pursuant to dividend reinvestment plan	8,877																					8,877
Net income	57,988													46,943				46,943				11,045
Change in unrealized loss on cash flow hedge	-675																-502	-502				-173
Preferred stock distributions:
Preferred stock distributions																								-3,049		-7,219		-3,049		-7,219		-3,049		-7,219				-3,094			-3,094			-3,094
Common stock distributions																							-33,534				-24,937				-24,937				-8,597
Distributions payable preferred stock
Distributions payable common stock and distributions payable partnership units																																				-11,258			-8,379			-8,379			-2,879
Ending Balance at Dec. 31, 2014	$339,257				$180,000				$209	$287,995				($173,774)			($1,894)	$292,536				$46,721

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pursuant to dividend reinvestment plan, shares	197,638	475,162	595,388
Exercise of employee stock options and issuance of directors' deferred stock, shares	172,887	56,002	158,219
Issuance of partnership units pursuant to dividend reinvestment plan, shares	196,183	88,309
Series A Preferred Stock
Redemption of preferred stock, shares	16,000	24,000
Series B Preferred Stock
Redemption of preferred stock, shares		31,731
Series C Preferred Stock
Issuance of common stock, shares	16,000	56,000
Dividend Declared
Distributions payable common stock (in usd per share)	0.4	0.36	0.36
Distributions partnership units (in usd per share)	0.4	0.36	0.36
Dividend Declared \| Series A Preferred Stock
Preferred stock (in usd per share)		50	50
Dividend Declared \| Series B Preferred Stock
Preferred stock (in usd per share)			56.25
Dividend Declared \| Series C Preferred Stock
Preferred stock (in usd per share)	42.97	42.97

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Notes Assumed	$11,000
Cash flows from operating activities:
Net income	57,988		34,842	39,780
Adjustments to reconcile net income to net cash provided by operating activities:
Change in fair value of derivatives	10		7	-36
Gain on sale of property	-6,069		0	-4,510
Gain on casualty settlement	0		-77	-219
Depreciation and amortization of deferred leasing costs	41,203		49,130	40,189
Amortization of deferred debt costs	1,327		1,257	1,576
Non cash compensation costs of stock grants and options	1,240		1,145	952
Provision for credit losses	680		968	1,151
Increase in accounts receivable and accrued income	-3,320		-3,669	-3,240
Additions to deferred leasing costs	-4,048		-5,876	-5,362
Increase in prepaid expenses	-60		-152	-54
(Increase) decrease in other assets	-694		353	9,573
Increase (decrease) in accounts payable, accrued expenses and other liabilities	1,149		-3,286	-930
Decrease in deferred income	-2,838		-1,115	-447
Net cash provided by operating activities	86,568		73,527	78,423
Cash flows from investing activities:
Acquisitions of real estate investments	-57,494	[1]	-5,124	-34,050
Additions to real estate investments	-14,986		-13,999	-12,680
Additions to development and redevelopment projects	-17,788		-7,316	-7,913
Proceeds from sale of properties	6,679		0	5,818
Proceeds from casualty settlement	0		405	1,952
Net cash used in investing activities	-83,589		-26,034	-46,873
Cash flows from financing activities:
Proceeds from mortgage notes payable (1)	0	[1]	101,600	83,500
Repayments on mortgage notes payable	-22,071		-71,308	-117,595
Proceeds from construction loans payable	5,391		0	0
Proceeds from revolving credit facility	90,000		142,000	38,000
Repayments on revolving credit facility	-47,000		-180,000	-8,000
Additions to deferred debt costs	-1,264		-3,219	-2,199
Proceeds from the issuance of:
Common stock	15,596		22,292	27,784
Partnership units	8,877		4,144	0
Preferred stock redemption costs	0		-9	0
Distributions to:
Preferred stockholders	-13,474		-14,561	-15,140
Common stockholders	-32,346		-29,205	-28,135
Noncontrolling interests	-11,117		-9,956	-9,955
Net cash used in financing activities	-8,148		-42,329	-31,740
Net increase (decrease) in cash and cash equivalents	-5,169		5,164	-190
Cash and cash equivalents, beginning of year	17,297		12,133	12,323
Cash and cash equivalents, end of year	12,128		17,297	12,133
Supplemental disclosure of cash flow information:
Cash paid for interest	45,443		45,743	48,302
Series C Preferred Stock
Proceeds from the issuance of:
Series C preferred stock	39,260		135,221	0
Distributions to:
Preferred stockholders	-9,625		-6,095	0
Series A Preferred Stock
Proceeds from the issuance of:
Preferred stock redemption payments	-40,000		-60,000	0
Distributions to:
Preferred stockholders	-3,849		-5,213	-8,000
Series B Preferred Stock
Proceeds from the issuance of:
Preferred stock redemption payments	0		-79,328	0
Distributions to:
Preferred stockholders	$0		($3,253)	($7,140)

[1]	The 2014 acquisition of real estate and proceeds from notes payable each exclude $11,000 in connection with the sale and leaseback of the Company's Olney property.

Organization_Formation_and_Bas

Organization, Formation, and Basis of Presentation	12 Months Ended
Organization, Formation, and Basis of Presentation	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Formation, and Basis of Presentation	ORGANIZATION, FORMATION, AND BASIS OF PRESENTATION
	Organization
	Saul Centers, Inc. (“Saul Centers”) was incorporated under the Maryland General Corporation Law on June 10, 1993. Saul Centers operates as a real estate investment trust (a “REIT”) under the Internal Revenue Code of 1986, as amended (the “Code”). The Company is required to annually distribute at least 90% of its REIT taxable income (excluding net capital gains) to its stockholders and meet certain organizational and other requirements. Saul Centers has made and intends to continue to make regular quarterly distributions to its stockholders. Saul Centers, together with its wholly owned subsidiaries and the limited partnerships of which Saul Centers or one of its subsidiaries is the sole general partner, are referred to collectively as the “Company.” B. Francis Saul II serves as Chairman of the Board of Directors and Chief Executive Officer of Saul Centers.
	Formation and Structure of Company
	Saul Centers was formed to continue and expand the shopping center business previously owned and conducted by the B. F. Saul Real Estate Investment Trust, the B. F. Saul Company and certain other affiliated entities, each of which is controlled by B. Francis Saul II and his family members (collectively, the “Saul Organization”). On August 26, 1993, members of the Saul Organization transferred to Saul Holdings Limited Partnership, a newly formed Maryland limited partnership (the “Operating Partnership”), and two newly formed subsidiary limited partnerships (the “Subsidiary Partnerships,” and collectively with the Operating Partnership, the “Partnerships”), shopping center and mixed-used properties, and the management functions related to the transferred properties. Since its formation, the Company has developed and purchased additional properties.
	The following table lists the significant properties acquired, developed and/or disposed of by the Company since January 1, 2012.



	Name of Property	Location	Type	Year of
				Acquisition/
				Development/
				Disposal
	Acquisitions
	1500 Rockville Pike	Rockville, Maryland	Shopping Center	Dec-12
	5541 Nicholson Lane	Rockville, Maryland	Shopping Center	Dec-12
	1580 Rockville Pike	Rockville, Maryland	Shopping Center	Jan-14
	1582 Rockville Pike	Rockville, Maryland	Shopping Center	Apr-14
	750 N. Glebe Road	Arlington, Virginia	Shopping Center	Aug-14
	730 N. Glebe Road	Arlington, Virginia	Shopping Center	Dec-14
	1584 Rockville Pike	Rockville, Maryland	Shopping Center	Dec-14

	Developments
	Park Van Ness	Washington, DC	Mixed-Use	2013/2014

	Dispositions
	West Park	Oklahoma City, Oklahoma	Shopping Center	Jul-12
	Belvedere	Baltimore, Maryland	Shopping Center	Dec-12
	Giant Center	Milford Mill, Maryland	Shopping Center	Apr-14
	As of December 31, 2014, the Company’s properties (the “Current Portfolio Properties”) consisted of 50 shopping center properties (the “Shopping Centers”), six mixed-use properties which are comprised of office, retail and multi-family residential uses (the “Mixed-Use Properties”) and three (non-operating) development properties.

	Basis of Presentation
	The accompanying financial statements are presented on the historical cost basis of the Saul Organization because of affiliated ownership and common management and because the assets and liabilities were the subject of a business combination with the Operating Partnership, the Subsidiary Partnerships and Saul Centers, all newly formed entities with no prior operations.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Nature of Operations
	The Company, which conducts all of its activities through its subsidiaries, the Operating Partnership and Subsidiary Partnerships, engages in the ownership, operation, management, leasing, acquisition, renovation, expansion, development and financing of community and neighborhood shopping centers and mixed-used properties, primarily in the Washington, DC/Baltimore metropolitan area. Because the properties are located primarily in the Washington, DC/Baltimore metropolitan area, a disproportionate economic downturn in the local economy would have a greater negative impact on our overall financial performance than on the overall financial performance of a company with a portfolio that is more geographically diverse. A majority of the Shopping Centers are anchored by several major tenants. As of December 31, 2014, 32 of the Shopping Centers were anchored by a grocery store and offer primarily day-to-day necessities and services. Two retail tenants, Giant Food (4.5%), a tenant at nine Shopping Centers, and Safeway (2.5%), a tenant at eight Shopping Centers, individually accounted for 2.5% or more of the Company’s total revenue for the year ended December 31, 2014.
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of Saul Centers, its subsidiaries, and the Operating Partnership and Subsidiary Partnerships which are majority owned by Saul Centers. All significant intercompany balances and transactions have been eliminated in consolidation.
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
	Real Estate Investment Properties
	The Company purchases real estate investment properties from time to time and records assets acquired and liabilities assumed, including land, buildings, and intangibles related to in-place leases and customer relationships, based on their fair values. The fair value of buildings generally is determined as if the buildings were vacant upon acquisition and then subsequently leased at market rental rates and considers the present value of all cash flows expected to be generated by the property including an initial lease up period. From time to time the Company may purchase a property for future development purposes. The property may be improved with an existing structure that would be demolished as part of the development. In such cases, the fair value of the building may be determined based only on existing leases and not include estimated cash flows related to future leases. In certain circumstances, such as if the building is vacant and the Company intends to demolish the building in the near term, the entire purchase price will be allocated to land.
	The Company determines the fair value of above and below market intangibles associated with in-place leases by assessing the net effective rent and remaining term of the lease relative to market terms for similar leases at acquisition taking into consideration the remaining contractual lease period, renewal periods, and the likelihood of the tenant exercising its renewal options. The fair value of a below market lease component is recorded as deferred income and accreted as additional lease revenue over the remaining contractual lease period. If the fair value of the below market lease intangible includes fair value associated with a renewal option, such amounts are not accreted until the renewal option is exercised. If the renewal option is not exercised the value is recognized at that time. The fair value of above market lease intangibles is recorded as a deferred asset and is amortized as a reduction of lease revenue over the remaining contractual lease term. The Company determines the fair value of at-market in-place leases considering the cost of acquiring similar leases, the foregone rents associated with the lease-up period and carrying costs associated with the lease-up period. Intangible assets associated with at-market in-place leases are amortized as additional expense over the remaining contractual lease term. To the extent customer relationship intangibles are present in an acquisition, the fair values of the intangibles are amortized over the lives of the customer relationships. The Company has never recorded a customer relationship intangible asset. Acquisition-related transaction costs are either (a) expensed as incurred when related to business combinations or (b) capitalized to land and/or building when related to asset acquisitions.
	If there is an event or change in circumstance that indicates a potential impairment in the value of a real estate investment property, the Company prepares an analysis to determine whether the carrying value of the real estate investment property exceeds its estimated fair value. The Company considers both quantitative and qualitative factors including recurring operating losses, significant decreases in occupancy, and significant adverse changes in legal factors and business climate. If impairment indicators are present, the Company compares the projected cash flows of the property over its remaining useful life, on an undiscounted basis, to the carrying value of that property. The Company assesses its undiscounted projected cash flows based upon estimated capitalization rates, historic operating results and market conditions that may affect the property. If the carrying value is greater than the undiscounted projected cash flows, the Company would recognize an impairment loss equivalent to an amount required to adjust the carrying amount to its then estimated fair value. The fair value of any property is sensitive to the actual results of any of the aforementioned estimated factors, either individually or taken as a whole. Should the actual results differ from management’s projections, the valuation could be negatively or positively affected. The Company did not recognize an impairment loss on any of its real estate in 2014, 2013, or 2012.
	Interest, real estate taxes, development related salary costs and other carrying costs are capitalized on projects under development and construction. Once construction is substantially completed and the assets are placed in service, their rental income, real estate tax expense, property operating expenses (consisting of payroll, repairs and maintenance, utilities, insurance and other property related expenses) and depreciation are included in current operations. Property operating expenses are charged to operations as incurred. Interest expense capitalized totaled $688,900, $170,000, and $42,300 during 2014, 2013, and 2012, respectively. Commercial development projects are considered substantially complete and available for occupancy upon completion of tenant improvements, but no later than one year from the cessation of major construction activity. Multi-family residential development projects are considered substantially complete and available for occupancy upon receipt of the certificate of occupancy from the appropriate licensing authority. Substantially completed portions of a project are accounted for as separate projects.
	Depreciation is calculated using the straight-line method and estimated useful lives of generally between 35 and 50 years for base buildings, or a shorter period if management determines that the building has a shorter useful life, and up to 20 years for certain other improvements that extend the useful lives. Leasehold improvements expenditures are capitalized when certain criteria are met, including when the Company supervises construction and will own the improvements. Tenant improvements are amortized, over the shorter of the lives of the related leases or the useful life of the improvement, using the straight-line method. Depreciation expense and amortization of leasehold improvements, which is included in Depreciation and amortization of deferred leasing costs in the Consolidated Statements of Operations, for the years ended December 31, 2014, 2013, and 2012, was $35.9 million, $43.2 million, and $34.6 million, respectively. Repairs and maintenance expense totaled $11.9 million, $10.3 million, and $9.9 million for 2014, 2013, and 2012, respectively, and is included in property operating expenses in the accompanying consolidated financial statements.
	Deferred Leasing Costs
	Deferred leasing costs consist of commissions paid to third-party leasing agents, internal direct costs such as employee compensation and payroll-related fringe benefits directly related to time spent performing leasing-related activities for successful commercial leases and amounts attributed to in place leases associated with acquired properties and are amortized, using the straight-line method, over the term of the lease or the remaining term of an acquired lease. Leasing related activities include evaluating the prospective tenant’s financial condition, evaluating and recording guarantees, collateral and other security arrangements, negotiating lease terms, preparing lease documents and closing the transaction. Unamortized deferred costs are charged to expense if the applicable lease is terminated prior to expiration of the initial lease term. Collectively, deferred leasing costs totaled $26.9 million and $26.1 million, net of accumulated amortization of approximately $21.6 million and $16.6 million, as of December 31, 2014 and 2013, respectively. Amortization expense, which is included in Depreciation and amortization of deferred leasing costs in the Consolidated Statements of Operations, totaled approximately $5.3 million, $5.9 million, and $5.5 million, for the years ended December 31, 2014, 2013, and 2012, respectively.

	Construction in Progress
	Construction in progress includes preconstruction and development costs of active projects. Preconstruction costs include legal, zoning and permitting costs and other project carrying costs incurred prior to the commencement of construction. Development costs include direct construction costs and indirect costs incurred subsequent to the start of construction such as architectural, engineering, construction management and carrying costs consisting of interest, real estate taxes and insurance. The following table shows the components of construction in progress.


			December 31,
	(in thousands)		2014				2013

	Park Van Ness		$	26,998			$	7,901

	Other		3,263				1,966

	Total		$	30,261			$	9,867


	Accounts Receivable and Accrued Income
	Accounts receivable primarily represent amounts currently due from tenants in accordance with the terms of the respective leases. Receivables are reviewed monthly and reserves are established with a charge to current period operations when, in the opinion of management, collection of the receivable is doubtful. Accounts receivable in the accompanying consolidated financial statements are shown net of an allowance for doubtful accounts of $0.7 million and $0.6 million, at December 31, 2014 and 2013, respectively.



	(In thousands)	Year ended December 31,
		2014				2013				2012
	Beginning Balance	$	572			$	1,208			$	671

	Provision for Credit Losses	680				968				1,160

	Charge-offs	(575		)		(1,604		)		(623		)
	Ending Balance	$	677			$	572			$	1,208

	In addition to rents due currently, accounts receivable also includes $38.7 million and $37.2 million, at December 31, 2014 and 2013, respectively, net of allowance for doubtful accounts totaling $0.3 million and $0.5 million, respectively, representing minimum rental income accrued on a straight-line basis to be paid by tenants over the remaining term of their respective leases.
	Cash and Cash Equivalents
	Cash and cash equivalents include short-term investments. Short-term investments include money market accounts and other investments which generally mature within three months, measured from the acquisition date, and/or are readily convertible to cash. Substantially all of the Company’s cash balances at December 31, 2014 are held in non-interest bearing accounts at various banks. From time to time the Company may maintain deposits with financial institutions in amounts in excess of federally insured limits. The Company has not experienced any losses on such deposits and believes it is not exposed to any significant credit risk on those deposits.
	Deferred Debt Costs
	Deferred debt costs consist of fees and costs incurred to obtain long-term financing, construction financing and the revolving line of credit. These fees and costs are being amortized on a straight-line basis over the terms of the respective loans or agreements, which approximates the effective interest method. Deferred debt costs totaled $9.9 million and $9.7 million, net of accumulated amortization of $5.9 million and $4.5 million at December 31, 2014 and 2013, respectively.
	Deferred Income
	Deferred income consists of payments received from tenants prior to the time they are earned and recognized by the Company as revenue, including tenant prepayment of rent for future periods, real estate taxes when the taxing jurisdiction has a fiscal year differing from the calendar year reimbursements specified in the lease agreement and tenant construction work provided by the Company. In addition, deferred income includes the fair value of certain below market leases.
	Derivative Financial Instruments
	The Company may, when appropriate, employ derivative instruments, such as interest-rate swaps, to mitigate the risk of interest rate fluctuations. The Company does not enter into derivative or other financial instruments for trading or speculative purposes. Derivative financial instruments are carried at fair value as either assets or liabilities on the consolidated balance sheets. For those derivative instruments that qualify, the Company may designate the hedging instrument, based upon the exposure being hedged, as a fair value hedge or a cash flow hedge. Derivative instruments that are designated as a hedge are evaluated to ensure they continue to qualify for hedge accounting. The effective portion of any gain or loss on the hedge instruments is reported as a component of accumulated other comprehensive income (loss) and recognized in earnings within the same line item associated with the forecasted transaction in the same period or periods during which the hedged transaction affects earnings. Any ineffective portion of the change in fair value of a derivative instrument is immediately recognized in earnings. For derivative instruments that do not meet the criteria for hedge accounting, or that qualify and are not designated, changes in fair value are immediately recognized in earnings.
	Discontinued Operations
	During 2012, the Company sold its West Park and Belvedere properties for $2.0 million and $4.0 million and recognized gains of $1.1 million and $3.4 million, respectively. The results of operations of West Park and Belvedere for the year ended December 31, 2012 are included in the statements of operations as “Loss from operations of properties sold.” The 2014 sale of Giant Center is accounted for under the new discontinued operations guidance discussed below in Recently Issued Accounting Standards and, therefore, is not presented as discontinued operations.
	Revenue Recognition
	Rental and interest income are accrued as earned except when doubt exists as to collectability, in which case the accrual is discontinued. Recognition of rental income commences when control of the space has been given to the tenant. When rental payments due under leases vary from a straight-line basis because of free rent periods or stepped increases, income is recognized on a straight-line basis. Expense recoveries represent a portion of property operating expenses billed to the tenants, including common area maintenance, real estate taxes and other recoverable costs. Expense recoveries are recognized in the period in which the expenses are incurred. Rental income based on a tenant’s revenue (“percentage rent”) is accrued when a tenant reports sales that exceed a specified breakpoint, pursuant to the terms of their respective leases.
	Income Taxes
	The Company made an election to be treated, and intends to continue operating so as to qualify, as a REIT under the Code, commencing with its taxable year ended December 31, 1993. A REIT generally will not be subject to federal income taxation, provided that distributions to its stockholders equal or exceed its REIT taxable income and complies with certain other requirements. Therefore, no provision has been made for federal income taxes in the accompanying consolidated financial statements.
	As of December 31, 2014, the Company had no material unrecognized tax benefits and there exist no potentially significant unrecognized tax benefits which are reasonably expected to occur within the next twelve months. The Company recognizes penalties and interest accrued related to unrecognized tax benefits, if any, as general and administrative expense. No penalties and interest have been accrued in years 2014, 2013, and 2012. The tax basis of the Company’s real estate investments was approximately $1.2 billion and $1.1 billion as of December 31, 2014 and 2013, respectively. With few exceptions, the Company is no longer subject to U.S. federal, state, and local tax examinations by tax authorities for years before 2008.
	Stock Based Employee Compensation, Deferred Compensation and Stock Plan for Directors
	The Company uses the fair value method to value and account for employee stock options. The fair value of options granted is determined at the time of each award using the Black-Scholes model, a widely used method for valuing stock based employee compensation, and the following assumptions: (1) Expected Volatility determined using the most recent trading history of the Company’s common stock (month-end closing prices) corresponding to the average expected term of the options; (2) Average Expected Term of the options is based on prior exercise history, scheduled vesting and the expiration date; (3) Expected Dividend Yield determined by management after considering the Company’s current and historic dividend yield rates, the Company’s yield in relation to other retail REITs and the Company’s market yield at the grant date; and (4) a Risk-free Interest Rate based upon the market yields of US Treasury obligations with maturities corresponding to the average expected term of the options at the grant date. The Company amortizes the value of options granted ratably over the vesting period and includes the amounts as compensation in general and administrative expenses.
	The Company has a stock plan, which was originally approved in 2004, amended in 2008 and 2013 and which expires in 2023, for the purpose of attracting and retaining executive officers, directors and other key personnel (the "Stock Plan"). Pursuant to the Stock Plan, the Compensation Committee established a Deferred Compensation Plan for Directors for the benefit of its directors and their beneficiaries, which replaced a previous Deferred Compensation and Stock Plan for Directors. A director may make an annual election to defer all or part of his or her director’s fees and has the option to have the fees paid in cash, in shares of common stock or in a combination of cash and shares of common stock upon separation from the Board. If the director elects to have fees paid in stock, fees earned during a calendar quarter are aggregated and divided by the common stock’s closing market price on the first trading day of the following quarter to determine the number of shares to be allocated to the director. As of December 31, 2014, the directors’ deferred fee accounts comprise 232,262 shares.
	The Compensation Committee has also approved an annual award of shares of the Company’s common stock as additional compensation to each director serving on the Board of Directors as of the record date for the Annual Meeting of Stockholders. The shares are awarded as of each Annual Meeting of Shareholders, and their issuance may not be deferred. Each director was issued 200 shares for each of the years ended December 31, 2014, 2013, and 2012. The shares were valued at the closing stock price on the dates the shares were awarded and included in general and administrative expenses in the total amounts of $112,900, $124,400, and $110,000, for the years ended December 31, 2014, 2013, and 2012, respectively.
Noncontrolling Interest
Saul Centers is the sole general partner of the Operating Partnership, owning a 74.2% common interest as of December 31, 2014. Noncontrolling interest in the Operating Partnership is comprised of limited partnership units owned by the Saul Organization. Noncontrolling interest reflected on the accompanying consolidated balance sheets is increased for earnings allocated to limited partnership interests and distributions reinvested in additional units, and is decreased for limited partner distributions. Noncontrolling interest reflected on the consolidated statements of operations represents earnings allocated to limited partnership interests held by the Saul Organization.
Per Share Data
Per share data for net income (basic and diluted) is computed using weighted average shares of common stock. Convertible limited partnership units and employee stock options are the Company’s potentially dilutive securities. For all periods presented, the convertible limited partnership units are anti-dilutive. For the years ended December 31, 2014, 2013, and 2012, options totaling 106,875, 112,500, and 117,500, respectively, are not dilutive because the average share price of the Company’s common stock was less than the exercise prices. The treasury stock method was used to measure the effect of the dilution.



	December 31,
(Shares in thousands)	2014				2013				2012
Weighted average common shares outstanding - Basic	20,772				20,364				19,649

Effect of dilutive options	49				37				51

Weighted average common shares outstanding - Diluted	20,821				20,401				19,700

Average share price	$	49.09			$	45.44			$	40.94

Legal Contingencies
The Company is subject to various legal proceedings and claims that arise in the ordinary course of business, which are generally covered by insurance. Upon determination that a loss is probable to occur and can be reasonably estimated, the estimated amount of the loss is recorded in the financial statements.

Recently Issued Accounting Standards
In April 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-08, “Presentation of Financial Statements (Topic 205) and Property Plant and Equipment (Topic 360)” (“ASU 2014-08”). ASU 2014-08 changes the requirements for reporting discontinued operations such that disposals of components of an entity will be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations. ASU 2014-08 also requires additional disclosures about discontinued operations. ASU 2014-08 is effective for annual periods beginning after December 15, 2014, and interim periods within those years and early adoption is permitted. The Company retrospectively adopted ASU 2014-08 on April 15, 2014. The adoption of ASU 2014-08 did not have a material impact on the Company’s financial condition or results of operations.
In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”). ASU 2014-09 will replace most existing revenue recognition guidance and will require an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. ASU 2014-09 is effective for annual periods beginning after December 15, 2016, and interim periods within those years and early adoption is not permitted. ASU 2014-09 must be applied retrospectively by either restating prior periods or by recognizing the cumulative effect as of the first date of application. We have not yet selected a transition method and are evaluating the impact that ASU 2014-09 will have on our consolidated financial statements and related disclosures.

Reclassifications
Certain reclassifications have been made to prior years to conform to the presentation used for year ended December 31, 2014.

Real_Estate_Acquired

Real Estate Acquired	12 Months Ended
	Dec. 31, 2014
Real Estate [Abstract]
Real Estate Acquired	REAL ESTATE ACQUIRED
	1500, 1580, 1582 and 1584 Rockville Pike
	In December 2012, the Company purchased for $22.4 million 1500 Rockville Pike, and incurred acquisition costs of $0.6 million. In January 2014, the Company purchased for $8.0 million 1580 Rockville Pike and incurred acquisition costs of $0.2 million. In April 2014, the Company purchased for $11.0 million 1582 Rockville Pike and incurred acquisition costs of $0.2 million. In December 2014, the company purchased for $6.2 million 1584 Rockville Pike and incurred acquisition costs of $0.2 million. These retail properties are contiguous with each other and are located in Rockville, Maryland.
	730 and 750 Glebe Road
	In August 2014, the Company purchased for $40.0 million, 750 N. Glebe Road and incurred acquisition costs of $0.4 million. In December 2014, the Company purchased for $2.8 million 730 N. Glebe Road, and incurred acquisition costs of $40,400. These retail properties are contiguous and are located in Arlington, Virginia.
	5541 Nicholson Lane
	In December 2012, the Company purchased for $11.7 million 5541 Nicholson Lane, a retail property located in Rockville, Maryland, and incurred acquisition costs of $0.5 million.
	Kentlands pad
	In August 2013, the Company purchased for $4.3 million, a retail pad with a 7,100 square foot restaurant located in Gaithersburg, Maryland, which is contiguous with and an expansion of the Company's other Kentlands assets, and incurred acquisition costs of $106,000.
	Hunt Club pad
	In December 2013, the Company purchased for $0.8 million, including acquisition costs, a retail pad with a 5,500 square foot vacant building located in Apopka, Florida, which is contiguous with and an expansion of the Company's other Hunt Club asset.
	Allocation of Purchase Price of Real Estate Acquired
	The Company allocates the purchase price of real estate investment properties to various components, such as land, buildings and intangibles related to in-place leases and customer relationships, based on their fair values. See Note 2. Summary of Significant Accounting Policies-Real Estate Investment Properties.
	During 2014, the Company purchased five properties at an aggregate cost of $68.0 million, and incurred acquisition costs of $0.9 million. The purchase prices were allocated to the assets acquired and liabilities assumed based on their fair value as shown in the following table.


	(in thousands)	1580			1582			750 N.		730 N.		1584			Total
		Rockville Pike			Rockville Pike			Glebe Road		Glebe Road		Rockville Pike
	Land	$	9,600		$	9,742		$	38,224	$	2,683	$	5,798		$	66,047

	Buildings	2,200			828			1,327		78		440			4,873

	In-place Leases	513			849			449		39		249			2,099

	Above Market Rent	—			—			—		—		—			—

	Below Market Rent	(4,313		)	(419		)	—		—		(337		)	(5,069		)

	Total Purchase Price	$	8,000		$	11,000		$	40,000	$	2,800	$	6,150		$	67,950



	During 2013, the Company purchased two properties at a cost of $5.1 million and incurred acquisition costs of $106,000. Of the total purchase price, $2.0 million was allocated to buildings and $3.1 million was allocated to land. No amounts were allocated to in-place, above-market, or below-market leases.
	During 2012, the Company purchased two properties at an aggregate cost of $34.1 million and incurred acquisition costs of $1.1 million. Of the total purchase price, $3.8 million was allocated to buildings, $30.4 million was allocated to land, and $0.5 million was allocated to in-place leases and $0.7 million was allocated to below market leases which is included in deferred income and is being accreted to income over the lives of the underlying leases, which is approximately 3.1 years.
	The gross carrying amount of lease intangible assets included in deferred leasing costs as of December 31, 2014 and 2013 was $24.0 million and $21.9 million, respectively, and accumulated amortization was $18.0 million and $16.7 million, respectively. Amortization expense totaled $1.3 million, $2.0 million and $2.0 million, for the years ended December 31, 2014, 2013, and 2012, respectively. The gross carrying amount of below market lease intangible liabilities included in deferred income as of December 31, 2014 and 2013 was $29.9 million and $24.8 million, respectively, and accumulated amortization was $11.9 million and $10.0 million, respectively. Accretion income totaled $1.9 million, $1.7 million, and $1.6 million, for the years ended December 31, 2014, 2013, and 2012, respectively. The gross carrying amount of above market lease intangible assets included in accounts receivable as of December 31, 2014 and 2013 was $1.0 million and $1.0 million, respectively, and accumulated amortization was $996,700 and $974,100, respectively. Amortization expense totaled $23,000, $45,000 and $60,000, for the years ended December 31, 2014, 2013 and 2012, respectively.
	As of December 31, 2014, scheduled amortization of intangible assets and deferred income related to in place leases is as follows:


	(In thousands)	Lease acquisition costs			Above market leases			Below market leases
	2015	$	1,252		$	2		$	1,787

	2016	988			1			1,722

	2017	796			1			1,701

	2018	737			1			1,617

	2019	550			—			1,473

	Thereafter	1,739			—			9,670

	Total	$	6,062		$	5		$	17,970

Noncontrolling_Interest_Holder

Noncontrolling Interest - Holders of Convertible Limited Partnership Units in the Operating Partnership	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Noncontrolling Interest - Holders of Convertible Limited Partnership Units in the Operating Partnership	NONCONTROLLING INTEREST - HOLDERS OF CONVERTIBLE LIMITED PARTNERSHIP UNITS IN THE OPERATING PARTNERSHIP
	The Saul Organization holds a 25.8% limited partnership interest in the Operating Partnership represented by 7,198,721 limited partnership units, as of December 31, 2014. The units are convertible into shares of Saul Centers’ common stock, at the option of the unit holder, on a one-for-one basis provided that, in accordance with the Saul Centers, Inc. Articles of Incorporation, the rights may not be exercised at any time that the Saul Organization beneficially owns, directly or indirectly, in the aggregate more than 39.9% of the value of the outstanding common stock and preferred stock of Saul Centers (the “Equity Securities”). As of December 31, 2014, 814,000 units were eligible for conversion.
	The impact of the Saul Organization’s 25.8% limited partnership interest in the Operating Partnership is reflected as Noncontrolling Interest in the accompanying consolidated financial statements. Fully converted partnership units and diluted weighted average shares outstanding for the years ended December 31, 2014, 2013, and 2012, were 27,977,500, 27,330,100, and 26,613,900, respectively.

Mortgage_Notes_Payable_Revolvi

Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs	MORTGAGE NOTES PAYABLE, REVOLVING CREDIT FACILITY, INTEREST EXPENSE AND AMORTIZATION OF DEFERRED DEBT COSTS
	At December 31, 2014, outstanding debt totaled $857.4 million, of which $784.8 million was fixed rate debt and $72.6 million was variable rate debt. The Company’s outstanding debt totaled $820.1 million at December 31, 2013, of which $789.9 million was fixed rate debt and $30.2 million was variable rate debt. At December 31, 2014, the Company had a $275.0 million unsecured revolving credit facility, which can be used for working capital, property acquisitions or development projects. The revolving credit facility matures on June 23, 2018, and may be extended by the Company for one additional year subject to the Company’s satisfaction of certain conditions. Saul Centers and certain consolidated subsidiaries of the Operating Partnership have guaranteed the payment obligations of the Operating Partnership under the revolving credit facility. Letters of credit may be issued under the revolving credit facility. On December 31, 2014, based on the value of the Company's unencumbered properties, approximately $231.6 million was available under the line, $43.0 million was outstanding and approximately $448,000 was committed for letters of credit. The interest rate under the facility is variable and equals the sum of one-month LIBOR and a margin that is based on the Company’s leverage ratio and which can range from 145 basis points to 200 basis points. As of December 31, 2014, the margin was 145 basis points.
	Saul Centers is a guarantor of the revolving credit facility, of which the Operating Partnership is the borrower. Saul Centers guarantees a portion of the Northrock bank term loan (approximately $7.5 million of the $14.5 million outstanding at December 31, 2014) and the Metro Pike Center bank loan (approximately $7.8 million of the $15.1 million outstanding at December 31, 2014) and all of the Park Van Ness construction-to-permanent loan. All other notes payable are non-recourse.
	On April 11, 2012, the Company closed on a 15-year non-recourse mortgage loan in the amount of $73.0 million secured by Seven Corners shopping center. The loan matures in 2027, bears interest at a fixed rate of 5.84%, requires equal monthly principal and interest payments totaling $463,200 based upon a 25-year amortization schedule and a final payment of $42.3 million at maturity. Proceeds from the loan were used to pay-off the $63 million remaining balance of existing debt secured by Seven Corners and six other shopping center properties, and to provide cash of approximately $10 million.
	On April 26, 2012, the Company substituted the White Oak shopping center for Van Ness Square as collateral for one of its existing mortgage loans. The terms of the original loan, including its 8.11% interest rate, are unchanged and, in conjunction with the collateral substitution, the Company borrowed an additional $10.5 million, also secured by White Oak. The new borrowing requires equal monthly payments based upon a fixed 4.90% interest rate and 25-year amortization schedule, and will mature in 2024, coterminously with the original loan. The consolidated loan requires equal monthly payments based upon a blended fixed interest rate of 7.0% and will require a final payment of $18.5 million at maturity.
	On February 27, 2013, the Company closed on a three-year $15.6 million mortgage loan secured by Metro Pike Center. The loan matures in 2016, bears interest at a variable rate equal to the sum of one-month LIBOR and 165 basis points, requires monthly principal and interest payments based on a 25-year amortization schedule and requires a final payment of $14.8 million at maturity. The loan may be extended for up to two years. Proceeds were used to pay-off the $15.9 million remaining balance of existing debt secured by Metro Pike Center, and to extinguish the related swap agreement.
	On February 27, 2013, the Company closed on a three-year $15.0 million mortgage loan secured by Northrock. The loan matures in 2016, bears interest at a variable rate equal to the sum of one-month LIBOR and 165 basis points, requires monthly principal and interest payments based on a 25-year amortization schedule and requires a final payment of $14.2 million at maturity. The loan may be extended for up to two years. Proceeds were used to pay-off the $15.0 million remaining balance of existing debt secured by Northrock.
	On March 19, 2013, the Company closed on a 15-year, non-recourse $18.0 million mortgage loan secured by Hampshire Langley. The loan matures in 2028, bears interest at a fixed rate of 4.04%, requires monthly principal and interest payments totaling $95,400 based on a 25-year amortization schedule and requires a final payment of $9.5 million at maturity.
	On April 10, 2013, the Company paid in full the $6.9 million remaining balance on the mortgage loan secured by Cruse Marketplace.
	On May 28, 2013, the Company closed on a 15-year, non-recourse $35.0 million mortgage loan secured by Beacon Center. The loan matures in 2028, bears interest at a fixed rate of 3.51%, requires monthly principal and interest payments totaling $203,200 based on a 20-year amortization schedule and requires a final payment of $11.4 million at maturity.
	On September 4, 2013, the Company closed on a 15-year, non-recourse $18.0 million mortgage loan secured by Seabreeze Plaza. The loan matures in 2028, bears interest at a fixed rate of 3.99%, requires monthly principal and interest payments totaling $94,900 based on a 25-year amortization schedule and requires a final payment of $9.5 million at maturity. Proceeds were used to pay off the $13.5 million remaining balance of existing debt secured by Seabreeze Plaza which was scheduled to mature in May 2014 and the Company incurred $497,000 of related debt extinguishment costs.
	On October 25, 2013 the Company closed on a $71.6 million construction-to-permanent loan which will partially finance the construction of Park Van Ness. The loan bears interest at 4.88% and during the construction period it will be fully recourse to Saul Centers and accrued interest will be funded by the loan. Following the completion of construction and lease-up, and upon achieving certain debt service coverage requirements, the loan will convert to a non-recourse, permanent mortgage at the same interest rate, with principal amortization computed based on a 25-year schedule.
	On June 24, 2014, the Company amended and restated its revolving credit facility. The Company unsecured revolving credit facility, which can be used for working capital, property acquisitions, development projects or letters of credit was increased to $275.0 million. The revolving credit facility matures on June 23, 2018, and may be extended by the Company for one additional year subject to the Company’s satisfaction of certain conditions. Saul Centers and certain consolidated subsidiaries of the Operating Partnership have guaranteed the payment obligations of the Operating Partnership under the revolving credit facility. Letters of credit may be issued under the revolving credit facility. The interest rate under the facility is variable and equals the sum of one-month LIBOR and a margin that is based on the Company’s leverage ratio, and which can range from 145 basis points to 200 basis points.




	The following is a summary of notes payable as of December 31, 2014 and 2013:



	Notes Payable	December 31,										Interest			Scheduled
	(Dollars in thousands)	2014						2013				Rate *			Maturity *
	Fixed rate mortgages:	$	15,399			(a)		$	16,128			7.45	%		Jun-15

		32,049				(b)		33,246				6.01	%		Feb-18

		35,398				(c)		36,937				5.88	%		Jan-19

		11,454				(d)		11,949				5.76	%		May-19

		15,819				(e)		16,501				5.62	%		Jul-19

		15,761				(f)		16,419				5.79	%		Sep-19

		14,014				(g)		14,610				5.22	%		Jan-20

		10,881				(h)		11,159				5.6	%		May-20

		9,535				(i)		9,921				5.3	%		Jun-20

		41,441				(j)		42,462				5.83	%		Jul-20

		8,346				(k)		8,649				5.81	%		Feb-21

		6,100				(l)		6,233				6.01	%		Aug-21

		35,222				(m)		35,981				5.62	%		Jun-22

		10,718				(n)		10,930				6.08	%		Sep-22

		11,587				(o)		11,795				6.43	%		Apr-23

		14,909				(p)		15,598				6.28	%		Feb-24

		16,750				(q)		17,123				7.35	%		Jun-24

		14,535				(r)		14,849				7.6	%		Jun-24

		25,639				(s)		26,153				7.02	%		Jul-24

		30,429				(t)		31,093				7.45	%		Jul-24

		30,253				(u)		30,894				7.3	%		Jan-25

	15,735				(v)		16,087				6.18	%		Jan-26

	115,291				(w)		118,128				5.31	%		Apr-26

	35,125				(x)		36,075				4.3	%		Oct-26

	39,932				(y)		40,974				4.53	%		Nov-26

	18,645				(z)		19,118				4.7	%		Dec-26

	69,397				(aa)		70,856				5.84	%		May-27

	17,281				(bb)		17,718				4.04	%		Apr-28

	33,140				(cc)		34,391				3.51	%		Jun-28

	17,462				(dd)		17,895				3.99	%		Sep-28

	5,391				(ee)		—				4.88	%		Sep-32

	11,119				(ff)		—				8	%		Apr-34

Total fixed rate	784,757						789,872				5.7	%		9.3 Years

Variable rate loans:
	43,000				(gg)		—				LIBOR + 1.45	%		Jun-18

	14,525				(hh)		14,802				LIBOR + 1.65	%		Feb-16

	15,106				(ii)		15,394				LIBOR + 1.65	%		Feb-16

Total variable rate	$	72,631					$	30,196			LIBOR + 1.53	%		2.5 Years

Total notes payable	$	857,388					$	820,068			5.36	%		8.7 Years



*	Interest rate and scheduled maturity data presented as of December 31, 2014. Totals computed using weighted averages.


(a)	The loan is collateralized by Shops at Fairfax and Boulevard shopping centers and requires equal monthly principal and interest payments totaling $156,000 based upon a weighted average 23-year amortization schedule and a final payment of $15.2 million is due at loan maturity. Principal of $729,000 was amortized during 2014.

(b)	The loan is collateralized by Washington Square and requires equal monthly principal and interest payments of $264,000 based upon a 27.5-year amortization schedule and a final payment of $28.0 million at loan maturity. Principal of $1.2 million was amortized during 2014.

(c)	The loan is collateralized by three shopping centers, Broadlands Village, The Glen and Kentlands Square I, and requires equal monthly principal and interest payments of $306,000 based upon a 25-year amortization schedule and a final payment of $28.4 million at loan maturity. Principal of $1.5 million was amortized during 2014.

(d)	The loan is collateralized by Olde Forte Village and requires equal monthly principal and interest payments of $98,000 based upon a 25-year amortization schedule and a final payment of $9.0 million at loan maturity. Principal of $495,000 was amortized during 2014.

(e)	The loan is collateralized by Countryside and requires equal monthly principal and interest payments of $133,000 based upon a 25-year amortization schedule and a final payment of $12.3 million at loan maturity. Principal of $682,000 was amortized during 2014.

(f)	The loan is collateralized by Briggs Chaney MarketPlace and requires equal monthly principal and interest payments of $133,000 based upon a 25-year amortization schedule and a final payment of $12.2 million at loan maturity. Principal of $658,000 was amortized during 2014.

(g)	The loan is collateralized by Shops at Monocacy and requires equal monthly principal and interest payments of $112,000 based upon a 25-year amortization schedule and a final payment of $10.6 million at loan maturity. Principal of $596,000 was amortized during 2014.

(h)	The loan is collateralized by Boca Valley Plaza and requires equal monthly principal and interest payments of $75,000 based upon a 30-year amortization schedule and a final payment of $9.1 million at loan maturity. Principal of $278,000 was amortized during 2014.

(i)	The loan is collateralized by Palm Springs Center and requires equal monthly principal and interest payments of $75,000 based upon a 25-year amortization schedule and a final payment of $7.1 million at loan maturity. Principal of $386,000 was amortized during 2014.

(j)	The loan and a corresponding interest-rate swap closed on June 29, 2010 and are collateralized by Thruway. On a combined basis, the loan and the interest-rate swap require equal monthly principal and interest payments of $289,000 based upon a 25-year amortization schedule and a final payment of $34.8 million at loan maturity. Principal of $1,021,000 was amortized during 2014.

(k)	The loan is collateralized by Jamestown Place and requires equal monthly principal and interest payments of $66,000 based upon a 25-year amortization schedule and a final payment of $6.1 million at loan maturity. Principal of $303,000 was amortized during 2014.

(l)	The loan is collateralized by Hunt Club Corners and requires equal monthly principal and interest payments of $42,000 based upon a 30-year amortization schedule and a final payment of $5.0 million, at loan maturity. Principal of $133,000 was amortized during 2014.

(m)	The loan is collateralized by Lansdowne Town Center and requires monthly principal and interest payments of $230,000 based on a 30-year amortization schedule and a final payment of $28.2 million at loan maturity. Principal of $759,000 was amortized during 2014.

(n)	The loan is collateralized by Orchard Park and requires equal monthly principal and interest payments of $73,000 based upon a 30-year amortization schedule and a final payment of $8.6 million at loan maturity. Principal of $212,000 was amortized during 2014.

(o)	The loan is collateralized by BJ’s Wholesale and requires equal monthly principal and interest payments of $80,000 based upon a 30-year amortization schedule and a final payment of $9.3 million at loan maturity. Principal of $208,000 was amortized during 2014.

(p)	The loan is collateralized by Great Falls shopping center. The loan consists of three notes which require equal monthly principal and interest payments of $138,000 based upon a weighted average 26-year amortization schedule and a final payment of $6.3 million at maturity. Principal of $689,000 was amortized during 2014.

(q)	The loan is collateralized by Leesburg Pike and requires equal monthly principal and interest payments of $135,000 based upon a 25-year amortization schedule and a final payment of $11.5 million at loan maturity. Principal of $373,000 was amortized during 2014.

(r)	The loan is collateralized by Village Center and requires equal monthly principal and interest payments of $119,000 based upon a 25-year amortization schedule and a final payment of $10.1 million at loan maturity. Principal of $314,000 was amortized during 2014.

(s)	The loan is collateralized by White Oak and requires equal monthly principal and interest payments of $193,000 based upon a 24.4 year weighted amortization schedule and a final payment of $18.5 million at loan maturity. The loan was previously collateralized by Van Ness Square. During 2012, the Company substituted White Oak as the collateral and borrowed an additional $10.5 million. Principal of $514,000 was amortized during 2014.

(t)	The loan is collateralized by Avenel Business Park and requires equal monthly principal and interest payments of $246,000 based upon a 25-year amortization schedule and a final payment of $20.9 million at loan maturity. Principal of $664,000 was amortized during 2014.

(u)	The loan is collateralized by Ashburn Village and requires equal monthly principal and interest payments of $240,000 based upon a 25-year amortization schedule and a final payment of $20.5 million at loan maturity. Principal of $641,000 was amortized during 2014.

(v)	The loan is collateralized by Ravenwood and requires equal monthly principal and interest payments of $111,000 based upon a 25-year amortization schedule and a final payment of $10.1 million at loan maturity. Principal of $352,000 was amortized during 2014.

(w)	The loan is collateralized by Clarendon Center and requires equal monthly principal and interest payments of $753,000 based upon a 25-year amortization schedule and a final payment of $70.5 million at loan maturity. Principal of $2.8 million was amortized during 2014.

(x)	The loan is collateralized by Severna Park MarketPlace and requires equal monthly principal and interest payments of $207,000 based upon a 25-year amortization schedule and a final payment of $20.3 million at loan maturity. Principal of $950,000 was amortized during 2014.

(y)	The loan is collateralized by Kentlands Square II and requires equal monthly principal and interest payments of $240,000 based upon a 25-year amortization schedule and a final payment of $23.1 million at loan maturity. Principal of $1,042,000 was amortized during 2014.

(z)	The loan is collateralized by Cranberry Square and requires equal monthly principal and interest payments of $113,000 based upon a 25-year amortization schedule and a final payment of $10.9 million at loan maturity. Principal of $473,000 was amortized during 2014.

(aa)	The loan in the original amount of $73.0 million closed in May 2012, is collateralized by Seven Corners and requires equal monthly principal and interest payments of $463,200 based upon a 25-year amortization schedule and a final payment of $42.3 million at loan maturity. Principal of $1.5 million was amortized during 2014.

(bb)	The loan is collateralized by Hampshire Langley and requires equal monthly principal and interest payments of $95,400 based upon a 25 -year amortization schedule and a final payment of $9.5 million at loan maturity. Principal of $437,000 was amortized in 2014.

(cc)	The loan is collateralized by Beacon Center and requires equal monthly principal and interest payments of $203,200 based upon a 20-year amortization schedule and a final payment of $11.4 million at loan maturity. Principal of $1,251,000 was amortized in 2014.

(dd)	The loan is collateralized by Seabreeze Plaza and requires equal monthly principal and interest payments of $94,900 based upon a 25-year amortization schedule and a final payment of $9.5 million at loan maturity. Principal of $433,000 was amortized in 2014.

(ee)	The loan is a $71.6 million construction-to-permanent facility that is collateralized by and will finance a portion of the construction costs of Park Van Ness. During the construction period, interest will be funded by the loan. After conversion to a permanent loan, monthly principal and interest payments totaling $413,500 will be required based upon a 25-year amortization schedule. A final payment of $39.6 million will be due at maturity.

(ff)	The Company entered into a sale-leaseback transaction with its Olney property and is accounting for that transaction as a secured financing. The arrangement requires monthly payments of $60,400 which increase by 1.5% on May 1, 2015, and every May 1 thereafter. The arrangement provides for a final payment of $14.7 million and has an implicit interest rate of 8.0%. Negative amortization in 2014 totaled $119,000.

(gg)	The loan is a $275.0 million unsecured revolving credit facility. Interest accrues at a rate equal to the sum of one-month LIBOR plus a spread of 145 basis points. The line may be extended at the Company’s option for one year with payment of a fee of 0.15%. Monthly payments, if required, are interest only and vary depending upon the amount outstanding and the applicable interest rate for any given month.

(hh)	The loan is collateralized by Northrock and requires monthly principal and interest payments of approximately $47,000 and a final payment of $14.2 million at maturity. Principal of $277,000 was amortized during 2014.

(ii)	The loan is collateralized by Metro Pike Center and requires monthly principal and interest payments of approximately $48,000 and a final payment of $14.8 million at loan maturity. Principal of $288,000 was amortized during 2014.
The carrying value of the properties collateralizing the mortgage notes payable totaled $895.5 million and $907.2 million, as of December 31, 2014 and 2013, respectively. The Company’s credit facility requires the Company and its subsidiaries to maintain certain financial covenants, which are summarized below. The Company was in compliance as of December 31, 2014.

•	maintain tangible net worth, as defined in the loan agreement, of at least $542.1 million plus 80% of the Company’s net equity proceeds received after March 2014;

•	limit the amount of debt as a percentage of gross asset value, as defined in the loan agreement, to less than 60% (leverage ratio);

•	limit the amount of debt so that interest coverage will exceed 2.0 x on a trailing four-quarter basis (interest expense coverage); and

•	limit the amount of debt so that interest, scheduled principal amortization and preferred dividend coverage exceeds 1.3x on a trailing four-quarter basis (fixed charge coverage).
Mortgage notes payable at each of December 31, 2014 and 2013, totaling $51.0 million, are guaranteed by members of the Saul Organization. As of December 31, 2014, the scheduled maturities of all debt including scheduled principal amortization for years ended December 31 are as follows:


(in thousands)	Balloon				Scheduled				Total
	Payments				Principal
					Amortization
2015	$	14,885			$	23,192			$	38,077

2016	28,879				23,496				52,375

2017	—				24,679				24,679

2018	70,748			(a)	24,822				95,570

2019	60,794				23,489				84,283

Thereafter	426,652				135,752				562,404

	$	601,958			$	255,430			$	857,388

(a) Includes $43.0 million outstanding under the line of credit.
The components of interest expense are set forth below.


(in thousands)	Year ended December 31,
	2014				2013				2012
Interest incurred	$	45,396			$	45,502			$	48,010

Amortization of deferred debt costs	1,327				1,257				1,576

Capitalized interest	(689		)		(170		)		(42		)
Total	$	46,034			$	46,589			$	49,544

Deferred debt costs capitalized during the years ending December 31, 2014, 2013 and 2012 totaled $1.3 million, $3.2 million and $2.2 million, respectively.

Lease_Agreements

Lease Agreements	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Lease Agreements	LEASE AGREEMENTS
	Lease income includes primarily base rent arising from noncancelable leases. Base rent (including straight-line rent) for the years ended December 31, 2014, 2013, and 2012, amounted to $164.6 million, $159.9 million, and $152.8 million, respectively. Future contractual payments under noncancelable leases for years ended December 31 (which exclude the effect of straight-line rents), are as follows:


	(in thousands)
	2015	$	152,661

	2016	135,703

	2017	116,025

	2018	96,439

	2019	73,626

	Thereafter	275,551

		$	850,005

	The majority of the leases provide for rental increases and expense recoveries based on fixed annual increases or increases in the Consumer Price Index and increases in operating expenses. The expense recoveries generally are payable in equal installments throughout the year based on estimates, with adjustments made in the succeeding year. Expense recoveries for the years ended December 31, 2014, 2013, and 2012, amounted to $32.1 million, $30.9 million, and $30.4 million, respectively. In addition, certain retail leases provide for percentage rent based on sales in excess of the minimum specified in the tenant’s lease. Percentage rent amounted to $1.5 million, $1.6 million, and $1.5 million, for the years ended December 31, 2014, 2013, and 2012, respectively.

LongTerm_Lease_Obligations

Long-Term Lease Obligations	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Long-Term Lease Obligations	LONG-TERM LEASE OBLIGATIONS
	Certain properties are subject to noncancelable long-term leases which apply to land underlying the Shopping Centers. Certain of the leases provide for periodic adjustments of the base annual rent and require the payment of real estate taxes on the underlying land. The leases will expire between 2058 and 2068. Reflected in the accompanying consolidated financial statements is minimum ground rent expense of $176,000, $176,000, and $176,000, for the years ended December 31, 2014, 2013, and 2012, respectively. The future minimum rental commitments under these ground leases are as follows:



		Year ending December 31,
	(In thousands)	2015		2016		2017		2018		2019		Thereafter		Total
	Beacon Center	$	60	$	60	$	60	$	60	$	60	$	2,541	$	2,841

	Olney	56		56		56		56		57		3,760		4,041

	Southdale	60		60		60		60		60		2,885		3,185

	Total	$	176	$	176	$	176	$	176	$	177	$	9,186	$	10,067


	In addition to the above, Flagship Center consists of two developed out parcels that are part of a larger adjacent community shopping center formerly owned by the Saul Organization and sold to an affiliate of a tenant in 1991. The Company has a 90-year ground leasehold interest which commenced in September 1991 with a minimum rent of one dollar per year. Countryside shopping center was acquired in February 2004. Because of certain land use considerations, approximately 3.4% of the underlying land is held under a 99-year ground lease. The lease requires the Company to pay minimum rent of one dollar per year as well as its pro-rata share of the real estate taxes.
	The Company’s corporate headquarters space is leased by a member of the Saul Organization. The lease commenced in March 2002 was extended in 2012 for five years, 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 Company and the Saul Organization entered into a Shared Services Agreement whereby each party pays 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 the years ended December 31, 2014, 2013, and 2012 was $840,800, $850,600, and $850,000, respectively. Expenses arising from the lease are included in general and administrative expense (see Note 9 – Related Party Transactions).

Stockholders_Equity_and_Noncon

Stockholders' Equity and Noncontrolling Interest	12 Months Ended
Stockholders' Equity and Noncontrolling Interest	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Stockholders' Equity and Noncontrolling Interest	STOCKHOLDERS’ EQUITY AND NONCONTROLLING INTEREST
	The Consolidated Statements of Operations for the years ended December 31, 2014, 2013, and 2012 reflect noncontrolling interest of $11.0 million, $4.0 million, and $6.4 million, respectively, representing the Saul Organization’s share of the net income for the year.
	In November 2003, the Company sold 4,000,000 depositary shares, each representing 1/100th of a share of 8% Series A Cumulative Redeemable Preferred Stock (the "Series A Stock"). The depositary shares are redeemable, in whole or in part at the Company’s option, from time to time, at $25.00 per share. The depositary shares pay an annual dividend of $2.00 per share, equivalent to 8% of the $25.00 per share liquidation preference. The Series A preferred stock has no stated maturity, is not subject to any sinking fund or mandatory redemption and is not convertible into any other securities of the Company. Investors in the depositary shares generally have no voting rights, but will have limited voting rights if the Company fails to pay dividends for six or more quarters (whether or not declared or consecutive) and in certain other events. In March 2013, the Company redeemed 60% of its then-outstanding Series A Stock. In December 2014, the Company redeemed the remaining outstanding Series A Stock. Costs associated with the redemptions were charged against accumulated deficit in the respective periods.
	In March 2008, the Company sold 3,173,115 depositary shares, each representing 1/100th of a share of 9% Series B Cumulative Redeemable Preferred Stock (the "Series B Stock"). The depositary shares may be redeemed at the Company’s option, on or after March 15, 2013, in whole or in part, at $25.00 per share. The depositary shares pay an annual dividend of $2.25 per share, equivalent to 9% of the $25.00 per share liquidation preference. The Series B preferred stock has no stated maturity, is not subject to any sinking fund or mandatory redemption and is not convertible into any other securities of the Company. Investors in the depositary shares generally have no voting rights, but will have limited voting rights if the Company fails to pay dividends for six or more quarters (whether or not declared or consecutive) and in certain other events. In March 2013, the Company redeemed all of its Series B Stock. Costs associated with the redemption were charged against accumulated deficit.
	On February 12, 2013, the Company sold, in an underwritten public offering, 5.6 million depositary shares, each representing 1/100th of a share of 6.875% Series C Cumulative Redeemable Preferred Stock ("Series C Stock"), and received net cash proceeds of approximately $135.2 million. The depositary shares may be redeemed on or after February 12, 2018 at the Company’s option, in whole or in part, at the $25.00 liquidation preference plus accrued but unpaid dividends. The depositary shares pay an annual dividend of $1.71875 per share, equivalent to 6.875% of the $25.00 liquidation preference. The first dividend was paid on April 15, 2013 and covered the period from February 12, 2013 through March 31, 2013. The Series C Stock has no stated maturity, is not subject to any sinking fund or mandatory redemption and is not convertible into any other securities of the Company except in connection with certain changes of control or delisting events. Investors in the depositary shares generally have no voting rights, but will have limited voting rights if the Company fails to pay dividends for six or more quarters (whether or not declared or consecutive) and in certain other events. On November 12, 2014, the Company sold, in an underwritten public offering, 1.6 million depositary shares of Series C Stock and received net cash proceeds of approximately $39.3 million (the "Additional Series C Stock"). The terms of Additional Series C Stock are identical to the Series C Stock.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS
	The Chairman and Chief Executive Officer, the President and Chief Operating Officer, 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 $379,000, $369,000, and $379,000, for 2014, 2013, and 2012, respectively. All amounts deferred by employees and contributed by 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 years ended December 31, 2014, 2013, and 2012, the Company contributed three times the amount deferred by employees. The Company’s expense, included in general and administrative expense, totaled $192,800, $191,300, and $238,000, for the years ended December 31, 2014, 2013, and 2012, respectively. All amounts deferred by employees and the Company are fully vested. The cumulative unfunded liability under this plan was $1.8 million and $1.6 million, at December 31, 2014 and 2013, 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. Senior management has determined that the final allocations of shared costs are reasonable. The terms of the Agreement and the payments made thereunder 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 years ended December 31, 2014, 2013, and 2012, which included rental expense for the Company’s headquarters lease (see Note 7. Long Term Lease Obligations), totaled $7.4 million, $6.3 million, and $6.0 million, respectively. The amounts are expensed when incurred and are primarily reported as general and administrative expenses or capitalized to specific development projects in these consolidated financial statements. As of December 31, 2014 and 2013, accounts payable, accrued expenses and other liabilities included $543,000 and $499,000, respectively, representing billings 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 with the B. F. Saul Real Estate Investment Trust, a member of the Saul Organization (the “Predevelopment Agreement”). The Predevelopment Agreement, which expires on December 31, 2015, and which may be extended to December 31, 2016, 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 billed by the third-parties on a pro rata basis based on the acreage owned by each entity and neither party is obligated to advance funds to the other.
	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 counter-signature fees in connection with the Company’s insurance program. Such commissions and fees amounted to approximately $427,300, $447,300, and $372,000, for the years ended December 31, 2014, 2013, and 2012, respectively.
	Effective as of September 4, 2012, the Company entered into a consulting agreement with B. F. Saul III, one of the Company’s former presidents, whereby Mr. Saul III provided certain consulting services to the Company as an independent contractor and was paid at a rate of $60,000 per month. The consulting agreement included certain noncompete, nonsolicitation and nondisclosure covenants, and expired in September 2014. During 2014, 2013 and 2012 such consulting fees totaled $495,000, $720,000 and $225,000, respectively.

Stock_Option_Plan

Stock Option Plan	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Plan	STOCK OPTION PLAN
	The Company established a stock option plan in 1993 (the “1993 Plan”) for the purpose of attracting and retaining executive officers and other key personnel. The 1993 Plan provides for grants of options to purchase up to 400,000 shares of common stock. The 1993 Plan authorizes the Compensation Committee of the Board of Directors to grant options at an exercise price which may not be less than the market value of the common stock on the date the option is granted.
	At the annual meeting of the Company’s stockholders in 2004, the stockholders approved the adoption of the 2004 stock plan for the purpose of attracting and retaining executive officers, directors and other key personnel. The 2004 stock plan was subsequently amended by the Company’s stockholders at the 2008 Annual Meeting and further amended at the 2013 Annual Meeting (the “Amended 2004 Plan”). The Amended 2004 Plan, which terminates in 2023, provides for grants of options to purchase up to 2,000,000 shares of common stock as well as grants of up to 200,000 shares of common stock to directors. The Amended 2004 Plan authorizes the Compensation Committee of the Board of Directors to grant options at an exercise price which may not be less than the market value of the common stock on the date the option is granted.
	Effective May 6, 2005, the Compensation Committee granted options to purchase 162,500 shares (35,500 incentive stock options and 127,000 nonqualified stock options) to twelve Company officers and to twelve Company directors (the “2005 Options”), which expire on May 5, 2015. The officers’ 2005 Options vested 25% per year over four years and are subject to early expiration upon termination of employment. The directors’ options were immediately exercisable. The exercise price of $33.22 per share was the closing market price of the Company’s common stock on the date of the award. Using the Black-Scholes model, the Company determined the total fair value of the 2005 Options to be $484,500, of which $413,400 and $71,100 were the values assigned to the officer options and director options, respectively. Because the directors’ options vested immediately, the entire $71,100 was expensed as of the date of grant. The expense of the officers’ options was recognized as compensation expense monthly during the four years the options vested.
	Effective May 1, 2006, the Compensation Committee granted options to purchase 30,000 shares (all nonqualified stock options) to twelve Company directors (the “2006 Options”), which were immediately exercisable and expire on April 30, 2016. The exercise price of $40.35 per share was the closing market price of the Company’s common stock on the date of the award. Using the Black-Scholes model, the Company determined the total fair value of the 2006 Options to be $143,400. Because the directors’ options vested immediately, the entire $143,400 was expensed as of the date of grant. No options were granted to the Company’s officers in 2006.
	Effective April 27, 2007, the Compensation Committee granted options to purchase 165,000 shares (27,560 incentive stock options and 137,440 nonqualified stock options) to thirteen Company officers and twelve Company Directors (the “2007 options”), which expire on April 26, 2017. The officers’ 2007 Options vest 25% per year over four years and are subject to early expiration upon termination of employment. The directors’ options were immediately exercisable. The exercise price of $54.17 per share was the closing market price of the Company’s common stock on the date of award. Using the Black-Scholes model, the Company determined the total fair value of the 2007 Options to be $1.5 million, of which $1.3 million and $285,300 were the values assigned to the officer options and director options, respectively. Because the directors’ options vested immediately, the entire $285,300 was expensed as of the date of grant. The expense for the officers’ options was recognized as compensation expense monthly during the four years the options vested.
	Effective April 25, 2008, the Compensation Committee granted options to purchase 30,000 shares (all nonqualified stock options) to twelve Company directors (the “2008 Options”), which were immediately exercisable and expire on April 24, 2018. The exercise price of $50.15 per share was the closing market price of the Company’s common stock on the date of the award. Using the Black-Scholes model, the Company determined the total fair value of the 2008 Options to be $254,700. Because the directors’ options vest immediately, the entire $254,700 was expensed as of the date of grant. No options were granted to the Company’s officers in 2008.
	Effective April 24, 2009, the Compensation Committee granted options to purchase 32,500 shares (all nonqualified stock options) to thirteen Company directors (the “2009 Options”), which were immediately exercisable and expire on April 23, 2019. The exercise price of $32.68 per share was the closing market price of the Company’s common stock on the date of the award. Using the Black-Scholes model, the Company determined the total fair value of the 2009 Options to be $222,950. Because the directors’ options vested immediately, the entire $222,950 was expensed as of the date of grant. No options were granted to the Company’s officers in 2009.
	Effective May 7, 2010, the Compensation Committee granted options to purchase 32,500 shares (all nonqualified stock options) to thirteen Company directors (the “2010 Options”), which were immediately exercisable and expire on May 6, 2020. The exercise price of $38.76 per share was the closing market price of the Company’s common stock on the date of the award. Using the Black-Scholes model, the Company determined the total fair value of the 2010 Options to be $287,950. Because the directors’ options vested immediately, the entire $287,950 was expensed as of the date of grant. No options were granted to the Company’s officers in 2010.
	Effective May 13, 2011, the Compensation Committee granted options to purchase 195,000 shares (65,300 incentive stock options and 129,700 nonqualified stock options) to fifteen Company officers and thirteen Company Directors (the “2011 options”), which expire on May 12, 2021. The officers’ 2011 Options vest 25% per year over four years and are subject to early expiration upon termination of employment. The directors’ 2011 options were immediately exercisable. The exercise price of $41.82 per share was the closing market price of the Company’s common stock on the date of award. Using the Black-Scholes model, the Company determined the total fair value of the 2011 Options to be $1.6 million, of which $1.3 million and $297,375 were assigned to the officer options and director options, respectively. Because the directors’ options vested immediately, the entire $297,375 was expensed as of the date of grant. The expense for the officers’ options is being recognized as compensation expense monthly during the four years the options vest.
	Effective May 4, 2012, the Compensation Committee granted options to purchase 277,500 shares (26,157 incentive stock options and 251,343 nonqualified stock options) to fifteen Company officers and fourteen Company Directors (the “2012 options”), which expire on May 3, 2022. The officers’ 2012 Options vest 25% per year over four years and are subject to early expiration upon termination of employment. The directors’ 2012 Options were immediately exercisable. The exercise price of $39.29 per share was the closing market price of the Company’s common stock on the date of award. Using the Black-Scholes model, the Company determined the total fair value of the 2012 Options to be $1.7 million, of which $1.4 million and $257,250 were assigned to the officer options and director options, respectively. Because the directors’ options vested immediately, the entire $257,250 was expensed as of the date of grant. The expense for the officers’ options is being recognized as compensation expense monthly during the four years the options vest.
	Effective May 10, 2013, the Compensation Committee granted options to purchase 237,500 shares (35,592 incentive stock options and 201,908 nonqualified stock options) to fifteen Company officers and fourteen Company Directors (the "2013 options"), which expire on May 9, 2023. The officers' 2013 Options vest 25% per year over four years and are subject to early expiration upon termination of employment. The directors' 2013 options were immediately exercisable. The exercise price of $44.42 per share was the closing market price of the Company's common stock on the date of award. Using the Black-Scholes model, the Company determined the total fair value of the 2013 Options to be $1.5 million, of which $1.3 million and $0.3 million were assigned to the officer options and director options, respectively. Because the directors' options vested immediately, the entire $0.3 million was expensed as of the date of grant. The expense for the officers' options is being recognized as compensation expense monthly during the four years the option was vested.
	Effective May 9, 2014, the Compensation Committee granted options to purchase 200,000 shares (29,300 incentive stock options and 170,700 nonqualified stock options) to eighteen Company officers and twelve Company Directors (the “2014 options”), which expire on May 8, 2024. The officers’ 2014 Options vest 25% per year over four years and are subject to early expiration upon termination of employment. The directors’ 2014 Options were immediately exercisable. The exercise price of $47.03 per share was the closing market price of the Company’s common stock on the date of award. Using the Black-Scholes model, the Company determined the total fair value of the 2014 Options to be $1.3 million, of which $1.2 million and $109,500 were assigned to the officer options and director options, respectively. Because the directors’ options vested immediately, the entire $109,500 was expensed as of the date of grant. The expense for the officers’ options is being recognized as compensation expense monthly during the four years the options vest.
	The following table summarizes the amount and activity of each grant, the total value and variables used in the computation and the amount expensed and included in general and administrative expense in the Consolidated Statements of Operations for the years ended December 31, 2014, 2013 and 2012:


	SAUL CENTERS, INC.
	Notes to Consolidated Financial Statements
	Stock options issued

		Directors
	Grant date	5/6/05				5/1/06				4/27/07				4/25/08				4/24/09				5/7/10				5/13/11			5/4/12			5/10/13			5/9/14				Subtotals
	Total grant	30,000				30,000				30,000				30,000				32,500				32,500				32,500			35,000			35,000			30,000				317,500

	Vested	30,000				30,000				30,000				30,000				32,500				32,500				32,500			35,000			35,000			30,000				317,500

	Exercised	22,500				10,000				—				—				20,000				10,000				10,000			10,000			7,500			—				90,000

	Forfeited	—				2,500				7,500				7,500				—				2,500				2,500			—			—			—				22,500

	Exercisable at December 31, 2014	7,500				17,500				22,500				22,500				12,500				20,000				20,000			25,000			27,500			30,000				205,000

	Remaining unexercised	7,500				17,500				22,500				22,500				12,500				20,000				20,000			25,000			27,500			30,000				205,000

	Exercise price	$	33.22			$	40.35			$	54.17			$	50.15			$	32.68			$	38.76			$	41.82		$	39.29		$	44.42		$	47.03

	Volatility	0.198				0.206				0.225				0.237				0.344				0.369				0.358			0.348			0.333			0.173

	Expected life (years)	10				9				8				7				6				5				5			5			5			5

	Assumed yield	6.91		%		5.93		%		4.39		%		4.09		%		4.54		%		4.23		%		4.16		%	4.61		%	4.53		%	4.48		%
	Risk-free rate	4.28		%		5.11		%		4.65		%		3.49		%		2.19		%		2.17		%		1.86		%	0.78		%	0.82		%	1.63		%
	Total value at grant date	$	71,100			$	143,400			$	285,300			$	254,700			$	222,950			$	287,950			$	297,375		$	257,250		$	278,250		$	109,500			$	2,207,775

	Expensed in previous years	71,100				143,400				285,300				254,700				222,950				287,950				297,375			—			—			—				1,562,775

	Expensed in 2012	—				—				—				—				—				—				—			257,250			—			—				257,250

	Expensed in 2013	—				—				—				—				—				—				—			—			278,250			—				278,250

	Expensed in 2014	—				—				—				—				—				—				—			—			—			109,500				109,500

	Future expense	—				—				—				—				—				—				—			—			—			—				—

		Officers

	Grant date	5/6/05				4/27/07				5/13/11				5/4/12				5/10/13				5/9/14				Subtotals													Grand Totals
	Total grant	132,500				135,000				162,500				242,500				202,500				170,000				1,045,000													1,362,500

	Vested	118,750				67,500				105,625				56,250				50,625				—				398,750													716,250

	Exercised	115,750				3,528				46,889				30,000				15,625				—				211,792													301,792

	Forfeited	13,750				67,500				43,750				135,000				30,000				—				290,000													312,500

Exercisable at December 31, 2014	3,000				63,972				47,486				26,250				35,000				—				175,708													380,708

Remaining unexercised	3,000				63,972				71,861				77,500				156,875				170,000				543,208													748,208

Exercise price	$	33.22			$	54.17			$	41.82			$	39.29			$	44.42			$	47.03

Volatility	0.207				0.233				0.33				0.315				0.304				0.306

Expected life (years)	8				6.5				8				8				8				7

Assumed yield	6.37		%		4.13		%		4.81		%		5.28		%		5.12		%		4.89		%
Risk-free rate	4.15		%		4.61		%		2.75		%		1.49		%		1.49		%		2.17		%
Gross value at grant date	$	413,400			$	1,339,200			$	1,366,625			$	1,518,050			$	1,401,300			$	1,349,800			$	7,388,375												$	9,596,150

Estimated forfeitures	35,100				62,000				387,550				889,690				280,468				168,749				1,823,557													1,823,557

Expensed in previous years	378,300				1,277,200				186,347				—				—				—				1,841,847													3,404,622

Expensed in 2012					—				270,391				104,724				—				—				375,115													632,365

Expensed in 2013					—				235,350				157,083				209,027				—				601,460													879,710

Expensed in 2014	—				—				217,475				157,092				283,910				196,848				855,325													964,825

Future expense	—				—				69,512				209,461				627,895				984,203				1,891,071													1,891,071

Weighted average term of remaining future expense					2.7			years

The table below summarizes the option activity for the years 2014, 2013, and 2012:


	2014							2013							2012
	Shares			Weighted				Shares			Weighted				Shares			Weighted
				Average							Average							Average
				Exercise							Exercise							Exercise
				Price							Price							Price
Outstanding at January 1	753,625			$	42.55			570,840			$	41.04			674,585			$	40.4

Granted	200,000			47.03				237,500			44.42				277,500			39.29

Exercised	(167,917	)		37.71				(49,715	)		33.15				(149,995	)		31.03

Expired/Forfeited	(37,500	)		43.56				(5,000	)		52.16				(231,250	)		43.56

Outstanding December 31	748,208			44.79				753,625			42.55				570,840			41.04

Exercisable at December 31	380,708			44.85				413,000			42.42				377,715			41.41


The intrinsic value of options exercised in 2014, 2013, and 2012, was $2.0 million, $0.6 million and $1.6 million, respectively. The intrinsic value of options outstanding and exercisable at year end 2014 was $9.3 million and $4.7 million, respectively. The intrinsic value measures the difference between the options’ exercise price and the closing share price quoted by the New York Stock Exchange as of the date of measurement. The date of exercise was the measurement date for shares exercised during the period. At December 31, 2014, the final trading day of calendar 2014, the closing price of $57.19 per share was used for the calculation of aggregate intrinsic value of options outstanding and exercisable at that date. At December 31, 2014, there were no options with an exercise price in excess of the market closing price. The weighted average remaining contractual life of the Company’s exercisable and outstanding options at December 31, 2014 are 5.4 and 7.0 years, respectively.

NonOperating_Items

Non-Operating Items	12 Months Ended
Non-Operating Items	Dec. 31, 2014
Other Income and Expenses [Abstract]
Non-Operating Items	NON-OPERATING ITEMS
Non-Operating Items	Gain on casualty settlement in 2013 and 2012 reflect insurance proceeds received in excess of the carrying value of assets damaged during a hail storm at French Market in 2012. The insurance proceeds funded substantially all of the restoration of the damaged property.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS
	The carrying values of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses are reasonable estimates of their fair value. The aggregate fair value of the notes payable with fixed-rate payment terms was determined using Level 3 data in a discounted cash flow approach, which is based upon management’s estimate of borrowing rates and loan terms currently available to the Company for fixed rate financing, and assuming long term interest rates of approximately 3.65% and 4.85%, would be approximately $886.4 million and $828.7 million as of December 31, 2014 and 2013, respectively, compared to the carrying value of $784.8 million and $789.9 million at December 31, 2014 and 2013, respectively. A change in any of the significant inputs may lead to a change in the Company’s fair value measurement of its debt.
	Effective June 30, 2011, the Company determined that one of its interest-rate swap arrangements was a highly effective hedge of the cash flows under one of its variable-rate mortgage loans and designated the swap as a cash flow hedge of that mortgage. The swap is carried at fair value with changes in fair value recognized either in income or comprehensive income depending on the effectiveness of the swap. The following chart summarizes the changes in fair value of the Company’s swaps for the indicated periods.



	(Dollars in thousands)	Year ended December 31,
		2014			2013			2012
	Increase (decrease) in fair value:
	Recognized in earnings	$	(10	)	$	(7	)	$	36

	Recognized in other comprehensive income	(675		)	2,897			(932		)

	Total	$	(685	)	$	2,890		$	(896	)

	The Company carries its interest rate swaps at fair value. The Company has determined the majority of the inputs used to value its derivative fall within Level 2 of the fair value hierarchy with the exception of the impact of counter-party risk, which was determined using Level 3 inputs and are not significant. Derivative instruments are classified within Level 2 of the fair value hierarchy because their values are determined using third-party pricing models which contain inputs that are derived from observable market data. Where possible, the values produced by the pricing models are verified by the market prices. Valuation models require a variety of inputs, including contractual terms, market prices, yield curves, credit spreads, measure of volatility, and correlations of such inputs. The swap agreement terminates on July 1, 2020. As of December 31, 2014, the fair value of the interest-rate swap was approximately $3.2 million and is included in “Accounts payable, accrued expenses and other liabilities” in the consolidated balance sheets. The decrease in value from inception of the swap designated as a cash flow hedge is reflected in “Other Comprehensive Income” in the Consolidated Statements of Comprehensive Income.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
Commitments and Contingencies	Neither the Company nor the Current Portfolio Properties are subject to any material litigation, nor, to management’s knowledge, is any material litigation currently threatened against the Company, other than routine litigation and administrative proceedings arising in the ordinary course of business. Management believes that these items, individually or in the aggregate, will not have a material adverse impact on the Company or the Current Portfolio Properties.

Distributions

Distributions	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Distributions	DISTRIBUTIONS
	In December 1995, the Company established a Dividend Reinvestment and Stock Purchase Plan (the “Plan”), to allow its stockholders and holders of limited partnership interests an opportunity to buy additional shares of common stock by reinvesting all or a portion of their dividends or distributions. The Plan provides for investing in newly issued shares of common stock at a 3% discount from market price without payment of any brokerage commissions, service charges or other expenses. All expenses of the Plan are paid by the Company. The Operating Partnership also maintains a similar dividend reinvestment plan that mirrors the Plan, which allows holders of limited partnership interests the opportunity to buy either additional limited partnership units or common stock shares of the Company.
	The Company paid common stock distributions of $1.56 per share in 2014 and $1.44 per share during each of 2013 and 2012, Series A preferred stock dividends of $2.41 per share in 2014 and $2.00 per depositary share during each of 2013 and 2012, Series B preferred stock dividends of $0.99 and $2.25 per share during 2013 and 2012, respectively, and Series C preferred stock dividends of $1.72 and $1.09 per depository share during 2014 and 2013, respectively. Of the common stock dividends paid, $1.56 per share, $0.96 per share, and $0.95 per share, represented ordinary dividend income in 2014, 2013, and 2012, respectively and $0.48 per share and $0.49 per share, represented return of capital to the shareholders in 2013 and 2012, respectively. All of the preferred stock dividends paid were considered ordinary dividend income.
	The following summarizes distributions paid during the years ended December 31, 2014, 2013, and 2012, and includes activity in the Plan as well as limited partnership units issued from the reinvestment of unit distributions:


		Total Distributions to						Dividend Reinvestments
	(Dollars in thousands, except per share amounts)	Preferred		Common		Limited		Common	Discounted		Limited Partnership Units Issued	Average Unit Price
		Stockholders		Stockholders		Partnership		Stock Shares	Share Price
						Unitholders		Issued
	Distributions during 2014
	October 31	$	3,856	$	8,348	$	2,879	40,142	$	52.71

	July 31	3,206		8,314		2,879		57,696	46.79

	April 30	3,206		8,269		2,838		60,212	44.14		104,831	$	44.77

	January 31	3,206		7,415		2,521		39,588	45.15		91,352	45.8

	Total 2014	$	13,474	$	32,346	$	11,117	197,638			196,183

	Distributions during 2013

	October 31	$	3,206	$	7,388	$	2,489	48,836	$	46.27	88,309	$	46.93

	July 31	3,206		7,327		2,489		138,019	45.21

	April 30	4,364		7,272		2,489		142,839	42.85

	January 31	3,785		7,218		2,489		145,468	41.67

	Total 2013	$	14,561	$	29,205	$	9,956	475,162			88,309

	Distributions during 2012

	October 31	$	3,785	$	7,120	$	2,489	141,960	42.23

	July 31	3,785		7,063		2,489		144,881	40.43

	April 30	3,785		7,005		2,489		145,118	38.93

	January 31	3,785		6,947		2,489		163,429	34.44

	Total 2012	$	15,140	$	28,135	$	9,956	595,388

	In December 2014, the Board of Directors of the Company authorized a distribution of $0.40 per common share payable in January 2015, to holders of record on January 16, 2015. As a result, $8.4 million was paid to common shareholders on January 30, 2015. Also, $2.9 million was paid to limited partnership unitholders on January 30, 2015 ($0.40 per Operating Partnership unit). The Board of Directors authorized preferred stock dividends of $0.4297 per Series C depositary share to holders of record on January 7, 2015. As a result, $3.1 million was paid to preferred shareholders on January 15, 2015. These amounts are reflected as a reduction of stockholders’ equity in the case of common stock and preferred stock dividends and noncontrolling interests deductions in the case of limited partner distributions and are included in dividends and distributions payable in the accompanying consolidated financial statements.

Interim_Results_Unaudited

Interim Results (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Interim Results (Unaudited)	INTERIM RESULTS (Unaudited)
	The following summary presents the results of operations of the Company for the quarterly periods of calendar years 2014 and 2013.


	(In thousands, except per share amounts)	2014
		1st Quarter			2nd Quarter		3rd Quarter		4th Quarter
	Revenue	$	52,947		$	52,286	$	50,595	$	51,264

	Operating income before loss on early extinguishment of debt, gain on casualty settlement, and noncontrolling interests	12,713			14,423		12,479		12,314

	Gain on sales of properties	—			6,069		—		—

	Net income attributable to Saul Centers, Inc.	10,287			16,054		10,106		10,496

	Net income available to common shareholders	7,081			12,847		6,900		5,274

	Net income available to common shareholders per diluted share	0.34			0.62		0.33		0.25





	(In thousands, except per share amounts)	2013
		1st Quarter			2nd Quarter		3rd Quarter		4th Quarter
	Revenue	$	49,186		$	48,809	$	49,756	$	50,146

	Operating income before loss on early extinguishment of debt, gain on casualty settlement, and noncontrolling interests	3,388			7,711		11,959		12,211

	Net income attributable to Saul Centers, Inc.	4,984			6,594		9,398		9,896

	Net income (loss) available to common shareholders.	(4,608		)	3,387		6,192		6,690

	Net income (loss) available to common shareholders per diluted share	(0.23		)	0.17		0.3		0.33

Business_Segments

Business Segments	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Business Segments	BUSINESS SEGMENTS
	The Company has two reportable business segments: Shopping Centers and Mixed-Use Properties. The accounting policies of the segments are the same as those described in the summary of significant accounting policies (see Note 2). The Company evaluates performance based upon income and cash flows from real estate for the combined properties in each segment. All of our properties within each segment generate similar types of revenues and expenses related to tenant rent, reimbursements and operating expenses. Although services are provided to a range of tenants, the types of services provided to them are similar within each segment. The properties in each portfolio have similar economic characteristics and the nature of the products and services provided to our tenants and the method to distribute such services are consistent throughout the portfolio. Certain reclassifications have been made to prior year information to conform to the 2014 presentation.


	SAUL CENTERS, INC.
	Notes to Consolidated Financial Statements
	(In thousands)	Shopping				Mixed-Use				Corporate				Consolidated
	As of or for the year ended December 31, 2014	Centers				Properties				and Other				Totals
	Real estate rental operations:
	Revenue	$	154,385			$	52,632			$	75			$	207,092

	Expenses	(33,781		)		(15,732		)		—				(49,513		)

	Income from real estate	120,604				36,900				75				157,579

	Interest expense and amortization of deferred debt costs	—				—				(46,034		)		(46,034		)

	General and administrative	—				—				(16,961		)		(16,961		)

	Subtotal	120,604				36,900				(62,920		)		94,584

	Depreciation and amortization of deferred leasing costs	(28,082		)		(13,121		)		—				(41,203		)

	Acquisition related costs	(949		)		—				—				(949		)

	Predevelopment expenses	—				(503		)		—				(503		)

	Change in fair value of derivatives	—				—				(10		)		(10		)

	Gain on sale of property	6,069				—				—				6,069

	Net income (loss)	$	97,642			$	23,276			$	(62,930	)		$	57,988

	Capital investment	$	66,508			$	23,760			$	—			$	90,268

	Total assets	$	946,819			$	307,901			$	12,267			$	1,266,987


	As of or for the year ended December 31, 2013
	Real estate rental operations:
	Revenue	$	145,219			$	52,609			$	69			$	197,897

	Expenses	(30,729		)		(17,213		)		—				(47,942		)

	Income from real estate	114,490				35,396				69				149,955

	Interest expense and amortization of deferred debt costs	—				—				(46,589		)		(46,589		)

	General and administrative	—				—				(14,951		)		(14,951		)

	Subtotal	114,490				35,396				(61,471		)		88,415

	Depreciation and amortization of deferred leasing costs	(27,340		)		(21,790		)		—				(49,130		)

	Acquisition related costs	(106		)		—				—				(106		)

	Predevelopment expenses	—				(3,910		)		—				(3,910		)

	Change in fair value of derivatives	—				—				(7		)		(7		)

	Loss on early extinguishment of debt	—				—				(497		)		(497		)

	Gain on casualty settlement	77				—				—				77

Net income (loss)	$	87,121			$	9,696			$	(61,975	)		$	34,842

Capital investment	$	18,232			$	8,207			$	—			$	26,439

Total assets	$	888,109			$	293,512			$	17,054			$	1,198,675




SAUL CENTERS, INC.
Notes to Consolidated Financial Statements (continued)
(In thousands)	Shopping				Mixed-Use				Corporate				Consolidated
As of or for the year ended December 31, 2012	Centers				Properties				and Other				Totals
Real estate rental operations:
Revenue	$	137,647			$	52,309			$	136			$	190,092

Expenses	(30,139		)		(17,131		)		—				(47,270		)

Income from real estate	107,508				35,178				136				142,822

Interest expense and amortization of deferred debt costs	—				—				(49,544		)		(49,544		)

General and administrative	—				—				(14,274		)		(14,274		)

Subtotal	107,508				35,178				(63,682		)		79,004

Depreciation and amortization of deferred leasing costs	(25,667		)		(14,445		)		—				(40,112		)

Acquisition related costs	(1,129		)		—				—				(1,129		)

Predevelopment expenses	—				(2,667		)		—				(2,667		)

Change in fair value of derivatives	—				—				36				36

Gain on casualty settlement	219				—				—				219

Gains on sales of properties	4,510				—				—				4,510

Loss from operations of property sold	(81		)		—				—				(81		)

Net income (loss)	$	85,360			$	18,066			$	(63,646	)		$	39,780

Capital investment	$	46,353			$	8,290			$	—			$	54,643

Total assets	$	894,027			$	301,355			$	11,927			$	1,207,309

Subsequent_Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events

	The Company has reviewed operating activities for the period subsequent to December 31, 2014 and prior to the date that financial settlements are issued, March 6, 2015, and determined there are no subsequent events that are required to be disclosed.

Real_Estate_and_Accumulated_De

Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2014
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Real Estate and Accumulated Depreciation

	SAUL CENTERS, INC.
	Real Estate and Accumulated Depreciation
	December 31, 2014
	(Dollars in Thousands)
					Costs																												Buildings
					Capitalized			Basis at Close of Period																									and
		Initial			Subsequent			Land			Buildings			Leasehold			Total			Accumulated			Book			Related			Date of		Date		Improvements
		Basis			to						and			Interests						Depreciation			Value			Debt			Construction		Acquired		Depreciable
					Acquisition						Improvements																						Lives in Years
	Shopping Centers
	Ashburn Village, Ashburn, VA	$	11,431		$	19,492		$	6,764		$	24,159		$	—		$	30,923		$	10,868		$	20,055		$	30,253		1994 & 2000-6		Mar-94		40

	Ashland Square Phase I, Dumfries, VA	1,178			7,503			1,178			7,503			—			8,681			776			7,905			—			2007, 2013		4-Dec		20 & 50

	Beacon Center, Alexandria, VA	1,493			18,232			—			18,631			1,094			19,725			12,707			7,018			33,140			1960 & 1974		Jan-72		40 & 50

	BJ’s Wholesale Club, Alexandria, VA	22,623			—			22,623			—			—			22,623			—			22,623			11,587					8-Mar		—

	Boca Valley Plaza, Boca Raton, FL	16,720			1,297			5,735			12,282			—			18,017			3,478			14,539			10,881					4-Feb		40

	Boulevard, Fairfax, VA	4,883			4,487			3,687			5,683			—			9,370			2,194			7,176			9,239			1969, 1999 & 2009		Apr-94		40

	Briggs Chaney MarketPlace, Silver Spring, MD	27,037			2,957			9,789			20,205			—			29,994			6,076			23,918			15,761					4-Apr		40

	Broadlands Village, Ashburn, VA	5,316			25,285			5,300			25,301			—			30,601			8,354			22,247			18,826			2002-3, 2004 & 2006		2-Mar		40 & 50

	Countryside Marketplace, Sterling, VA	28,912			3,039			7,666			24,285			—			31,951			6,538			25,413			15,819					4-Feb		40

	Cranberry Square, Westminster, MD	31,578			464			6,700			25,342			—			32,042			2,061			29,981			18,645					11-Sep		40

	Cruse MarketPlace, Cumming, GA	12,226			198			3,920			8,504			—			12,424			2,350			10,074			—					4-Mar		40

	Flagship Center, Rockville, MD	160			9			169			—			—			169			—			169			—			1972		Jan-72		—

	French Market, Oklahoma City, OK	5,781			13,782			1,118			18,445			—			19,563			9,444			10,119			—			1972 & 1998		Mar-74		50

	Germantown, Germantown, MD	3,576			743			2,034			2,285			—			4,319			1,385			2,934			—			1990		Aug-93		40

	750/730 N. Glebe Road, Arlington, VA	42,313			13			40,907			1,419			—			42,326			160			42,166			—					08/14, 12/14		3 & 2

	The Glen, Woodbridge, VA	12,918			7,536			5,299			15,155			—			20,454			7,327			13,127			9,045			1993 & 2005		Jun-94		40

	Great Eastern, District Heights, MD	4,993			10,669			3,785			11,877			—			15,662			7,726			7,936			—			1958 & 1960		Jan-72		40

	Great Falls Center, Great Falls, VA	41,750			2,350			14,766			29,334			—			44,100			4,988			39,112			14,909					8-Mar		40

	Hampshire Langley, Takoma, MD	3,159			3,338			1,856			4,641			—			6,497			3,351			3,146			17,281			1960		Jan-72		40

	Hunt Club Corners, Apopka, FL	12,584			3,115			4,822			10,877			—			15,699			2,555			13,144			6,100					6/06, 12/12		40

	Jamestown Place, Altamonte Springs, FL	14,055			960			4,455			10,560			—			15,015			2,532			12,483			8,346					5-Nov		40

	Kentlands Square I, Gaithersburg, MD	14,379			177			5,006			9,550			—			14,556			2,958			11,598			7,527			2002		2-Sep		40

	Kentlands Square II, Gaithersburg, MD	76,723			954			22,800			54,877			—			77,677			4,387			73,290			39,932					9/11, 9/13		40

	Kentlands Place, Gaithersburg, MD	1,425			7,163			1,425			7,163			—			8,588			2,863			5,725			—			2005		4-Jan		50

	Lansdowne Town Center, Leesburg, VA	6,545			36,313			6,546			36,312			—			42,858			10,174			32,684			35,222			2006		2-Nov		50

	Leesburg Pike Plaza, Baileys Crossroads, VA	2,418			6,173			1,132			7,459			—			8,591			5,582			3,009			16,750			1965		Feb-66		40

Lumberton Plaza, Lumberton, NJ	4,400			11,160			950			14,610			—			15,560			11,676			3,884			—			1975		Dec-75		40

Metro Pike Center, Rockville, MD	33,123			2,069			26,064			9,128			—			35,192			771			34,421			15,106					10-Dec		40

Shops at Monocacy, Frederick, MD	9,541			14,002			9,260			14,283			—			23,543			4,320			19,223			14,014			2003-4		3-Nov		50

Northrock, Warrenton, VA	12,686			14,981			12,686			14,981			—			27,667			2,283			25,384			14,525			2009		8-Jan		50

Olde Forte Village, Ft. Washington, MD	15,933			6,499			5,409			17,023			—			22,432			5,583			16,849			11,454			2003-4		3-Jul		40

Olney, Olney, MD	1,884			1,672			—			3,556			—			3,556			3,180			376			11,119			1972		Nov-75		40

Orchard Park, Dunwoody, GA	19,377			781			7,751			12,407			—			20,158			2,343			17,815			10,718					7-Jul		40

Palm Springs Center, Altamonte Springs, FL	18,365			659			5,739			13,285			—			19,024			3,247			15,777			9,535					5-Mar		40

Ravenwood, Baltimore, MD	1,245			4,097			703			4,639			—			5,342			2,602			2,740			15,735			1959 & 2006		Jan-72		40

11503 Rockville Pike/5541 Nicholson Lane, Rockville, MD	14,861			11,700			22,113			4,448			—			26,561			473			26,088			—					10-Oct		40
																														12-Dec
1500/1580/1582/1584 Rockville Pike, Rockville, MD	51,156			568			43,863			7,861			—			51,724			1,962			49,762			—					12/12, 1/14, 4/14, 12/14		5, 10, 5, 4

Seabreeze Plaza, Palm Harbor, FL	24,526			1,391			8,665			17,252			—			25,917			4,056			21,861			17,462					5-Nov		40

Market Place at Sea Colony, Bethany Beach, DE	2,920			81			1,147			1,854			—			3,001			320			2,681			—					8-Mar		40

Seven Corners, Falls Church, VA	4,848			43,692			4,913			43,627			—			48,540			25,486			23,054			69,397			1956 & 1997		Jul-73		40

Severna Park Marketplace, Severna Park, MD	63,254			63			12,700			50,617			—			63,317			4,112			59,205			35,125					11-Sep		40

Shops at Fairfax, Fairfax, VA	2,708			9,898			992			11,614			—			12,606			6,914			5,692			6,160			1975 & 1999		Jun-75		50

Smallwood Village Center, Waldorf, MD	17,819			7,618			6,402			19,035			—			25,437			5,025			20,412			—					6-Jan		40

Southdale, Glen Burnie, MD	3,650			20,919			—			23,947			622			24,569			20,467			4,102			—			1962 & 1986		Jan-72		40

Southside Plaza, Richmond, VA	6,728			9,597			1,878			14,447			—			16,325			11,100			5,225			—			1958		Jan-72		40

South Dekalb Plaza, Atlanta, GA	2,474			3,899			703			5,670			—			6,373			4,285			2,088			—			1970		Feb-76		40

Thruway, Winston-Salem, NC	4,778			23,157			5,496			22,334			105			27,935			13,715			14,220			41,441			1955 & 1965		May-72		40

Village Center, Centreville, VA	16,502			1,870			7,851			10,521			—			18,372			5,713			12,659			14,535			1990		Aug-93		40

Westview Village, Frederick, MD	5,146			22,292			5,153			22,285			—			27,438			4,245			23,193			—			2009		7-Nov		50

White Oak, Silver Spring, MD	6,277			5,311			4,649			6,939			—			11,588			5,604			5,984			25,639			1958 & 1967		Jan-72		40

Other Buildings / Improvements				115						115						115			84			31			—

Total Shopping Centers	750,377			394,340			384,569			758,327			1,821			1,144,717			270,400			874,317			631,228


Mixed-Use Properties
Avenel Business Park, Gaithersburg, MD	21,459			27,945			3,756			45,648			—			49,404			31,663			17,741			30,429			1984, 1986, 1990, 1998 & 2000		12/2/84		35 & 40

Clarendon Center, Arlington, VA (1)	12,753			185,485			16,287			181,951			—			198,238			21,709			176,529			115,291			2010		7/73, 1/96 & 4/02

Crosstown Business Center, Tulsa, OK	3,454			6,358			604			9,208			—			9,812			6,792			3,020			—			1974		Oct-75		40

601 Pennsylvania Ave., Washington, DC	5,479			62,169			5,667			61,981			—			67,648			46,500			21,148			—			1986		Jul-73		35

Washington Square, Alexandria, VA	2,034			51,926			544			53,416			—			53,960			19,553			34,407			32,049			1952 & 2000		Jul-73		50

Total Mixed-Use Properties	45,179			333,883			26,858			352,204			—			379,062			126,217			252,845			177,769


Development Land
Ashland Square Phase II, Manassas, VA	5,292			1,717			7,009			—			—			7,009			—			7,009			—					4-Dec

New Market, New Market, MD	2,088			286			2,374			—			—			2,374			—			2,374			—					5-Sep

Park Van Ness, Washington, DC	2,242			—			2,242			24,755			—			26,997			—			26,997			5,391					07/73 and 02/11

Total Development Land	9,622			2,003			11,625			24,755			—			36,380			—			36,380			5,391

Total	$	805,178		$	730,226		$	423,052		$	1,135,286		$	1,821		$	1,560,159		$	396,617		$	1,163,542		$	814,388



-1	Includes the North and South Blocks and Residential
Depreciation and amortization related to the real estate investments reflected in the statements of operations is calculated over the estimated useful lives of the assets as follows:


Base building		Generally 35 - 50 years or a shorter period if management determines that
		the building has a shorter useful life.
Building components		Up to 20 years
Tenant improvements		The shorter of the term of the lease or the useful life
		of the improvements
The aggregate remaining net basis of the real estate investments for federal income tax purposes was approximately $1.2 billion at December 31, 2014. Depreciation and amortization are provided on the declining balance and straight-line methods over the estimated useful lives of the assets.
The changes in total real estate investments and related accumulated depreciation for each of the years in the three year period ended December 31, 2014 are summarized as follows:



(In thousands)	2014			2013			2012
Total real estate investments:
Balance, beginning of year	$	1,459,439		$	1,466,068		$	1,417,845

Acquisitions	70,921			5,124			34,247

Improvements	34,417			21,991			23,095

Retirements	(4,618		)	(33,744		)	(9,119		)
Balance, end of year	$	1,560,159		$	1,459,439		$	1,466,068

Total accumulated depreciation:
Balance, beginning of year	$	364,663		$	353,305		$	326,397

Depreciation expense	35,933			43,204			34,565

Retirements	(3,979		)	(31,846		)	(7,657		)
Balance, end of year	$	396,617		$	364,663		$	353,305

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2014
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations
Nature of Operations	The Company, which conducts all of its activities through its subsidiaries, the Operating Partnership and Subsidiary Partnerships, engages in the ownership, operation, management, leasing, acquisition, renovation, expansion, development and financing of community and neighborhood shopping centers and mixed-used properties, primarily in the Washington, DC/Baltimore metropolitan area. Because the properties are located primarily in the Washington, DC/Baltimore metropolitan area, a disproportionate economic downturn in the local economy would have a greater negative impact on our overall financial performance than on the overall financial performance of a company with a portfolio that is more geographically diverse. A majority of the Shopping Centers are anchored by several major tenants.
Principles of Consolidation	Principles of Consolidation
Principles of Consolidation	The accompanying consolidated financial statements include the accounts of Saul Centers, its subsidiaries, and the Operating Partnership and Subsidiary Partnerships which are majority owned by Saul Centers. All significant intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates
Use of Estimates	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Real Estate Investment Properties	Real Estate Investment Properties
	The Company purchases real estate investment properties from time to time and records assets acquired and liabilities assumed, including land, buildings, and intangibles related to in-place leases and customer relationships, based on their fair values. The fair value of buildings generally is determined as if the buildings were vacant upon acquisition and then subsequently leased at market rental rates and considers the present value of all cash flows expected to be generated by the property including an initial lease up period. From time to time the Company may purchase a property for future development purposes. The property may be improved with an existing structure that would be demolished as part of the development. In such cases, the fair value of the building may be determined based only on existing leases and not include estimated cash flows related to future leases. In certain circumstances, such as if the building is vacant and the Company intends to demolish the building in the near term, the entire purchase price will be allocated to land.
	The Company determines the fair value of above and below market intangibles associated with in-place leases by assessing the net effective rent and remaining term of the lease relative to market terms for similar leases at acquisition taking into consideration the remaining contractual lease period, renewal periods, and the likelihood of the tenant exercising its renewal options. The fair value of a below market lease component is recorded as deferred income and accreted as additional lease revenue over the remaining contractual lease period. If the fair value of the below market lease intangible includes fair value associated with a renewal option, such amounts are not accreted until the renewal option is exercised. If the renewal option is not exercised the value is recognized at that time. The fair value of above market lease intangibles is recorded as a deferred asset and is amortized as a reduction of lease revenue over the remaining contractual lease term. The Company determines the fair value of at-market in-place leases considering the cost of acquiring similar leases, the foregone rents associated with the lease-up period and carrying costs associated with the lease-up period. Intangible assets associated with at-market in-place leases are amortized as additional expense over the remaining contractual lease term. To the extent customer relationship intangibles are present in an acquisition, the fair values of the intangibles are amortized over the lives of the customer relationships. The Company has never recorded a customer relationship intangible asset. Acquisition-related transaction costs are either (a) expensed as incurred when related to business combinations or (b) capitalized to land and/or building when related to asset acquisitions.
	If there is an event or change in circumstance that indicates a potential impairment in the value of a real estate investment property, the Company prepares an analysis to determine whether the carrying value of the real estate investment property exceeds its estimated fair value. The Company considers both quantitative and qualitative factors including recurring operating losses, significant decreases in occupancy, and significant adverse changes in legal factors and business climate. If impairment indicators are present, the Company compares the projected cash flows of the property over its remaining useful life, on an undiscounted basis, to the carrying value of that property. The Company assesses its undiscounted projected cash flows based upon estimated capitalization rates, historic operating results and market conditions that may affect the property. If the carrying value is greater than the undiscounted projected cash flows, the Company would recognize an impairment loss equivalent to an amount required to adjust the carrying amount to its then estimated fair value. The fair value of any property is sensitive to the actual results of any of the aforementioned estimated factors, either individually or taken as a whole. Should the actual results differ from management’s projections, the valuation could be negatively or positively affected. The Company did not recognize an impairment loss on any of its real estate in 2014, 2013, or 2012.
	Interest, real estate taxes, development related salary costs and other carrying costs are capitalized on projects under development and construction. Once construction is substantially completed and the assets are placed in service, their rental income, real estate tax expense, property operating expenses (consisting of payroll, repairs and maintenance, utilities, insurance and other property related expenses) and depreciation are included in current operations. Property operating expenses are charged to operations as incurred. Interest expense capitalized totaled $688,900, $170,000, and $42,300 during 2014, 2013, and 2012, respectively. Commercial development projects are considered substantially complete and available for occupancy upon completion of tenant improvements, but no later than one year from the cessation of major construction activity. Multi-family residential development projects are considered substantially complete and available for occupancy upon receipt of the certificate of occupancy from the appropriate licensing authority. Substantially completed portions of a project are accounted for as separate projects.
	Depreciation is calculated using the straight-line method and estimated useful lives of generally between 35 and 50 years for base buildings, or a shorter period if management determines that the building has a shorter useful life, and up to 20 years for certain other improvements that extend the useful lives. Leasehold improvements expenditures are capitalized when certain criteria are met, including when the Company supervises construction and will own the improvements. Tenant improvements are amortized, over the shorter of the lives of the related leases or the useful life of the improvement, using the straight-line method.
Deferred Leasing Costs	Deferred Leasing Costs
Deferred Leasing Costs	Deferred leasing costs consist of commissions paid to third-party leasing agents, internal direct costs such as employee compensation and payroll-related fringe benefits directly related to time spent performing leasing-related activities for successful commercial leases and amounts attributed to in place leases associated with acquired properties and are amortized, using the straight-line method, over the term of the lease or the remaining term of an acquired lease. Leasing related activities include evaluating the prospective tenant’s financial condition, evaluating and recording guarantees, collateral and other security arrangements, negotiating lease terms, preparing lease documents and closing the transaction. Unamortized deferred costs are charged to expense if the applicable lease is terminated prior to expiration of the initial lease term.
Construction in Progress	Construction in Progress
Construction in Progress	Construction in progress includes preconstruction and development costs of active projects. Preconstruction costs include legal, zoning and permitting costs and other project carrying costs incurred prior to the commencement of construction. Development costs include direct construction costs and indirect costs incurred subsequent to the start of construction such as architectural, engineering, construction management and carrying costs consisting of interest, real estate taxes and insurance.
Accounts Receivable and Accrued Income	Accounts Receivable and Accrued Income
Accounts Receivable and Accrued Income	Accounts receivable primarily represent amounts currently due from tenants in accordance with the terms of the respective leases. Receivables are reviewed monthly and reserves are established with a charge to current period operations when, in the opinion of management, collection of the receivable is doubtful.
Cash and Cash Equivalents	Cash and Cash Equivalents
Cash and Cash Equivalents	Cash and cash equivalents include short-term investments. Short-term investments include money market accounts and other investments which generally mature within three months, measured from the acquisition date, and/or are readily convertible to cash. Substantially all of the Company’s cash balances at December 31, 2014 are held in non-interest bearing accounts at various banks. From time to time the Company may maintain deposits with financial institutions in amounts in excess of federally insured limits. The Company has not experienced any losses on such deposits and believes it is not exposed to any significant credit risk on those deposits.
Deferred Debt Costs	Deferred Debt Costs
Deferred Debt Costs	Deferred debt costs consist of fees and costs incurred to obtain long-term financing, construction financing and the revolving line of credit. These fees and costs are being amortized on a straight-line basis over the terms of the respective loans or agreements, which approximates the effective interest method.
Deferred Income	Deferred Income
Deferred Income	Deferred income consists of payments received from tenants prior to the time they are earned and recognized by the Company as revenue, including tenant prepayment of rent for future periods, real estate taxes when the taxing jurisdiction has a fiscal year differing from the calendar year reimbursements specified in the lease agreement and tenant construction work provided by the Company. In addition, deferred income includes the fair value of certain below market leases.
Derivative Financial Instruments	Derivative Financial Instruments
Derivative Financial Instruments	The Company may, when appropriate, employ derivative instruments, such as interest-rate swaps, to mitigate the risk of interest rate fluctuations. The Company does not enter into derivative or other financial instruments for trading or speculative purposes. Derivative financial instruments are carried at fair value as either assets or liabilities on the consolidated balance sheets. For those derivative instruments that qualify, the Company may designate the hedging instrument, based upon the exposure being hedged, as a fair value hedge or a cash flow hedge. Derivative instruments that are designated as a hedge are evaluated to ensure they continue to qualify for hedge accounting. The effective portion of any gain or loss on the hedge instruments is reported as a component of accumulated other comprehensive income (loss) and recognized in earnings within the same line item associated with the forecasted transaction in the same period or periods during which the hedged transaction affects earnings. Any ineffective portion of the change in fair value of a derivative instrument is immediately recognized in earnings. For derivative instruments that do not meet the criteria for hedge accounting, or that qualify and are not designated, changes in fair value are immediately recognized in earnings.
Discontinued Operations	Discontinued Operations
Discontinued Operations	During 2012, the Company sold its West Park and Belvedere properties for $2.0 million and $4.0 million and recognized gains of $1.1 million and $3.4 million, respectively. The results of operations of West Park and Belvedere for the year ended December 31, 2012 are included in the statements of operations as “Loss from operations of properties sold.”
Revenue Recognition	Revenue Recognition
Revenue Recognition	Rental and interest income are accrued as earned except when doubt exists as to collectability, in which case the accrual is discontinued. Recognition of rental income commences when control of the space has been given to the tenant. When rental payments due under leases vary from a straight-line basis because of free rent periods or stepped increases, income is recognized on a straight-line basis. Expense recoveries represent a portion of property operating expenses billed to the tenants, including common area maintenance, real estate taxes and other recoverable costs. Expense recoveries are recognized in the period in which the expenses are incurred. Rental income based on a tenant’s revenue (“percentage rent”) is accrued when a tenant reports sales that exceed a specified breakpoint, pursuant to the terms of their respective leases.
Income Taxes	Income Taxes
	The Company made an election to be treated, and intends to continue operating so as to qualify, as a REIT under the Code, commencing with its taxable year ended December 31, 1993. A REIT generally will not be subject to federal income taxation, provided that distributions to its stockholders equal or exceed its REIT taxable income and complies with certain other requirements. Therefore, no provision has been made for federal income taxes in the accompanying consolidated financial statements.
	As of December 31, 2014, the Company had no material unrecognized tax benefits and there exist no potentially significant unrecognized tax benefits which are reasonably expected to occur within the next twelve months. The Company recognizes penalties and interest accrued related to unrecognized tax benefits, if any, as general and administrative expense.
Stock Based Employee Compensation, Deferred Compensation and Stock Plan for Directors	Stock Based Employee Compensation, Deferred Compensation and Stock Plan for Directors
	The Company uses the fair value method to value and account for employee stock options. The fair value of options granted is determined at the time of each award using the Black-Scholes model, a widely used method for valuing stock based employee compensation, and the following assumptions: (1) Expected Volatility determined using the most recent trading history of the Company’s common stock (month-end closing prices) corresponding to the average expected term of the options; (2) Average Expected Term of the options is based on prior exercise history, scheduled vesting and the expiration date; (3) Expected Dividend Yield determined by management after considering the Company’s current and historic dividend yield rates, the Company’s yield in relation to other retail REITs and the Company’s market yield at the grant date; and (4) a Risk-free Interest Rate based upon the market yields of US Treasury obligations with maturities corresponding to the average expected term of the options at the grant date. The Company amortizes the value of options granted ratably over the vesting period and includes the amounts as compensation in general and administrative expenses.
	The Company has a stock plan, which was originally approved in 2004, amended in 2008 and 2013 and which expires in 2023, for the purpose of attracting and retaining executive officers, directors and other key personnel (the "Stock Plan"). Pursuant to the Stock Plan, the Compensation Committee established a Deferred Compensation Plan for Directors for the benefit of its directors and their beneficiaries, which replaced a previous Deferred Compensation and Stock Plan for Directors. A director may make an annual election to defer all or part of his or her director’s fees and has the option to have the fees paid in cash, in shares of common stock or in a combination of cash and shares of common stock upon separation from the Board. If the director elects to have fees paid in stock, fees earned during a calendar quarter are aggregated and divided by the common stock’s closing market price on the first trading day of the following quarter to determine the number of shares to be allocated to the director. As of December 31, 2014, the directors’ deferred fee accounts comprise 232,262 shares.
	The Compensation Committee has also approved an annual award of shares of the Company’s common stock as additional compensation to each director serving on the Board of Directors as of the record date for the Annual Meeting of Stockholders. The shares are awarded as of each Annual Meeting of Shareholders, and their issuance may not be deferred.
Noncontrolling Interest	Noncontrolling Interest
Noncontrolling Interest	Saul Centers is the sole general partner of the Operating Partnership, owning a 74.2% common interest as of December 31, 2014. Noncontrolling interest in the Operating Partnership is comprised of limited partnership units owned by the Saul Organization. Noncontrolling interest reflected on the accompanying consolidated balance sheets is increased for earnings allocated to limited partnership interests and distributions reinvested in additional units, and is decreased for limited partner distributions. Noncontrolling interest reflected on the consolidated statements of operations represents earnings allocated to limited partnership interests held by the Saul Organization.
Per Share Data	Per Share Data
Per Share Data	Per share data for net income (basic and diluted) is computed using weighted average shares of common stock. Convertible limited partnership units and employee stock options are the Company’s potentially dilutive securities. For all periods presented, the convertible limited partnership units are anti-dilutive. For the years ended December 31, 2014, 2013, and 2012, options totaling 106,875, 112,500, and 117,500, respectively, are not dilutive because the average share price of the Company’s common stock was less than the exercise prices. The treasury stock method was used to measure the effect of the dilution.
Legal Contingencies	Legal Contingencies
Legal Contingencies	The Company is subject to various legal proceedings and claims that arise in the ordinary course of business, which are generally covered by insurance. Upon determination that a loss is probable to occur and can be reasonably estimated, the estimated amount of the loss is recorded in the financial statements.
Recently Issued Accounting Standards	Recently Issued Accounting Standards
	In April 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-08, “Presentation of Financial Statements (Topic 205) and Property Plant and Equipment (Topic 360)” (“ASU 2014-08”). ASU 2014-08 changes the requirements for reporting discontinued operations such that disposals of components of an entity will be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations. ASU 2014-08 also requires additional disclosures about discontinued operations. ASU 2014-08 is effective for annual periods beginning after December 15, 2014, and interim periods within those years and early adoption is permitted. The Company retrospectively adopted ASU 2014-08 on April 15, 2014. The adoption of ASU 2014-08 did not have a material impact on the Company’s financial condition or results of operations.
	In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”). ASU 2014-09 will replace most existing revenue recognition guidance and will require an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. ASU 2014-09 is effective for annual periods beginning after December 15, 2016, and interim periods within those years and early adoption is not permitted. ASU 2014-09 must be applied retrospectively by either restating prior periods or by recognizing the cumulative effect as of the first date of application. We have not yet selected a transition method and are evaluating the impact that ASU 2014-09 will have on our consolidated financial statements and related disclosures.
Reclassifications	Reclassifications
Reclassifications	Certain reclassifications have been made to prior years to conform to the presentation used for year ended December 31, 2014.

Organization_Formation_and_Bas1

Organization, Formation, and Basis of Presentation (Tables)	12 Months Ended
Organization, Formation, and Basis of Presentation (Tables)	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Properties Acquired and/or Developed	The following table lists the significant properties acquired, developed and/or disposed of by the Company since January 1, 2012.



	Name of Property	Location	Type	Year of
				Acquisition/
				Development/
				Disposal
	Acquisitions
	1500 Rockville Pike	Rockville, Maryland	Shopping Center	Dec-12
	5541 Nicholson Lane	Rockville, Maryland	Shopping Center	Dec-12
	1580 Rockville Pike	Rockville, Maryland	Shopping Center	Jan-14
	1582 Rockville Pike	Rockville, Maryland	Shopping Center	Apr-14
	750 N. Glebe Road	Arlington, Virginia	Shopping Center	Aug-14
	730 N. Glebe Road	Arlington, Virginia	Shopping Center	Dec-14
	1584 Rockville Pike	Rockville, Maryland	Shopping Center	Dec-14

	Developments
	Park Van Ness	Washington, DC	Mixed-Use	2013/2014

	Dispositions
	West Park	Oklahoma City, Oklahoma	Shopping Center	Jul-12
	Belvedere	Baltimore, Maryland	Shopping Center	Dec-12
	Giant Center	Milford Mill, Maryland	Shopping Center	Apr-14

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Construction in Progress	The following table shows the components of construction in progress.


			December 31,
	(in thousands)		2014			2013

	Park Van Ness		$	26,998		$	7,901

	Other		3,263			1,966

	Total		$	30,261		$	9,867


Allowance for Doubtful Accounts	Accounts receivable in the accompanying consolidated financial statements are shown net of an allowance for doubtful accounts of $0.7 million and $0.6 million, at December 31, 2014 and 2013, respectively.



	(In thousands)	Year ended December 31,
		2014			2013			2012
	Beginning Balance	$	572		$	1,208		$	671

	Provision for Credit Losses	680			968			1,160

	Charge-offs	(575		)	(1,604		)	(623		)
	Ending Balance	$	677		$	572		$	1,208

Basic and Diluted Shares Outstanding

		December 31,
	(Shares in thousands)	2014			2013			2012
	Weighted average common shares outstanding - Basic	20,772			20,364			19,649

	Effect of dilutive options	49			37			51

	Weighted average common shares outstanding - Diluted	20,821			20,401			19,700

	Average share price	$	49.09		$	45.44		$	40.94

Real_Estate_Acquired_Tables

Real Estate Acquired (Tables)	12 Months Ended
	Dec. 31, 2014
Real Estate [Abstract]
Allocation of Purchase Prices to Acquired Assets and Liabilities	The purchase prices were allocated to the assets acquired and liabilities assumed based on their fair value as shown in the following table.


	(in thousands)	1580			1582			750 N.		730 N.		1584			Total
		Rockville Pike			Rockville Pike			Glebe Road		Glebe Road		Rockville Pike
	Land	$	9,600		$	9,742		$	38,224	$	2,683	$	5,798		$	66,047

	Buildings	2,200			828			1,327		78		440			4,873

	In-place Leases	513			849			449		39		249			2,099

	Above Market Rent	—			—			—		—		—			—

	Below Market Rent	(4,313		)	(419		)	—		—		(337		)	(5,069		)

	Total Purchase Price	$	8,000		$	11,000		$	40,000	$	2,800	$	6,150		$	67,950


Amortization of Intangible Assets and Deferred Income Related to in Place Leases	As of December 31, 2014, scheduled amortization of intangible assets and deferred income related to in place leases is as follows:


	(In thousands)	Lease acquisition costs			Above market leases			Below market leases
	2015	$	1,252		$	2		$	1,787

	2016	988			1			1,722

	2017	796			1			1,701

	2018	737			1			1,617

	2019	550			—			1,473

	Thereafter	1,739			—			9,670

	Total	$	6,062		$	5		$	17,970

Mortgage_Notes_Payable_Revolvi1

Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Summary of Notes payable	The following is a summary of notes payable as of December 31, 2014 and 2013:



	Notes Payable	December 31,										Interest			Scheduled
	(Dollars in thousands)	2014						2013				Rate *			Maturity *
	Fixed rate mortgages:	$	15,399			(a)		$	16,128			7.45	%		Jun-15

		32,049				(b)		33,246				6.01	%		Feb-18

		35,398				(c)		36,937				5.88	%		Jan-19

		11,454				(d)		11,949				5.76	%		May-19

		15,819				(e)		16,501				5.62	%		Jul-19

		15,761				(f)		16,419				5.79	%		Sep-19

		14,014				(g)		14,610				5.22	%		Jan-20

		10,881				(h)		11,159				5.6	%		May-20

		9,535				(i)		9,921				5.3	%		Jun-20

		41,441				(j)		42,462				5.83	%		Jul-20

		8,346				(k)		8,649				5.81	%		Feb-21

		6,100				(l)		6,233				6.01	%		Aug-21

		35,222				(m)		35,981				5.62	%		Jun-22

		10,718				(n)		10,930				6.08	%		Sep-22

		11,587				(o)		11,795				6.43	%		Apr-23

		14,909				(p)		15,598				6.28	%		Feb-24

		16,750				(q)		17,123				7.35	%		Jun-24

		14,535				(r)		14,849				7.6	%		Jun-24

		25,639				(s)		26,153				7.02	%		Jul-24

		30,429				(t)		31,093				7.45	%		Jul-24

		30,253				(u)		30,894				7.3	%		Jan-25

		15,735				(v)		16,087				6.18	%		Jan-26

		115,291				(w)		118,128				5.31	%		Apr-26

		35,125				(x)		36,075				4.3	%		Oct-26

		39,932				(y)		40,974				4.53	%		Nov-26

		18,645				(z)		19,118				4.7	%		Dec-26

		69,397				(aa)		70,856				5.84	%		May-27

		17,281				(bb)		17,718				4.04	%		Apr-28

		33,140				(cc)		34,391				3.51	%		Jun-28

	17,462				(dd)		17,895				3.99	%		Sep-28

	5,391				(ee)		—				4.88	%		Sep-32

	11,119				(ff)		—				8	%		Apr-34

Total fixed rate	784,757						789,872				5.7	%		9.3 Years

Variable rate loans:
	43,000				(gg)		—				LIBOR + 1.45	%		Jun-18

	14,525				(hh)		14,802				LIBOR + 1.65	%		Feb-16

	15,106				(ii)		15,394				LIBOR + 1.65	%		Feb-16

Total variable rate	$	72,631					$	30,196			LIBOR + 1.53	%		2.5 Years

Total notes payable	$	857,388					$	820,068			5.36	%		8.7 Years



*	Interest rate and scheduled maturity data presented as of December 31, 2014. Totals computed using weighted averages.


(a)	The loan is collateralized by Shops at Fairfax and Boulevard shopping centers and requires equal monthly principal and interest payments totaling $156,000 based upon a weighted average 23-year amortization schedule and a final payment of $15.2 million is due at loan maturity. Principal of $729,000 was amortized during 2014.

(b)	The loan is collateralized by Washington Square and requires equal monthly principal and interest payments of $264,000 based upon a 27.5-year amortization schedule and a final payment of $28.0 million at loan maturity. Principal of $1.2 million was amortized during 2014.

(c)	The loan is collateralized by three shopping centers, Broadlands Village, The Glen and Kentlands Square I, and requires equal monthly principal and interest payments of $306,000 based upon a 25-year amortization schedule and a final payment of $28.4 million at loan maturity. Principal of $1.5 million was amortized during 2014.

(d)	The loan is collateralized by Olde Forte Village and requires equal monthly principal and interest payments of $98,000 based upon a 25-year amortization schedule and a final payment of $9.0 million at loan maturity. Principal of $495,000 was amortized during 2014.

(e)	The loan is collateralized by Countryside and requires equal monthly principal and interest payments of $133,000 based upon a 25-year amortization schedule and a final payment of $12.3 million at loan maturity. Principal of $682,000 was amortized during 2014.

(f)	The loan is collateralized by Briggs Chaney MarketPlace and requires equal monthly principal and interest payments of $133,000 based upon a 25-year amortization schedule and a final payment of $12.2 million at loan maturity. Principal of $658,000 was amortized during 2014.

(g)	The loan is collateralized by Shops at Monocacy and requires equal monthly principal and interest payments of $112,000 based upon a 25-year amortization schedule and a final payment of $10.6 million at loan maturity. Principal of $596,000 was amortized during 2014.

(h)	The loan is collateralized by Boca Valley Plaza and requires equal monthly principal and interest payments of $75,000 based upon a 30-year amortization schedule and a final payment of $9.1 million at loan maturity. Principal of $278,000 was amortized during 2014.

(i)	The loan is collateralized by Palm Springs Center and requires equal monthly principal and interest payments of $75,000 based upon a 25-year amortization schedule and a final payment of $7.1 million at loan maturity. Principal of $386,000 was amortized during 2014.

(j)	The loan and a corresponding interest-rate swap closed on June 29, 2010 and are collateralized by Thruway. On a combined basis, the loan and the interest-rate swap require equal monthly principal and interest payments of $289,000 based upon a 25-year amortization schedule and a final payment of $34.8 million at loan maturity. Principal of $1,021,000 was amortized during 2014.

(k)	The loan is collateralized by Jamestown Place and requires equal monthly principal and interest payments of $66,000 based upon a 25-year amortization schedule and a final payment of $6.1 million at loan maturity. Principal of $303,000 was amortized during 2014.

(l)	The loan is collateralized by Hunt Club Corners and requires equal monthly principal and interest payments of $42,000 based upon a 30-year amortization schedule and a final payment of $5.0 million, at loan maturity. Principal of $133,000 was amortized during 2014.

(m)	The loan is collateralized by Lansdowne Town Center and requires monthly principal and interest payments of $230,000 based on a 30-year amortization schedule and a final payment of $28.2 million at loan maturity. Principal of $759,000 was amortized during 2014.

(n)	The loan is collateralized by Orchard Park and requires equal monthly principal and interest payments of $73,000 based upon a 30-year amortization schedule and a final payment of $8.6 million at loan maturity. Principal of $212,000 was amortized during 2014.

(o)	The loan is collateralized by BJ’s Wholesale and requires equal monthly principal and interest payments of $80,000 based upon a 30-year amortization schedule and a final payment of $9.3 million at loan maturity. Principal of $208,000 was amortized during 2014.

(p)	The loan is collateralized by Great Falls shopping center. The loan consists of three notes which require equal monthly principal and interest payments of $138,000 based upon a weighted average 26-year amortization schedule and a final payment of $6.3 million at maturity. Principal of $689,000 was amortized during 2014.

(q)	The loan is collateralized by Leesburg Pike and requires equal monthly principal and interest payments of $135,000 based upon a 25-year amortization schedule and a final payment of $11.5 million at loan maturity. Principal of $373,000 was amortized during 2014.

(r)	The loan is collateralized by Village Center and requires equal monthly principal and interest payments of $119,000 based upon a 25-year amortization schedule and a final payment of $10.1 million at loan maturity. Principal of $314,000 was amortized during 2014.

(s)	The loan is collateralized by White Oak and requires equal monthly principal and interest payments of $193,000 based upon a 24.4 year weighted amortization schedule and a final payment of $18.5 million at loan maturity. The loan was previously collateralized by Van Ness Square. During 2012, the Company substituted White Oak as the collateral and borrowed an additional $10.5 million. Principal of $514,000 was amortized during 2014.

(t)	The loan is collateralized by Avenel Business Park and requires equal monthly principal and interest payments of $246,000 based upon a 25-year amortization schedule and a final payment of $20.9 million at loan maturity. Principal of $664,000 was amortized during 2014.

(u)	The loan is collateralized by Ashburn Village and requires equal monthly principal and interest payments of $240,000 based upon a 25-year amortization schedule and a final payment of $20.5 million at loan maturity. Principal of $641,000 was amortized during 2014.

(v)	The loan is collateralized by Ravenwood and requires equal monthly principal and interest payments of $111,000 based upon a 25-year amortization schedule and a final payment of $10.1 million at loan maturity. Principal of $352,000 was amortized during 2014.

(w)	The loan is collateralized by Clarendon Center and requires equal monthly principal and interest payments of $753,000 based upon a 25-year amortization schedule and a final payment of $70.5 million at loan maturity. Principal of $2.8 million was amortized during 2014.

(x)	The loan is collateralized by Severna Park MarketPlace and requires equal monthly principal and interest payments of $207,000 based upon a 25-year amortization schedule and a final payment of $20.3 million at loan maturity. Principal of $950,000 was amortized during 2014.

(y)	The loan is collateralized by Kentlands Square II and requires equal monthly principal and interest payments of $240,000 based upon a 25-year amortization schedule and a final payment of $23.1 million at loan maturity. Principal of $1,042,000 was amortized during 2014.

(z)	The loan is collateralized by Cranberry Square and requires equal monthly principal and interest payments of $113,000 based upon a 25-year amortization schedule and a final payment of $10.9 million at loan maturity. Principal of $473,000 was amortized during 2014.

(aa)	The loan in the original amount of $73.0 million closed in May 2012, is collateralized by Seven Corners and requires equal monthly principal and interest payments of $463,200 based upon a 25-year amortization schedule and a final payment of $42.3 million at loan maturity. Principal of $1.5 million was amortized during 2014.

(bb)	The loan is collateralized by Hampshire Langley and requires equal monthly principal and interest payments of $95,400 based upon a 25 -year amortization schedule and a final payment of $9.5 million at loan maturity. Principal of $437,000 was amortized in 2014.

(cc)	The loan is collateralized by Beacon Center and requires equal monthly principal and interest payments of $203,200 based upon a 20-year amortization schedule and a final payment of $11.4 million at loan maturity. Principal of $1,251,000 was amortized in 2014.

(dd)	The loan is collateralized by Seabreeze Plaza and requires equal monthly principal and interest payments of $94,900 based upon a 25-year amortization schedule and a final payment of $9.5 million at loan maturity. Principal of $433,000 was amortized in 2014.

(ee)	The loan is a $71.6 million construction-to-permanent facility that is collateralized by and will finance a portion of the construction costs of Park Van Ness. During the construction period, interest will be funded by the loan. After conversion to a permanent loan, monthly principal and interest payments totaling $413,500 will be required based upon a 25-year amortization schedule. A final payment of $39.6 million will be due at maturity.

(ff)	The Company entered into a sale-leaseback transaction with its Olney property and is accounting for that transaction as a secured financing. The arrangement requires monthly payments of $60,400 which increase by 1.5% on May 1, 2015, and every May 1 thereafter. The arrangement provides for a final payment of $14.7 million and has an implicit interest rate of 8.0%. Negative amortization in 2014 totaled $119,000.

(gg)	The loan is a $275.0 million unsecured revolving credit facility. Interest accrues at a rate equal to the sum of one-month LIBOR plus a spread of 145 basis points. The line may be extended at the Company’s option for one year with payment of a fee of 0.15%. Monthly payments, if required, are interest only and vary depending upon the amount outstanding and the applicable interest rate for any given month.

(hh)	The loan is collateralized by Northrock and requires monthly principal and interest payments of approximately $47,000 and a final payment of $14.2 million at maturity. Principal of $277,000 was amortized during 2014.

(ii)	The loan is collateralized by Metro Pike Center and requires monthly principal and interest payments of approximately $48,000 and a final payment of $14.8 million at loan maturity. Principal of $288,000 was amortized during 2014.
Scheduled Maturities of All Debt, Including Scheduled Principal Amortization	As of December 31, 2014, the scheduled maturities of all debt including scheduled principal amortization for years ended December 31 are as follows:


	(in thousands)	Balloon				Scheduled				Total
		Payments				Principal
						Amortization
	2015	$	14,885			$	23,192			$	38,077

	2016	28,879				23,496				52,375

	2017	—				24,679				24,679

	2018	70,748			(a)	24,822				95,570

	2019	60,794				23,489				84,283

	Thereafter	426,652				135,752				562,404

		$	601,958			$	255,430			$	857,388

	(a) Includes $43.0 million outstanding under the line of credit.
Interest Expense and Amortization of Deferred Debt Costs	The components of interest expense are set forth below.


	(in thousands)	Year ended December 31,
		2014				2013				2012
	Interest incurred	$	45,396			$	45,502			$	48,010

	Amortization of deferred debt costs	1,327				1,257				1,576

	Capitalized interest	(689		)		(170		)		(42		)
	Total	$	46,034			$	46,589			$	49,544

Lease_Agreements_Tables

Lease Agreements (Tables)	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Future Contractual Payments Under Noncancelable Leases	Future contractual payments under noncancelable leases for years ended December 31 (which exclude the effect of straight-line rents), are as follows:


	(in thousands)
	2015	$	152,661

	2016	135,703

	2017	116,025

	2018	96,439

	2019	73,626

	Thereafter	275,551

		$	850,005

LongTerm_Lease_Obligations_Tab

Long-Term Lease Obligations (Tables)	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Future Minimum Rental Commitments Under Ground Leases	The future minimum rental commitments under these ground leases are as follows:



		Year ending December 31,
	(In thousands)	2015		2016		2017		2018		2019		Thereafter		Total
	Beacon Center	$	60	$	60	$	60	$	60	$	60	$	2,541	$	2,841

	Olney	56		56		56		56		57		3,760		4,041

	Southdale	60		60		60		60		60		2,885		3,185

	Total	$	176	$	176	$	176	$	176	$	177	$	9,186	$	10,067

Stock_Option_Plan_Tables

Stock Option Plan (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Options Issued	The following table summarizes the amount and activity of each grant, the total value and variables used in the computation and the amount expensed and included in general and administrative expense in the Consolidated Statements of Operations for the years ended December 31, 2014, 2013 and 2012:



	SAUL CENTERS, INC.
	Notes to Consolidated Financial Statements
	Stock options issued

		Directors
	Grant date	5/6/05				5/1/06				4/27/07				4/25/08				4/24/09				5/7/10				5/13/11			5/4/12			5/10/13			5/9/14				Subtotals
	Total grant	30,000				30,000				30,000				30,000				32,500				32,500				32,500			35,000			35,000			30,000				317,500

	Vested	30,000				30,000				30,000				30,000				32,500				32,500				32,500			35,000			35,000			30,000				317,500

	Exercised	22,500				10,000				—				—				20,000				10,000				10,000			10,000			7,500			—				90,000

	Forfeited	—				2,500				7,500				7,500				—				2,500				2,500			—			—			—				22,500

	Exercisable at December 31, 2014	7,500				17,500				22,500				22,500				12,500				20,000				20,000			25,000			27,500			30,000				205,000

	Remaining unexercised	7,500				17,500				22,500				22,500				12,500				20,000				20,000			25,000			27,500			30,000				205,000

	Exercise price	$	33.22			$	40.35			$	54.17			$	50.15			$	32.68			$	38.76			$	41.82		$	39.29		$	44.42		$	47.03

	Volatility	0.198				0.206				0.225				0.237				0.344				0.369				0.358			0.348			0.333			0.173

	Expected life (years)	10				9				8				7				6				5				5			5			5			5

	Assumed yield	6.91		%		5.93		%		4.39		%		4.09		%		4.54		%		4.23		%		4.16		%	4.61		%	4.53		%	4.48		%
	Risk-free rate	4.28		%		5.11		%		4.65		%		3.49		%		2.19		%		2.17		%		1.86		%	0.78		%	0.82		%	1.63		%
	Total value at grant date	$	71,100			$	143,400			$	285,300			$	254,700			$	222,950			$	287,950			$	297,375		$	257,250		$	278,250		$	109,500			$	2,207,775

	Expensed in previous years	71,100				143,400				285,300				254,700				222,950				287,950				297,375			—			—			—				1,562,775

	Expensed in 2012	—				—				—				—				—				—				—			257,250			—			—				257,250

	Expensed in 2013	—				—				—				—				—				—				—			—			278,250			—				278,250

	Expensed in 2014	—				—				—				—				—				—				—			—			—			109,500				109,500

	Future expense	—				—				—				—				—				—				—			—			—			—				—

		Officers

	Grant date	5/6/05				4/27/07				5/13/11				5/4/12				5/10/13				5/9/14				Subtotals													Grand Totals
	Total grant	132,500				135,000				162,500				242,500				202,500				170,000				1,045,000													1,362,500

	Vested	118,750				67,500				105,625				56,250				50,625				—				398,750													716,250

	Exercised	115,750				3,528				46,889				30,000				15,625				—				211,792													301,792

	Forfeited	13,750				67,500				43,750				135,000				30,000				—				290,000													312,500

	Exercisable at December 31, 2014	3,000				63,972				47,486				26,250				35,000				—				175,708													380,708

	Remaining unexercised	3,000				63,972				71,861				77,500				156,875				170,000				543,208													748,208

	Exercise price	$	33.22			$	54.17			$	41.82			$	39.29			$	44.42			$	47.03

	Volatility	0.207				0.233				0.33				0.315				0.304				0.306

	Expected life (years)	8				6.5				8				8				8				7

	Assumed yield	6.37		%		4.13		%		4.81		%		5.28		%		5.12		%		4.89		%
Risk-free rate	4.15		%		4.61		%		2.75		%		1.49		%		1.49		%		2.17		%
Gross value at grant date	$	413,400			$	1,339,200			$	1,366,625			$	1,518,050			$	1,401,300			$	1,349,800			$	7,388,375												$	9,596,150

Estimated forfeitures	35,100				62,000				387,550				889,690				280,468				168,749				1,823,557													1,823,557

Expensed in previous years	378,300				1,277,200				186,347				—				—				—				1,841,847													3,404,622

Expensed in 2012					—				270,391				104,724				—				—				375,115													632,365

Expensed in 2013					—				235,350				157,083				209,027				—				601,460													879,710

Expensed in 2014	—				—				217,475				157,092				283,910				196,848				855,325													964,825

Future expense	—				—				69,512				209,461				627,895				984,203				1,891,071													1,891,071

Weighted average term of remaining future expense					2.7			years

Summary of Option Activity	The table below summarizes the option activity for the years 2014, 2013, and 2012:


		2014							2013							2012
		Shares			Weighted				Shares			Weighted				Shares			Weighted
					Average							Average							Average
					Exercise							Exercise							Exercise
					Price							Price							Price
	Outstanding at January 1	753,625			$	42.55			570,840			$	41.04			674,585			$	40.4

	Granted	200,000			47.03				237,500			44.42				277,500			39.29

	Exercised	(167,917	)		37.71				(49,715	)		33.15				(149,995	)		31.03

	Expired/Forfeited	(37,500	)		43.56				(5,000	)		52.16				(231,250	)		43.56

	Outstanding December 31	748,208			44.79				753,625			42.55				570,840			41.04

	Exercisable at December 31	380,708			44.85				413,000			42.42				377,715			41.41

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Changes in Fair Value of Swaps	The following chart summarizes the changes in fair value of the Company’s swaps for the indicated periods.



	(Dollars in thousands)	Year ended December 31,
		2014			2013			2012
	Increase (decrease) in fair value:
	Recognized in earnings	$	(10	)	$	(7	)	$	36

	Recognized in other comprehensive income	(675		)	2,897			(932		)

	Total	$	(685	)	$	2,890		$	(896	)

Distributions_Tables

Distributions (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Summary of Distributions Paid Including Activity in Plan as well as Limited Partnership Units Issued from Reinvestment of Unit Distributions	The following summarizes distributions paid during the years ended December 31, 2014, 2013, and 2012, and includes activity in the Plan as well as limited partnership units issued from the reinvestment of unit distributions:


		Total Distributions to						Dividend Reinvestments
	(Dollars in thousands, except per share amounts)	Preferred		Common		Limited		Common	Discounted		Limited Partnership Units Issued	Average Unit Price
		Stockholders		Stockholders		Partnership		Stock Shares	Share Price
						Unitholders		Issued
	Distributions during 2014
	October 31	$	3,856	$	8,348	$	2,879	40,142	$	52.71

	July 31	3,206		8,314		2,879		57,696	46.79

	April 30	3,206		8,269		2,838		60,212	44.14		104,831	$	44.77

	January 31	3,206		7,415		2,521		39,588	45.15		91,352	45.8

	Total 2014	$	13,474	$	32,346	$	11,117	197,638			196,183

	Distributions during 2013

	October 31	$	3,206	$	7,388	$	2,489	48,836	$	46.27	88,309	$	46.93

	July 31	3,206		7,327		2,489		138,019	45.21

	April 30	4,364		7,272		2,489		142,839	42.85

	January 31	3,785		7,218		2,489		145,468	41.67

	Total 2013	$	14,561	$	29,205	$	9,956	475,162			88,309

	Distributions during 2012

	October 31	$	3,785	$	7,120	$	2,489	141,960	42.23

	July 31	3,785		7,063		2,489		144,881	40.43

	April 30	3,785		7,005		2,489		145,118	38.93

	January 31	3,785		6,947		2,489		163,429	34.44

	Total 2012	$	15,140	$	28,135	$	9,956	595,388

Interim_Results_Unaudited_Tabl

Interim Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Summary of Results of Operations for Quarterly Periods	The following summary presents the results of operations of the Company for the quarterly periods of calendar years 2014 and 2013.


	(In thousands, except per share amounts)	2014
		1st Quarter			2nd Quarter		3rd Quarter		4th Quarter
	Revenue	$	52,947		$	52,286	$	50,595	$	51,264

	Operating income before loss on early extinguishment of debt, gain on casualty settlement, and noncontrolling interests	12,713			14,423		12,479		12,314

	Gain on sales of properties	—			6,069		—		—

	Net income attributable to Saul Centers, Inc.	10,287			16,054		10,106		10,496

	Net income available to common shareholders	7,081			12,847		6,900		5,274

	Net income available to common shareholders per diluted share	0.34			0.62		0.33		0.25





	(In thousands, except per share amounts)	2013
		1st Quarter			2nd Quarter		3rd Quarter		4th Quarter
	Revenue	$	49,186		$	48,809	$	49,756	$	50,146

	Operating income before loss on early extinguishment of debt, gain on casualty settlement, and noncontrolling interests	3,388			7,711		11,959		12,211

	Net income attributable to Saul Centers, Inc.	4,984			6,594		9,398		9,896

	Net income (loss) available to common shareholders.	(4,608		)	3,387		6,192		6,690

	Net income (loss) available to common shareholders per diluted share	(0.23		)	0.17		0.3		0.33

Business_Segments_Tables

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Business Segments

	SAUL CENTERS, INC.
	Notes to Consolidated Financial Statements
	(In thousands)	Shopping				Mixed-Use				Corporate				Consolidated
	As of or for the year ended December 31, 2014	Centers				Properties				and Other				Totals
	Real estate rental operations:
	Revenue	$	154,385			$	52,632			$	75			$	207,092

	Expenses	(33,781		)		(15,732		)		—				(49,513		)

	Income from real estate	120,604				36,900				75				157,579

	Interest expense and amortization of deferred debt costs	—				—				(46,034		)		(46,034		)

	General and administrative	—				—				(16,961		)		(16,961		)

	Subtotal	120,604				36,900				(62,920		)		94,584

	Depreciation and amortization of deferred leasing costs	(28,082		)		(13,121		)		—				(41,203		)

	Acquisition related costs	(949		)		—				—				(949		)

	Predevelopment expenses	—				(503		)		—				(503		)

	Change in fair value of derivatives	—				—				(10		)		(10		)

	Gain on sale of property	6,069				—				—				6,069

	Net income (loss)	$	97,642			$	23,276			$	(62,930	)		$	57,988

	Capital investment	$	66,508			$	23,760			$	—			$	90,268

	Total assets	$	946,819			$	307,901			$	12,267			$	1,266,987


	As of or for the year ended December 31, 2013
	Real estate rental operations:
	Revenue	$	145,219			$	52,609			$	69			$	197,897

	Expenses	(30,729		)		(17,213		)		—				(47,942		)

	Income from real estate	114,490				35,396				69				149,955

	Interest expense and amortization of deferred debt costs	—				—				(46,589		)		(46,589		)

	General and administrative	—				—				(14,951		)		(14,951		)

	Subtotal	114,490				35,396				(61,471		)		88,415

	Depreciation and amortization of deferred leasing costs	(27,340		)		(21,790		)		—				(49,130		)

	Acquisition related costs	(106		)		—				—				(106		)

	Predevelopment expenses	—				(3,910		)		—				(3,910		)

	Change in fair value of derivatives	—				—				(7		)		(7		)

	Loss on early extinguishment of debt	—				—				(497		)		(497		)

	Gain on casualty settlement	77				—				—				77

	Net income (loss)	$	87,121			$	9,696			$	(61,975	)		$	34,842

Capital investment	$	18,232			$	8,207			$	—			$	26,439

Total assets	$	888,109			$	293,512			$	17,054			$	1,198,675




SAUL CENTERS, INC.
Notes to Consolidated Financial Statements (continued)
(In thousands)	Shopping				Mixed-Use				Corporate				Consolidated
As of or for the year ended December 31, 2012	Centers				Properties				and Other				Totals
Real estate rental operations:
Revenue	$	137,647			$	52,309			$	136			$	190,092

Expenses	(30,139		)		(17,131		)		—				(47,270		)

Income from real estate	107,508				35,178				136				142,822

Interest expense and amortization of deferred debt costs	—				—				(49,544		)		(49,544		)

General and administrative	—				—				(14,274		)		(14,274		)

Subtotal	107,508				35,178				(63,682		)		79,004

Depreciation and amortization of deferred leasing costs	(25,667		)		(14,445		)		—				(40,112		)

Acquisition related costs	(1,129		)		—				—				(1,129		)

Predevelopment expenses	—				(2,667		)		—				(2,667		)

Change in fair value of derivatives	—				—				36				36

Gain on casualty settlement	219				—				—				219

Gains on sales of properties	4,510				—				—				4,510

Loss from operations of property sold	(81		)		—				—				(81		)

Net income (loss)	$	85,360			$	18,066			$	(63,646	)		$	39,780

Capital investment	$	46,353			$	8,290			$	—			$	54,643

Total assets	$	894,027			$	301,355			$	11,927			$	1,207,309

Recovered_Sheet1

Organization, Formation And Basis of Presentation - Additional Information (Detail)	Dec. 31, 2014
	partnership
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Distribution of REIT taxable income (excluding net capital gains) to its stockholders	90.00%
Number of partnerships	2
Shopping Centers
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of real estate properties	50
Mixed-Use Properties
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of real estate properties	6
Non-operating Development Properties
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of real estate properties	3

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended				12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	tenant				tenant
	store				store
Significant Accounting Policies [Line Items]
Number of shopping centers	32				32
Number of tenants	2				2
Interest expense capitalized					$689,000	$170,000	$42,300
Depreciation expense and amortization of leasehold improvements					35,933,000	43,204,000	34,565,000
Repairs and maintenance expense					11,900,000	10,300,000	9,900,000
Deferred leasing costs, net	26,928,000				26,928,000	26,052,000
Accumulated amortization deferred leasing cost	21,600,000				21,600,000	16,600,000
Amortization expense deferred leasing cost					5,300,000	5,900,000	5,500,000
Allowance for doubtful accounts receivables	677,000				677,000	572,000	1,208,000	671,000
Accounts receivable, net representing rental income accrued	38,700,000				38,700,000	37,200,000
Allowance for doubtful accounts receivables representing rental income accrued	300,000				300,000	500,000
Deferred debt costs, net	9,874,000				9,874,000	9,675,000
Accumulated amortization deferred leasing cost	5,900,000				5,900,000	4,500,000
Proceeds from sale of property					6,679,000	0	5,818,000
Gain on sales of properties	0	0	6,069,000	0	0	0	4,510,000
Accrued penalties and interest	0				0	0	0
Tax basis of the company's real estate investments	1,200,000,000				1,200,000,000	1,100,000,000
Shares issued to directors, shares					172,887	56,002	158,219
Percentage of ownership in Operating Partnership					74.20%
Options
Significant Accounting Policies [Line Items]
Antidilutive options (in shares)					106,875	112,500	117,500
Director
Significant Accounting Policies [Line Items]
Shares credited to deferred fee accounts					232,262
Shares issued to directors, shares					200	200	200
Shares issued to directors, value					112,900	124,400	110,000
West Park
Significant Accounting Policies [Line Items]
Name of property							West Park
Proceeds from sale of property							2,000,000
Gain on sales of properties							1,100,000
Belvedere
Significant Accounting Policies [Line Items]
Name of property							Belvedere
Proceeds from sale of property							4,000,000
Gain on sales of properties							$3,400,000
Minimum
Significant Accounting Policies [Line Items]
Percentage of total revenue					2.50%
Minimum \| Building
Significant Accounting Policies [Line Items]
Estimated useful life					35 years
Maximum \| Building
Significant Accounting Policies [Line Items]
Estimated useful life					50 years
Maximum \| Building Improvements
Significant Accounting Policies [Line Items]
Estimated useful life					20 years
Giant Food
Significant Accounting Policies [Line Items]
Percentage of total revenue					4.50%
Number of shopping centers					9
Safeway
Significant Accounting Policies [Line Items]
Percentage of total revenue					2.50%
Number of shopping centers					8

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Construction in Progress (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Construction in progress	$30,261	$9,867
Park Van Ness
Property, Plant and Equipment [Line Items]
Construction in progress	26,998	7,901
Other
Property, Plant and Equipment [Line Items]
Construction in progress	$3,263	$1,966

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	$572	$1,208	$671
Provision for Credit Losses	680	968	1,160
Charge-offs	-575	-1,604	-623
Ending Balance	$677	$572	$1,208

Summary_of_Significant_Account6

Summary of Significant Accounting Policies - Basic and Diluted Shares Outstanding (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Weighted average common shares outstanding - Basic	20,772	20,364	19,649
Effect of dilutive options (in shares)	49	37	51
Weighted average common shares outstanding - Diluted	20,821	20,401	19,700
Average share price (in usd per share)	$49.09	$45.44	$40.94

Real_Estate_Acquired_Additiona

Real Estate Acquired - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2012	Jan. 31, 2014	Apr. 30, 2014	Dec. 31, 2014	Aug. 31, 2014	Aug. 31, 2013	Dec. 31, 2013
	property	Property	Property	Dec. 31, 2012	Jan. 31, 2014	Apr. 30, 2014	Dec. 31, 2014	Aug. 31, 2014	sqft	sqft
Business Acquisition [Line Items]
Aggregate cost	$68,000,000	$5,100,000	$34,100,000
Property acquisition costs	900,000	106,000	1,100,000	1,100,000			900,000			106,000
Number of properties acquired	5						5
Number of properties acquired		2	2	2						2
Purchase price allocated to buildings	4,873,000	2,000,000	3,800,000	3,800,000			4,873,000			2,000,000
Purchase price allocated to land	66,047,000	3,100,000	30,400,000	30,400,000			66,047,000			3,100,000
Purchase price allocated to below market lease	5,069,000		700,000	700,000			5,069,000
Business acquisition, intangible asset estimated useful life			3 years 1 month 6 days
Intangible liabilities gross carrying amount	29,900,000	24,800,000					29,900,000			24,800,000
Intangible liabilities, accumulated amortization	11,900,000	10,000,000					11,900,000			10,000,000
Accretion income, intangible liabilities	1,900,000	1,700,000	1,600,000
In-Place Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	2,099,000		500,000	500,000			2,099,000
Above Market Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	0						0
Intangible assets gross carrying amount	1,000,000	1,000,000					1,000,000			1,000,000
Intangible assets, accumulated amortization	996,700	974,100					996,700			974,100
Amortization expense of intangible assets	23,000	45,000	60,000
Lease Acquisition Costs
Business Acquisition [Line Items]
Intangible assets gross carrying amount	24,000,000	21,900,000					24,000,000			21,900,000
Intangible assets, accumulated amortization	18,000,000	16,700,000					18,000,000			16,700,000
Amortization expense of intangible assets	1,300,000	2,000,000	2,000,000
1500 Rockville Pike
Business Acquisition [Line Items]
Year of acquisition				31-Dec-12
Aggregate cost				22,400,000
Name of property				1500 Rockville Pike
Property acquisition costs			600,000	600,000
1580 Rockville Pike
Business Acquisition [Line Items]
Year of acquisition					31-Jan-14
Aggregate cost					8,000,000
Name of property					1580 Rockville Pike
Property acquisition costs					200,000
Purchase price allocated to buildings	2,200,000						2,200,000
Purchase price allocated to land	9,600,000						9,600,000
Purchase price allocated to below market lease	4,313,000						4,313,000
1580 Rockville Pike \| In-Place Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	513,000						513,000
1580 Rockville Pike \| Above Market Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	0						0
1582 Rockville Pike
Business Acquisition [Line Items]
Year of acquisition						30-Apr-14
Aggregate cost						11,000,000
Name of property						1582 Rockville Pike
Property acquisition costs						200,000
Purchase price allocated to buildings	828,000						828,000
Purchase price allocated to land	9,742,000						9,742,000
Purchase price allocated to below market lease	419,000						419,000
1582 Rockville Pike \| In-Place Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	849,000						849,000
1582 Rockville Pike \| Above Market Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	0						0
1584 Rockville Pike
Business Acquisition [Line Items]
Year of acquisition							31-Dec-14
Aggregate cost							6,200,000
Name of property							1584 Rockville Pike
Property acquisition costs	200,000						200,000
Purchase price allocated to buildings	440,000						440,000
Purchase price allocated to land	5,798,000						5,798,000
Purchase price allocated to below market lease	337,000						337,000
1584 Rockville Pike \| In-Place Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	249,000						249,000
1584 Rockville Pike \| Above Market Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	0						0
750 N. Glebe Road
Business Acquisition [Line Items]
Year of acquisition								31-Aug-14
Aggregate cost								40,000,000
Name of property								750 N. Glebe Road
Property acquisition costs								400,000
Purchase price allocated to buildings	1,327,000						1,327,000
Purchase price allocated to land	38,224,000						38,224,000
Purchase price allocated to below market lease	0						0
750 N. Glebe Road \| In-Place Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	449,000						449,000
750 N. Glebe Road \| Above Market Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	0						0
730 N. Glebe Road
Business Acquisition [Line Items]
Year of acquisition							31-Dec-14
Aggregate cost							2,800,000
Name of property							730 N. Glebe Road
Property acquisition costs	40,400						40,400
Purchase price allocated to buildings	78,000						78,000
Purchase price allocated to land	2,683,000						2,683,000
Purchase price allocated to below market lease	0						0
730 N. Glebe Road \| In-Place Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	39,000						39,000
730 N. Glebe Road \| Above Market Leases
Business Acquisition [Line Items]
Purchase price allocated to leases	0						0
5541 Nicholson Lane
Business Acquisition [Line Items]
Year of acquisition				31-Dec-12
Aggregate cost				11,700,000
Name of property				5541 Nicholson Lane
Property acquisition costs			500,000	500,000
Kentlands Pad
Business Acquisition [Line Items]
Year of acquisition									31-Aug-13
Aggregate cost									4,300,000
Property acquisition costs									106,000
Area of real estate property (in square feet)									7,100
Hunt Club Pad
Business Acquisition [Line Items]
Year of acquisition										31-Dec-13
Aggregate cost										$800,000
Area of real estate property (in square feet)		5,500								5,500

Real_Estate_Acquired_Allocatio

Real Estate Acquired - Allocation of Purchase Prices to Acquired Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
Land	$66,047	$3,100	$30,400
Buildings	4,873	2,000	3,800
Below Market Rents	-5,069		-700
Total Purchase Price	67,950
In-Place Leases
Business Acquisition [Line Items]
Intangible assets	2,099		500
Above Market Rents
Business Acquisition [Line Items]
Intangible assets	0
1580 Rockville Pike
Business Acquisition [Line Items]
Land	9,600
Buildings	2,200
Below Market Rents	-4,313
Total Purchase Price	8,000
1580 Rockville Pike \| In-Place Leases
Business Acquisition [Line Items]
Intangible assets	513
1580 Rockville Pike \| Above Market Rents
Business Acquisition [Line Items]
Intangible assets	0
1582 Rockville Pike
Business Acquisition [Line Items]
Land	9,742
Buildings	828
Below Market Rents	-419
Total Purchase Price	11,000
1582 Rockville Pike \| In-Place Leases
Business Acquisition [Line Items]
Intangible assets	849
1582 Rockville Pike \| Above Market Rents
Business Acquisition [Line Items]
Intangible assets	0
750 N. Glebe Road
Business Acquisition [Line Items]
Land	38,224
Buildings	1,327
Below Market Rents	0
Total Purchase Price	40,000
750 N. Glebe Road \| In-Place Leases
Business Acquisition [Line Items]
Intangible assets	449
750 N. Glebe Road \| Above Market Rents
Business Acquisition [Line Items]
Intangible assets	0
730 N. Glebe Road
Business Acquisition [Line Items]
Land	2,683
Buildings	78
Below Market Rents	0
Total Purchase Price	2,800
730 N. Glebe Road \| In-Place Leases
Business Acquisition [Line Items]
Intangible assets	39
730 N. Glebe Road \| Above Market Rents
Business Acquisition [Line Items]
Intangible assets	0
1584 Rockville Pike
Business Acquisition [Line Items]
Land	5,798
Buildings	440
Below Market Rents	-337
Total Purchase Price	6,150
1584 Rockville Pike \| In-Place Leases
Business Acquisition [Line Items]
Intangible assets	249
1584 Rockville Pike \| Above Market Rents
Business Acquisition [Line Items]
Intangible assets	$0

Real_Estate_Acquired_Amortizat

Real Estate Acquired - Amortization of Intangible Assets and Deferred Income Related to in Place Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified	Dec. 31, 2014
Below market leases
2015	$1,787
2016	1,722
2017	1,701
2018	1,617
2019	1,473
Thereafter	9,670
Total	17,970
Lease Acquisition Costs
Finite-Lived Intangible Assets [Line Items]
2015	1,252
2016	988
2017	796
2018	737
2019	550
Thereafter	1,739
Total	6,062
Above Market Leases
Finite-Lived Intangible Assets [Line Items]
2015	2
2016	1
2017	1
2018	1
2019	0
Thereafter	0
Total	$5

Noncontrolling_Interest_Holder1

Noncontrolling Interest - Holders of Convertible Limited Partnership Units in Operating Partnership - Additional Information (Detail) (Noncontrolling Interest)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Noncontrolling Interest
Noncontrolling Interest [Line Items]
Percentage of ownership interest of noncontrolling interest	25.80%
Limited partnership units	7,198,721
Limited partnership units, conversion ratio	1
Outstanding stock percent that should be acquired for rights to be exercised	39.90%
Limited partnership units convertible in to shares of common stock, eligible for conversion	814,000
Fully converted partnership units and diluted weighted average shares outstanding	27,977,500	27,330,100	26,613,900

Mortgage_Notes_Payable_Revolvi2

Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs - Additional Information (Detail) (USD $)

12 Months Ended

0 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Apr. 26, 2012

Feb. 27, 2013

Apr. 10, 2013

Apr. 11, 2012

Mar. 19, 2013

28-May-13

Sep. 04, 2013

Oct. 25, 2013

Jun. 24, 2014

Debt Instrument [Line Items]

Outstanding debt

$857,400,000

Fixed rate mortgages

808,997,000

820,068,000

Debt outstanding

857,388,000

820,100,000

Debt outstanding with fixed-rate

789,900,000

Debt outstanding with variable-rate

30,200,000

Line of credit facility, maximum borrowing capacity

231,600,000

Outstanding line of credit

43,000,000

Letter of credit facility

448,000

Guarantor obligations, maximum exposure

51,000,000

Debt instrument maturity term

8 years 8 months 21 days

[1]

Defeased mortgage loan

22,071,000

71,308,000

117,595,000

Proceeds from debt

[2]

101,600,000

83,500,000

Debt instrument fixed interest rate

3.65%

4.85%

Capitalization of debt issuance cost

1,300,000

3,200,000

2,200,000

White Oak Shopping Center

Debt Instrument [Line Items]

Debt instrument amount

10,500,000

Debt instrument fixed interest rate

8.11%

Principal amortization period

25 years

Debt instrument required final principal payment

18,500,000

Blended fixed interest rate

7.00%

Metro Pike Center

Debt Instrument [Line Items]

Debt instrument amount

15,600,000

Debt instrument, maturity year

2016

Principal amortization period

25 years

Debt instrument required final principal payment

14,800,000

Debt instrument, term

3 years

Interest rate spread on LIBOR

1.65%

Existing loan extension period

2 years

Repayment of debt

15,900,000

Northrock

Debt Instrument [Line Items]

Debt instrument amount

15,000,000

Debt instrument, maturity year

2016

Principal amortization period

25 years

Debt instrument required final principal payment

14,200,000

Debt instrument, term

3 years

Interest rate spread on LIBOR

1.65%

Existing loan extension period

2 years

Repayment of debt

15,000,000

Cruse Market Place

Debt Instrument [Line Items]

Repayment of debt

6,900,000

Northrock Loan

Debt Instrument [Line Items]

Guarantor obligations, maximum exposure

7,500,000

5.84% due May 2027 | Seven Corners Shopping Center

Debt Instrument [Line Items]

Debt instrument maturity term

15 years

Debt instrument amount

73,000,000

Debt instrument, maturity year

2027

Debt instrument fixed interest rate

5.84%

Principal amortization period

25 years

Defeased mortgage loan

63,000,000

Proceeds from debt

10,000,000

4.04% due April 2028 | Hampshire Langley

Debt Instrument [Line Items]

Debt instrument amount

18,000,000

Debt instrument, maturity year

2028

Debt instrument fixed interest rate

4.04%

Debt instrument required periodic principal and interest payment

95,400

Debt instrument required final principal payment

9,500,000

Debt instrument, term

15 years

3.51% due June 2028 | Beacon Center

Debt Instrument [Line Items]

Debt instrument amount

35,000,000

Debt instrument, maturity year

2028

Debt instrument fixed interest rate

3.51%

Debt instrument required periodic principal and interest payment

203,200

Principal amortization period

20 years

Debt instrument required final principal payment

11,400,000

Debt instrument, term

15 years

3.99% due September 2028 | Seabreeze Plaza

Debt Instrument [Line Items]

Debt instrument amount

18,000,000

Debt instrument, maturity year

2028

Debt instrument fixed interest rate

3.99%

Debt instrument, term

15 years

Repayment of debt

13,500,000

Payments of debt extinguishment costs

497,000

4.88% due September 2032 | Park Van Ness

Debt Instrument [Line Items]

Debt instrument fixed interest rate

4.88%

Principal amortization period

25 years

Unsecured Revolving Credit Facility

Debt Instrument [Line Items]

Line of credit facility, maximum borrowing capacity

275,000,000

Extension in line of credit facility period

1 year

Line of credit facility maturity date

23-Jun-18

Description of variable rate basis

one-month LIBOR

Fixed Rate Mortgage Notes Payable

Debt Instrument [Line Items]

Fixed rate mortgages

784,757,000

789,872,000

Debt instrument maturity term

9 years 3 months 0 days

[1]

Debt instrument fixed interest rate

5.70%

[1]

Fixed Rate Mortgage Notes Payable | White Oak Shopping Center

Debt Instrument [Line Items]

Debt instrument fixed interest rate

4.90%

Fixed Rate Mortgage Notes Payable | Metro Pike Center bank loan

Debt Instrument [Line Items]

Guarantor obligations, maximum exposure

7,800,000

Fixed Rate Mortgage Notes Payable | 5.84% due May 2027

Debt Instrument [Line Items]

Fixed rate mortgages

69,397,000

[3]

70,856,000

Debt instrument fixed interest rate

5.84%

Fixed Rate Mortgage Notes Payable | 5.84% due May 2027 | Seven Corners Shopping Center

Debt Instrument [Line Items]

Debt instrument amount

73,000,000

Debt instrument required periodic principal and interest payment

463,200

Principal amortization period

25 years

Debt instrument required final principal payment

42,300,000

Fixed Rate Mortgage Notes Payable | 4.04% due April 2028

Debt Instrument [Line Items]

Fixed rate mortgages

17,281,000

[4]

17,718,000

Debt instrument fixed interest rate

4.04%

Fixed Rate Mortgage Notes Payable | 4.04% due April 2028 | Hampshire Langley

Debt Instrument [Line Items]

Debt instrument required periodic principal and interest payment

95,400

Principal amortization period

25 years

Debt instrument required final principal payment

9,500,000

Fixed Rate Mortgage Notes Payable | 3.51% due June 2028

Debt Instrument [Line Items]

Fixed rate mortgages

33,140,000

[5]

34,391,000

Debt instrument fixed interest rate

3.51%

Fixed Rate Mortgage Notes Payable | 3.51% due June 2028 | Beacon Center

Debt Instrument [Line Items]

Debt instrument required periodic principal and interest payment

203,200

Principal amortization period

20 years

Debt instrument required final principal payment

11,400,000

Fixed Rate Mortgage Notes Payable | 3.99% due September 2028

Debt Instrument [Line Items]

Fixed rate mortgages

17,462,000

[6]

17,895,000

Debt instrument fixed interest rate

3.99%

Fixed Rate Mortgage Notes Payable | 3.99% due September 2028 | Seabreeze Plaza

Debt Instrument [Line Items]

Debt instrument required periodic principal and interest payment

94,900

Principal amortization period

25 years

Debt instrument required final principal payment

9,500,000

Fixed Rate Mortgage Notes Payable | 4.88% due September 2032

Debt Instrument [Line Items]

Fixed rate mortgages

5,391,000

[7]

Debt instrument fixed interest rate

4.88%

Fixed Rate Mortgage Notes Payable | 4.88% due September 2032 | Park Van Ness

Debt Instrument [Line Items]

Debt instrument amount

71,580,000

Debt instrument required periodic principal and interest payment

413,500

Principal amortization period

25 years

Debt instrument required final principal payment

39,600,000

Variable Rate Loans Payable

Debt Instrument [Line Items]

Variable rate loans

72,631,000

30,196,000

Debt instrument maturity term

2 years 5 months 18 days

[1]

Interest rate spread on LIBOR

1.53%

Variable Rate Loans Payable | Northrock Loan

Debt Instrument [Line Items]

Variable rate loans

14,525,000

[8]

14,802,000

Interest rate spread on LIBOR

1.65%

Variable Rate Loans Payable | Northrock Loan | Northrock

Debt Instrument [Line Items]

Debt instrument required periodic principal and interest payment

47,000

Debt instrument required final principal payment

14,200,000

Variable Rate Loans Payable | Metro Pike Center bank loan

Debt Instrument [Line Items]

Variable rate loans

15,106,000

[9]

15,394,000

Interest rate spread on LIBOR

1.65%

Variable Rate Loans Payable | Metro Pike Center bank loan | Metro Pike Center

Debt Instrument [Line Items]

Debt instrument required periodic principal and interest payment

48,000

Debt instrument required final principal payment

14,800,000

LIBOR

Debt Instrument [Line Items]

Interest rate basis points

1.45%

Debt Covenant [Member]

Debt Instrument [Line Items]

Carrying value of properties collateralized

895,500,000

907,200,000

Debt covenant, percentage of net proceeds of additional equity issuance

80.00%

Credit agreement leverage ratio

60.00%

Interest coverage ratio required minimum

Required fixed charge coverage ratio

1.3

Minimum | Unsecured Revolving Credit Facility

Debt Instrument [Line Items]

Interest rate spread on LIBOR

1.45%

Minimum | LIBOR

Debt Instrument [Line Items]

Interest rate basis points

1.45%

Minimum | Debt Covenant [Member]

Debt Instrument [Line Items]

Debt covenant required net assets

$542,100,000

Maximum | Unsecured Revolving Credit Facility

Debt Instrument [Line Items]

Interest rate spread on LIBOR

2.00%

Maximum | LIBOR

Debt Instrument [Line Items]

Interest rate basis points

2.00%

[1]

Interest rate and scheduled maturity data presented as of DecemberB 31, 2014. Totals computed using weighted averages.

[2]

The 2014 acquisition of real estate and proceeds from notes payable each exclude $11,000 in connection with the sale and leaseback of the Company's Olney property.

[3]

The loan in the original amount of $73.0 million closed in May 2012, is collateralized by Seven Corners and requires equal monthly principal and interest payments of $463,200 based upon a 25-year amortization schedule and a final payment of $42.3B million at loan maturity. Principal of $1.5B million was amortized during 2014.

[4]

The loan is collateralized by Hampshire Langley and requires equal monthly principal and interest payments of $95,400 based upon a 25 -year amortization schedule and a final payment of $9.5B million at loan maturity. Principal of $437,000 was amortized in 2014.

[5]

The loan is collateralized by Beacon Center and requires equal monthly principal and interest payments of $203,200 based upon a 20-year amortization schedule and a final payment of $11.4B million at loan maturity. Principal of $1,251,000 was amortized in 2014.

[6]

The loan is collateralized by Seabreeze Plaza and requires equal monthly principal and interest payments of $94,900 based upon a 25-year amortization schedule and a final payment of $9.5B million at loan maturity. Principal of $433,000 was amortized in 2014.

[7]

The loan is a $71.6B million construction-to-permanent facility that is collateralized by and will finance a portion of the construction costs of Park Van Ness. During the construction period, interest will be funded by the loan. After conversion to a permanent loan, monthly principal and interest payments totaling $413,500 will be required based upon a 25-year amortization schedule. A final payment of $39.6B million will be due at maturity.

[8]

The loan is collateralized by Northrock and requires monthly principal and interest payments of approximately $47,000 and a final payment of $14.2B million at maturity. Principal of $277,000 was amortized during 2014.

[9]

The loan is collateralized by Metro Pike Center and requires monthly principal and interest payments of approximately $48,000 and a final payment of $14.8 million at loan maturity. Principal of $288,000 was amortized during 2014.

Mortgage_Notes_Payable_Revolvi3

Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs - Summary of Notes Payable (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Notes Payable [Line Items]
Fixed rate mortgages	$808,997		$820,068
Interest rate	3.65%		4.85%
Scheduled maturity period	8 years 8 months 21 days	[1]
Total notes payable	857,388		820,068
Interest rate during period	5.36%	[1]
Fixed Rate Mortgage Notes Payable
Notes Payable [Line Items]
Fixed rate mortgages	784,757		789,872
Interest rate	5.70%	[1]
Scheduled maturity period	9 years 3 months 0 days	[1]
Fixed Rate Mortgage Notes Payable \| 7.45% due June 2015
Notes Payable [Line Items]
Fixed rate mortgages	15,399	[2]	16,128
Interest rate	7.45%
Scheduled maturity	2015-06	[1]
Fixed Rate Mortgage Notes Payable \| 6.01% due February 2018
Notes Payable [Line Items]
Fixed rate mortgages	32,049	[3]	33,246
Interest rate	6.01%
Scheduled maturity	2018-02	[1]
Fixed Rate Mortgage Notes Payable \| 5.88% due January 2019
Notes Payable [Line Items]
Fixed rate mortgages	35,398	[4]	36,937
Interest rate	5.88%
Scheduled maturity	2019-01	[1]
Fixed Rate Mortgage Notes Payable \| 5.76% due May 2019
Notes Payable [Line Items]
Fixed rate mortgages	11,454	[5]	11,949
Interest rate	5.76%
Scheduled maturity	2019-05	[1]
Fixed Rate Mortgage Notes Payable \| 5.62% due July 2019
Notes Payable [Line Items]
Fixed rate mortgages	15,819	[6]	16,501
Interest rate	5.62%
Scheduled maturity	2019-07	[1]
Fixed Rate Mortgage Notes Payable \| 5.79% due September 2019
Notes Payable [Line Items]
Fixed rate mortgages	15,761	[7]	16,419
Interest rate	5.79%
Scheduled maturity	2019-09	[1]
Fixed Rate Mortgage Notes Payable \| 5.22% due January 2020
Notes Payable [Line Items]
Fixed rate mortgages	14,014	[8]	14,610
Interest rate	5.22%
Scheduled maturity	2020-01	[1]
Fixed Rate Mortgage Notes Payable \| 5.60% due May 2020
Notes Payable [Line Items]
Fixed rate mortgages	10,881	[9]	11,159
Interest rate	5.60%
Scheduled maturity	2020-05	[1]
Fixed Rate Mortgage Notes Payable \| 5.30% due June 2020
Notes Payable [Line Items]
Fixed rate mortgages	9,535	[10]	9,921
Interest rate	5.30%
Scheduled maturity	2020-06	[1]
Fixed Rate Mortgage Notes Payable \| 5.83% due July 2020
Notes Payable [Line Items]
Fixed rate mortgages	41,441	[11]	42,462
Interest rate	5.83%
Scheduled maturity	2020-07	[1]
Fixed Rate Mortgage Notes Payable \| 5.81% due February 2021
Notes Payable [Line Items]
Fixed rate mortgages	8,346	[12]	8,649
Interest rate	5.81%
Scheduled maturity	2021-02	[1]
Fixed Rate Mortgage Notes Payable \| 6.01% due August 2021
Notes Payable [Line Items]
Fixed rate mortgages	6,100	[13]	6,233
Interest rate	6.01%
Scheduled maturity	2021-08	[1]
Fixed Rate Mortgage Notes Payable \| 5.62% due June 2022
Notes Payable [Line Items]
Fixed rate mortgages	35,222	[14]	35,981
Interest rate	5.62%
Scheduled maturity	2022-06	[1]
Fixed Rate Mortgage Notes Payable \| 6.08% due September 2022
Notes Payable [Line Items]
Fixed rate mortgages	10,718	[15]	10,930
Interest rate	6.08%
Scheduled maturity	2022-09	[1]
Fixed Rate Mortgage Notes Payable \| 6.43% due April 2023
Notes Payable [Line Items]
Fixed rate mortgages	11,587	[16]	11,795
Interest rate	6.43%
Scheduled maturity	2023-04	[1]
Fixed Rate Mortgage Notes Payable \| 6.28% due February 2024
Notes Payable [Line Items]
Fixed rate mortgages	14,909	[17]	15,598
Interest rate	6.28%
Scheduled maturity	2024-02	[1]
Fixed Rate Mortgage Notes Payable \| 7.35% due June 2024
Notes Payable [Line Items]
Fixed rate mortgages	16,750	[18]	17,123
Interest rate	7.35%
Scheduled maturity	2024-06	[1]
Fixed Rate Mortgage Notes Payable \| 7.60% due June 2024
Notes Payable [Line Items]
Fixed rate mortgages	14,535	[19]	14,849
Interest rate	7.60%
Scheduled maturity	2024-06	[1]
Fixed Rate Mortgage Notes Payable \| 7.02% due July 2024
Notes Payable [Line Items]
Fixed rate mortgages	25,639	[20]	26,153
Interest rate	7.02%
Scheduled maturity	2024-07	[1]
Fixed Rate Mortgage Notes Payable \| 7.45% due July 2024
Notes Payable [Line Items]
Fixed rate mortgages	30,429	[21]	31,093
Interest rate	7.45%
Scheduled maturity	2024-07	[1]
Fixed Rate Mortgage Notes Payable \| 7.30% due January 2025
Notes Payable [Line Items]
Fixed rate mortgages	30,253	[22]	30,894
Interest rate	7.30%
Scheduled maturity	2025-01	[1]
Fixed Rate Mortgage Notes Payable \| 6.18% due January 2026
Notes Payable [Line Items]
Fixed rate mortgages	15,735	[23]	16,087
Interest rate	6.18%
Scheduled maturity	2026-01	[1]
Fixed Rate Mortgage Notes Payable \| 5.31% due April 2026
Notes Payable [Line Items]
Fixed rate mortgages	115,291	[24]	118,128
Interest rate	5.31%
Scheduled maturity	2026-04	[1]
Fixed Rate Mortgage Notes Payable \| 4.30% due October 2026
Notes Payable [Line Items]
Fixed rate mortgages	35,125	[25]	36,075
Interest rate	4.30%
Scheduled maturity	2026-10	[1]
Fixed Rate Mortgage Notes Payable \| 4.53% due November 2026
Notes Payable [Line Items]
Fixed rate mortgages	39,932	[26]	40,974
Interest rate	4.53%
Scheduled maturity	2026-11	[1]
Fixed Rate Mortgage Notes Payable \| 4.70% due December 2026
Notes Payable [Line Items]
Fixed rate mortgages	18,645	[27]	19,118
Interest rate	4.70%
Scheduled maturity	2026-12	[1]
Fixed Rate Mortgage Notes Payable \| 5.84% due May 2027
Notes Payable [Line Items]
Fixed rate mortgages	69,397	[28]	70,856
Interest rate	5.84%
Scheduled maturity	2027-05	[1]
Fixed Rate Mortgage Notes Payable \| 4.04% due April 2028
Notes Payable [Line Items]
Fixed rate mortgages	17,281	[29]	17,718
Interest rate	4.04%
Scheduled maturity	2028-04	[1]
Fixed Rate Mortgage Notes Payable \| 3.51% due June 2028
Notes Payable [Line Items]
Fixed rate mortgages	33,140	[30]	34,391
Interest rate	3.51%
Scheduled maturity	2028-06	[1]
Fixed Rate Mortgage Notes Payable \| 3.99% due September 2028
Notes Payable [Line Items]
Fixed rate mortgages	17,462	[31]	17,895
Interest rate	3.99%
Scheduled maturity	2028-09	[1]
Fixed Rate Mortgage Notes Payable \| 4.88% due September 2032
Notes Payable [Line Items]
Fixed rate mortgages	5,391	[32]	0
Interest rate	4.88%
Scheduled maturity	2032-09	[1]
Fixed Rate Mortgage Notes Payable \| 8.00% due April 2034
Notes Payable [Line Items]
Fixed rate mortgages	11,119	[33]	0
Interest rate	8.00%
Scheduled maturity	2034-04	[1]
Variable Rate Loans Payable
Notes Payable [Line Items]
Variable rate loans	72,631		30,196
Interest rate spread on LIBOR	1.53%
Scheduled maturity period	2 years 5 months 18 days	[1]
Variable Rate Loans Payable \| Revolving credit facility
Notes Payable [Line Items]
Scheduled maturity	2018-06	[1]
Variable rate loans	43,000	[34]	0
Interest rate spread on LIBOR	1.45%
Variable Rate Loans Payable \| Northrock loan
Notes Payable [Line Items]
Scheduled maturity	2016-02	[1]
Variable rate loans	14,525	[35]	14,802
Interest rate spread on LIBOR	1.65%
Variable Rate Loans Payable \| Metro Pike Center bank loan
Notes Payable [Line Items]
Scheduled maturity	2016-02	[1]
Variable rate loans	$15,106	[36]	$15,394
Interest rate spread on LIBOR	1.65%

[1]	Interest rate and scheduled maturity data presented as of DecemberB 31, 2014. Totals computed using weighted averages.
[2]	The loan is collateralized by Shops at Fairfax and Boulevard shopping centers and requires equal monthly principal and interest payments totaling $156,000 based upon a weighted average 23-year amortization schedule and a final payment of $15.2B million is due at loan maturity. Principal of $729,000 was amortized during 2014.
[3]	The loan is collateralized by Washington Square and requires equal monthly principal and interest payments of $264,000 based upon a 27.5-year amortization schedule and a final payment of $28.0B million at loan maturity. Principal of $1.2B million was amortized during 2014.
[4]	The loan is collateralized by three shopping centers, Broadlands Village, The Glen and Kentlands Square I, and requires equal monthly principal and interest payments of $306,000 based upon a 25-year amortization schedule and a final payment of $28.4B million at loan maturity. Principal of $1.5B million was amortized during 2014.
[5]	The loan is collateralized by Olde Forte Village and requires equal monthly principal and interest payments of $98,000 based upon a 25-year amortization schedule and a final payment of $9.0B million at loan maturity. Principal of $495,000 was amortized during 2014.
[6]	The loan is collateralized by Countryside and requires equal monthly principal and interest payments of $133,000 based upon a 25-year amortization schedule and a final payment of $12.3B million at loan maturity. Principal of $682,000 was amortized during 2014.
[7]	The loan is collateralized by Briggs Chaney MarketPlace and requires equal monthly principal and interest payments of $133,000 based upon a 25-year amortization schedule and a final payment of $12.2B million at loan maturity. Principal of $658,000 was amortized during 2014.
[8]	The loan is collateralized by Shops at Monocacy and requires equal monthly principal and interest payments of $112,000 based upon a 25-year amortization schedule and a final payment of $10.6B million at loan maturity. Principal of $596,000 was amortized during 2014.
[9]	The loan is collateralized by Boca Valley Plaza and requires equal monthly principal and interest payments of $75,000 based upon a 30-year amortization schedule and a final payment of $9.1B million at loan maturity. Principal of $278,000 was amortized during 2014.
[10]	The loan is collateralized by Palm Springs Center and requires equal monthly principal and interest payments of $75,000 based upon a 25-year amortization schedule and a final payment of $7.1B million at loan maturity. Principal of $386,000 was amortized during 2014.
[11]	The loan and a corresponding interest-rate swap closed on JuneB 29, 2010 and are collateralized by Thruway. On a combined basis, the loan and the interest-rate swap require equal monthly principal and interest payments of $289,000 based upon a 25-year amortization schedule and a final payment of $34.8B million at loan maturity. Principal of $1,021,000 was amortized during 2014.
[12]	The loan is collateralized by Jamestown Place and requires equal monthly principal and interest payments of $66,000 based upon a 25-year amortization schedule and a final payment of $6.1B million at loan maturity. Principal of $303,000 was amortized during 2014.
[13]	The loan is collateralized by Hunt Club Corners and requires equal monthly principal and interest payments of $42,000 based upon a 30-year amortization schedule and a final payment of $5.0B million, at loan maturity. Principal of $133,000 was amortized during 2014.
[14]	The loan is collateralized by Lansdowne Town Center and requires monthly principal and interest payments of $230,000 based on a 30-year amortization schedule and a final payment of $28.2B million at loan maturity. Principal of $759,000 was amortized during 2014.
[15]	The loan is collateralized by Orchard Park and requires equal monthly principal and interest payments of $73,000 based upon a 30-year amortization schedule and a final payment of $8.6B million at loan maturity. Principal of $212,000 was amortized during 2014.
[16]	The loan is collateralized by BJbs Wholesale and requires equal monthly principal and interest payments of $80,000 based upon a 30-year amortization schedule and a final payment of $9.3B million at loan maturity. Principal of $208,000 was amortized during 2014.
[17]	The loan is collateralized by Great Falls shopping center. The loan consists of three notes which require equal monthly principal and interest payments of $138,000 based upon a weighted average 26-year amortization schedule and a final payment of $6.3B million at maturity. Principal of $689,000 was amortized during 2014.
[18]	The loan is collateralized by Leesburg Pike and requires equal monthly principal and interest payments of $135,000 based upon a 25-year amortization schedule and a final payment of $11.5B million at loan maturity. Principal of $373,000 was amortized during 2014.
[19]	The loan is collateralized by Village Center and requires equal monthly principal and interest payments of $119,000 based upon a 25-year amortization schedule and a final payment of $10.1B million at loan maturity. Principal of $314,000 was amortized during 2014.
[20]	The loan is collateralized by White Oak and requires equal monthly principal and interest payments of $193,000 based upon a 24.4 year weighted amortization schedule and a final payment of $18.5B million at loan maturity. The loan was previously collateralized by Van Ness Square. During 2012, the Company substituted White Oak as the collateral and borrowed an additional $10.5 million. Principal of $514,000 was amortized during 2014.
[21]	The loan is collateralized by Avenel Business Park and requires equal monthly principal and interest payments of $246,000 based upon a 25-year amortization schedule and a final payment of $20.9B million at loan maturity. Principal of $664,000 was amortized during 2014.
[22]	The loan is collateralized by Ashburn Village and requires equal monthly principal and interest payments of $240,000 based upon a 25-year amortization schedule and a final payment of $20.5B million at loan maturity. Principal of $641,000 was amortized during 2014.
[23]	The loan is collateralized by Ravenwood and requires equal monthly principal and interest payments of $111,000 based upon a 25-year amortization schedule and a final payment of $10.1B million at loan maturity. Principal of $352,000 was amortized during 2014.
[24]	The loan is collateralized by Clarendon Center and requires equal monthly principal and interest payments of $753,000 based upon a 25-year amortization schedule and a final payment of $70.5B million at loan maturity. Principal of $2.8B million was amortized during 2014.
[25]	The loan is collateralized by Severna Park MarketPlace and requires equal monthly principal and interest payments of $207,000 based upon a 25-year amortization schedule and a final payment of $20.3B million at loan maturity. Principal of $950,000 was amortized during 2014.
[26]	The loan is collateralized by Kentlands Square II and requires equal monthly principal and interest payments of $240,000 based upon a 25-year amortization schedule and a final payment of $23.1B million at loan maturity. Principal of $1,042,000 was amortized during 2014.
[27]	The loan is collateralized by Cranberry Square and requires equal monthly principal and interest payments of $113,000 based upon a 25-year amortization schedule and a final payment of $10.9B million at loan maturity. Principal of $473,000 was amortized during 2014.
[28]	The loan in the original amount of $73.0 million closed in May 2012, is collateralized by Seven Corners and requires equal monthly principal and interest payments of $463,200 based upon a 25-year amortization schedule and a final payment of $42.3B million at loan maturity. Principal of $1.5B million was amortized during 2014.
[29]	The loan is collateralized by Hampshire Langley and requires equal monthly principal and interest payments of $95,400 based upon a 25 -year amortization schedule and a final payment of $9.5B million at loan maturity. Principal of $437,000 was amortized in 2014.
[30]	The loan is collateralized by Beacon Center and requires equal monthly principal and interest payments of $203,200 based upon a 20-year amortization schedule and a final payment of $11.4B million at loan maturity. Principal of $1,251,000 was amortized in 2014.
[31]	The loan is collateralized by Seabreeze Plaza and requires equal monthly principal and interest payments of $94,900 based upon a 25-year amortization schedule and a final payment of $9.5B million at loan maturity. Principal of $433,000 was amortized in 2014.
[32]	The loan is a $71.6B million construction-to-permanent facility that is collateralized by and will finance a portion of the construction costs of Park Van Ness. During the construction period, interest will be funded by the loan. After conversion to a permanent loan, monthly principal and interest payments totaling $413,500 will be required based upon a 25-year amortization schedule. A final payment of $39.6B million will be due at maturity.
[33]	The Company entered into a sale-leaseback transaction with its Olney property and is accounting for that transaction as a secured financing. The arrangement requires monthly payments of $60,400 which increase by 1.5% on May 1, 2015, and every May 1 thereafter. The arrangement provides for a final payment of $14.7 million and has an implicit interest rate of 8.0%. Negative amortization in 2014 totaled $119,000.
[34]	The loan is a $275.0B million unsecured revolving credit facility. Interest accrues at a rate equal to the sum of one-month LIBOR plus a spread of 145 basis points. The line may be extended at the Companybs option for one year with payment of a fee of 0.15%. Monthly payments, if required, are interest only and vary depending upon the amount outstanding and the applicable interest rate for any given month.
[35]	The loan is collateralized by Northrock and requires monthly principal and interest payments of approximately $47,000 and a final payment of $14.2B million at maturity. Principal of $277,000 was amortized during 2014.
[36]	The loan is collateralized by Metro Pike Center and requires monthly principal and interest payments of approximately $48,000 and a final payment of $14.8 million at loan maturity. Principal of $288,000 was amortized during 2014.

Mortgage_Notes_Payable_Revolvi4

Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs - Summary of Notes Payable (Additional Information) (Detail) (USD $)	0 Months Ended						12 Months Ended		0 Months Ended
	Apr. 26, 2012	Feb. 27, 2013	Apr. 11, 2012	Mar. 19, 2013	28-May-13	Oct. 25, 2013	Dec. 31, 2014		Sep. 04, 2013	Dec. 31, 2013	Dec. 31, 2012
Notes Payable [Line Items]
Interest rate							3.65%			4.85%
Line of credit facility, maximum borrowing capacity							$231,600,000
White Oak Shopping Center
Notes Payable [Line Items]
Amortization period	25 years
Debt instrument final payment	18,500,000
Debt instrument amount	10,500,000
Northrock
Notes Payable [Line Items]
Amortization period		25 years
Debt instrument final payment		14,200,000
Debt instrument amount		15,000,000
Interest rate spread on LIBOR		1.65%
Metro Pike Center
Notes Payable [Line Items]
Amortization period		25 years
Debt instrument final payment		14,800,000
Debt instrument amount		15,600,000
Interest rate spread on LIBOR		1.65%
5.84% due May 2027 \| Seven Corners
Notes Payable [Line Items]
Amortization period			25 years
Debt instrument amount			73,000,000
4.04% due April 2028 \| Hampshire Langley
Notes Payable [Line Items]
Principal and interest payments				95,400
Debt instrument final payment				9,500,000
Debt instrument amount				18,000,000
3.51% due June 2028 \| Beacon Center
Notes Payable [Line Items]
Principal and interest payments					203,200
Amortization period					20 years
Debt instrument final payment					11,400,000
Debt instrument amount					35,000,000
3.99% due September 2028 \| Seabreeze Plaza
Notes Payable [Line Items]
Debt instrument amount									18,000,000
4.88% due September 2032 \| Park Van Ness
Notes Payable [Line Items]
Amortization period						25 years
Fixed Rate Mortgage Notes Payable
Notes Payable [Line Items]
Interest rate							5.70%	[1]
Fixed Rate Mortgage Notes Payable \| White Oak Shopping Center
Notes Payable [Line Items]
Interest rate	4.90%
Fixed Rate Mortgage Notes Payable \| 7.45% due June 2015
Notes Payable [Line Items]
Interest rate							7.45%
Fixed Rate Mortgage Notes Payable \| 7.45% due June 2015 \| Shops at Fairfax and Boulevard
Notes Payable [Line Items]
Principal and interest payments							156,000
Amortization period							23 years
Debt instrument final payment							15,200,000
Amortization of principal							729,000
Fixed Rate Mortgage Notes Payable \| 6.01% due February 2018
Notes Payable [Line Items]
Interest rate							6.01%
Fixed Rate Mortgage Notes Payable \| 6.01% due February 2018 \| Washington Square
Notes Payable [Line Items]
Principal and interest payments							264,000
Amortization period							27 years 6 months
Debt instrument final payment							28,000,000
Amortization of principal							1,200,000
Fixed Rate Mortgage Notes Payable \| 5.88% due January 2019
Notes Payable [Line Items]
Interest rate							5.88%
Fixed Rate Mortgage Notes Payable \| 5.88% due January 2019 \| Broadlands Village, The Glen and Kentlands Square I
Notes Payable [Line Items]
Principal and interest payments							306,000
Amortization period							25 years
Debt instrument final payment							28,400,000
Amortization of principal							1,500,000
Number of shopping centers							3
Fixed Rate Mortgage Notes Payable \| 5.76% due May 2019
Notes Payable [Line Items]
Interest rate							5.76%
Fixed Rate Mortgage Notes Payable \| 5.76% due May 2019 \| Olde Forte Village
Notes Payable [Line Items]
Principal and interest payments							98,000
Amortization period							25 years
Debt instrument final payment							9,000,000
Amortization of principal							495,000
Fixed Rate Mortgage Notes Payable \| 5.62% due July 2019
Notes Payable [Line Items]
Interest rate							5.62%
Fixed Rate Mortgage Notes Payable \| 5.62% due July 2019 \| Countryside
Notes Payable [Line Items]
Principal and interest payments							133,000
Amortization period							25 years
Debt instrument final payment							12,300,000
Amortization of principal							682,000
Fixed Rate Mortgage Notes Payable \| 5.79% due September 2019
Notes Payable [Line Items]
Interest rate							5.79%
Fixed Rate Mortgage Notes Payable \| 5.79% due September 2019 \| Briggs Chancy MarketPlace
Notes Payable [Line Items]
Principal and interest payments							133,000
Amortization period							25 years
Debt instrument final payment							12,200,000
Amortization of principal							658,000
Fixed Rate Mortgage Notes Payable \| 5.22% due January 2020
Notes Payable [Line Items]
Interest rate							5.22%
Fixed Rate Mortgage Notes Payable \| 5.22% due January 2020 \| Shops at Monocacy
Notes Payable [Line Items]
Principal and interest payments							112,000
Amortization period							25 years
Debt instrument final payment							10,600,000
Amortization of principal							596,000
Fixed Rate Mortgage Notes Payable \| 5.60% due May 2020
Notes Payable [Line Items]
Interest rate							5.60%
Fixed Rate Mortgage Notes Payable \| 5.60% due May 2020 \| Boca Valley Plaza
Notes Payable [Line Items]
Principal and interest payments							75,000
Amortization period							30 years
Debt instrument final payment							9,100,000
Amortization of principal							278,000
Fixed Rate Mortgage Notes Payable \| 5.30% due June 2020
Notes Payable [Line Items]
Interest rate							5.30%
Fixed Rate Mortgage Notes Payable \| 5.30% due June 2020 \| Palm Springs Center
Notes Payable [Line Items]
Principal and interest payments							75,000
Amortization period							25 years
Debt instrument final payment							7,100,000
Amortization of principal							386,000
Fixed Rate Mortgage Notes Payable \| 5.83% due July 2020
Notes Payable [Line Items]
Interest rate							5.83%
Fixed Rate Mortgage Notes Payable \| 5.83% due July 2020 \| Thruway
Notes Payable [Line Items]
Principal and interest payments							289,000
Amortization period							25 years
Debt instrument final payment							34,800,000
Amortization of principal							1,021,000
Fixed Rate Mortgage Notes Payable \| 5.81% due February 2021
Notes Payable [Line Items]
Interest rate							5.81%
Fixed Rate Mortgage Notes Payable \| 5.81% due February 2021 \| Jamestown Place
Notes Payable [Line Items]
Principal and interest payments							66,000
Amortization period							25 years
Debt instrument final payment							6,100,000
Amortization of principal							303,000
Fixed Rate Mortgage Notes Payable \| 6.01% due August 2021
Notes Payable [Line Items]
Interest rate							6.01%
Fixed Rate Mortgage Notes Payable \| 6.01% due August 2021 \| Hunt Club Corners
Notes Payable [Line Items]
Principal and interest payments							42,000
Amortization period							30 years
Debt instrument final payment							5,000,000
Amortization of principal							133,000
Fixed Rate Mortgage Notes Payable \| 5.62% due June 2022
Notes Payable [Line Items]
Interest rate							5.62%
Fixed Rate Mortgage Notes Payable \| 5.62% due June 2022 \| Landsowne Town Center
Notes Payable [Line Items]
Principal and interest payments							230,000
Amortization period							30 years
Debt instrument final payment							28,200,000
Amortization of principal							759,000
Fixed Rate Mortgage Notes Payable \| 6.08% due September 2022
Notes Payable [Line Items]
Interest rate							6.08%
Fixed Rate Mortgage Notes Payable \| 6.08% due September 2022 \| Orchard Park
Notes Payable [Line Items]
Principal and interest payments							73,000
Amortization period							30 years
Debt instrument final payment							8,600,000
Amortization of principal							212,000
Fixed Rate Mortgage Notes Payable \| 6.43% due April 2023
Notes Payable [Line Items]
Interest rate							6.43%
Fixed Rate Mortgage Notes Payable \| 6.43% due April 2023 \| BJs Wholesale
Notes Payable [Line Items]
Principal and interest payments							80,000
Amortization period							30 years
Debt instrument final payment							9,300,000
Amortization of principal							208,000
Fixed Rate Mortgage Notes Payable \| 6.28% due February 2024
Notes Payable [Line Items]
Interest rate							6.28%
Fixed Rate Mortgage Notes Payable \| 6.28% due February 2024 \| Great Falls Shopping Center
Notes Payable [Line Items]
Principal and interest payments							138,000
Amortization period							26 years
Debt instrument final payment							6,300,000
Amortization of principal							689,000
Number of notes							3
Fixed Rate Mortgage Notes Payable \| 7.35% due June 2024
Notes Payable [Line Items]
Interest rate							7.35%
Fixed Rate Mortgage Notes Payable \| 7.35% due June 2024 \| Leesburg Pike
Notes Payable [Line Items]
Principal and interest payments							135,000
Amortization period							25 years
Debt instrument final payment							11,500,000
Amortization of principal							373,000
Fixed Rate Mortgage Notes Payable \| 7.60% due June 2024
Notes Payable [Line Items]
Interest rate							7.60%
Fixed Rate Mortgage Notes Payable \| 7.60% due June 2024 \| Village Center
Notes Payable [Line Items]
Principal and interest payments							119,000
Amortization period							25 years
Debt instrument final payment							10,100,000
Amortization of principal							314,000
Fixed Rate Mortgage Notes Payable \| 7.02% due July 2024
Notes Payable [Line Items]
Interest rate							7.02%
Fixed Rate Mortgage Notes Payable \| 7.02% due July 2024 \| White Oak Shopping Center
Notes Payable [Line Items]
Principal and interest payments							193,000
Amortization period							24 years 4 months 24 days
Debt instrument final payment							18,500,000
Amortization of principal							514,000
Debt instrument amount											10,500,000
Fixed Rate Mortgage Notes Payable \| 7.45% due July 2024
Notes Payable [Line Items]
Interest rate							7.45%
Fixed Rate Mortgage Notes Payable \| 7.45% due July 2024 \| Avenel Business Park
Notes Payable [Line Items]
Principal and interest payments							246,000
Amortization period							25 years
Debt instrument final payment							20,900,000
Amortization of principal							664,000
Fixed Rate Mortgage Notes Payable \| 7.30% due January 2025
Notes Payable [Line Items]
Interest rate							7.30%
Fixed Rate Mortgage Notes Payable \| 7.30% due January 2025 \| Ashburn Village
Notes Payable [Line Items]
Principal and interest payments							240,000
Amortization period							25 years
Debt instrument final payment							20,500,000
Amortization of principal							641,000
Fixed Rate Mortgage Notes Payable \| 6.18% due January 2026
Notes Payable [Line Items]
Interest rate							6.18%
Fixed Rate Mortgage Notes Payable \| 6.18% due January 2026 \| Ravenwood
Notes Payable [Line Items]
Principal and interest payments							111,000
Amortization period							25 years
Debt instrument final payment							10,100,000
Amortization of principal							352,000
Fixed Rate Mortgage Notes Payable \| 5.31% due April 2026
Notes Payable [Line Items]
Interest rate							5.31%
Fixed Rate Mortgage Notes Payable \| 5.31% due April 2026 \| Clarendon Center
Notes Payable [Line Items]
Principal and interest payments							753,000
Amortization period							25 years
Debt instrument final payment							70,500,000
Amortization of principal							2,800,000
Fixed Rate Mortgage Notes Payable \| 4.30% due October 2026
Notes Payable [Line Items]
Interest rate							4.30%
Fixed Rate Mortgage Notes Payable \| 4.30% due October 2026 \| Severna Park Market Place
Notes Payable [Line Items]
Principal and interest payments							207,000
Amortization period							25 years
Debt instrument final payment							20,300,000
Amortization of principal							950,000
Fixed Rate Mortgage Notes Payable \| 4.53% due November 2026
Notes Payable [Line Items]
Interest rate							4.53%
Fixed Rate Mortgage Notes Payable \| 4.53% due November 2026 \| Kentlands Square II
Notes Payable [Line Items]
Principal and interest payments							240,000
Amortization period							25 years
Debt instrument final payment							23,100,000
Amortization of principal							1,042,000
Fixed Rate Mortgage Notes Payable \| 4.70% due December 2026
Notes Payable [Line Items]
Interest rate							4.70%
Fixed Rate Mortgage Notes Payable \| 4.70% due December 2026 \| Cranberry Square
Notes Payable [Line Items]
Principal and interest payments							113,000
Amortization period							25 years
Debt instrument final payment							10,900,000
Amortization of principal							473,000
Fixed Rate Mortgage Notes Payable \| 5.84% due May 2027
Notes Payable [Line Items]
Interest rate							5.84%
Fixed Rate Mortgage Notes Payable \| 5.84% due May 2027 \| Seven Corners
Notes Payable [Line Items]
Principal and interest payments			463,200				463,200
Amortization period							25 years
Debt instrument final payment			42,300,000				42,300,000
Amortization of principal							1,500,000
Debt instrument amount							73,000,000
Fixed Rate Mortgage Notes Payable \| 4.04% due April 2028
Notes Payable [Line Items]
Interest rate							4.04%
Fixed Rate Mortgage Notes Payable \| 4.04% due April 2028 \| Hampshire Langley
Notes Payable [Line Items]
Principal and interest payments							95,400
Amortization period							25 years
Debt instrument final payment							9,500,000
Amortization of principal							437,000
Fixed Rate Mortgage Notes Payable \| 3.51% due June 2028
Notes Payable [Line Items]
Interest rate							3.51%
Fixed Rate Mortgage Notes Payable \| 3.51% due June 2028 \| Beacon Center
Notes Payable [Line Items]
Principal and interest payments							203,200
Amortization period							20 years
Debt instrument final payment							11,400,000
Amortization of principal							1,251,000
Fixed Rate Mortgage Notes Payable \| 3.99% due September 2028
Notes Payable [Line Items]
Interest rate							3.99%
Fixed Rate Mortgage Notes Payable \| 3.99% due September 2028 \| Seabreeze Plaza
Notes Payable [Line Items]
Principal and interest payments							94,900		94,900
Amortization period							25 years		25 years
Debt instrument final payment							9,500,000		9,500,000
Amortization of principal							433,000
Fixed Rate Mortgage Notes Payable \| 4.88% due September 2032
Notes Payable [Line Items]
Interest rate							4.88%
Fixed Rate Mortgage Notes Payable \| 4.88% due September 2032 \| Park Van Ness
Notes Payable [Line Items]
Principal and interest payments							413,500
Amortization period							25 years
Debt instrument final payment							39,600,000
Debt instrument amount						71,580,000	71,580,000
Fixed Rate Mortgage Notes Payable \| 8.00% due April 2034
Notes Payable [Line Items]
Interest rate							8.00%
Fixed Rate Mortgage Notes Payable \| 8.00% due April 2034 \| Olney
Notes Payable [Line Items]
Principal and interest payments							60,400
Debt instrument final payment							14,700,000
Amortization of principal							119,000
Fixed rate increase on note							1.50%
Interest rate							8.00%
Variable Rate Loans Payable
Notes Payable [Line Items]
Interest rate spread on LIBOR							1.53%
Variable Rate Loans Payable \| Revolving credit facility
Notes Payable [Line Items]
Line of credit facility, maximum borrowing capacity							275,000,000
Interest rate spread on LIBOR							1.45%
Debt maturity extension period							1 year
Debt instrument fee							0.15%
Debt instrument frequency of periodic payment							Monthly
Variable Rate Loans Payable \| Revolving credit facility \| One-month LIBOR
Notes Payable [Line Items]
Interest rate spread on LIBOR							1.45%
Variable Rate Loans Payable \| Northrock loan
Notes Payable [Line Items]
Interest rate spread on LIBOR							1.65%
Variable Rate Loans Payable \| Northrock loan \| Northrock
Notes Payable [Line Items]
Principal and interest payments							47,000
Debt instrument final payment							14,200,000
Amortization of principal							277,000
Variable Rate Loans Payable \| Metro Pike Center bank loan
Notes Payable [Line Items]
Interest rate spread on LIBOR							1.65%
Variable Rate Loans Payable \| Metro Pike Center bank loan \| Metro Pike Center
Notes Payable [Line Items]
Principal and interest payments							48,000
Debt instrument final payment							14,800,000
Amortization of principal							$288,000

[1]	Interest rate and scheduled maturity data presented as of DecemberB 31, 2014. Totals computed using weighted averages.

Mortgage_Notes_Payable_Revolvi5

Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs - Scheduled Maturities of All Debt, Including Scheduled Principal Amortization (Detail) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Balloon Payments
2015	$14,885
2016	28,879
2017	0
2018	70,748	[1]
2019	60,794
Thereafter	426,652
Balloon Payments	601,958
Outstanding line of credit	43,000		0
Scheduled Principal Amortization
2015	23,192
2016	23,496
2017	24,679
2018	24,822
2019	23,489
Thereafter	135,752
Scheduled Principal Amortization	255,430
Total
2015	38,077
2016	52,375
2017	24,679
2018	95,570
2019	84,283
Thereafter	562,404
Total	$857,388		$820,100

[1]	Includes $43.0B million outstanding under the line of credit.

Mortgage_Notes_Payable_Revolvi6

Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs - Interest Expense and Amortization of Deferred Debt Costs (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Disclosure [Abstract]
Interest incurred	$45,396,000	$45,502,000	$48,010,000
Amortization of deferred debt costs	1,327,000	1,257,000	1,576,000
Capitalized interest	-689,000	-170,000	-42,300
Total	$46,034,000	$46,589,000	$49,544,000

Lease_Agreements_Additional_In

Lease Agreements - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Leases [Abstract]
Base rent (including straight-line rent)	$164,599	$159,898	$152,777
Expense recoveries	32,132	30,949	30,391
Percentage rent	$1,492	$1,575	$1,545

Lease_Agreements_Future_Contra

Lease Agreements - Future Contractual Payments Under Noncancelable Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified	Dec. 31, 2014
Leases [Abstract]
2015	$152,661
2016	135,703
2017	116,025
2018	96,439
2019	73,626
Thereafter	275,551
Total future contractual payments	$850,005

Long_Term_Lease_Obligations_Ad

Long Term Lease Obligations - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Leases Disclosure [Line Items]
Minimum rental obligations	$176,000	$176,000	$176,000
Lease extension period			5 years
Percentage of annual increase in base rent			3.00%
Rent expense	840,800	850,600	850,000
90-year Ground Leasehold Interest
Leases Disclosure [Line Items]
Ground leasehold interest period	90 years
Minimum annual lease rent over lease term	1
99-year Ground Lease
Leases Disclosure [Line Items]
Ground leasehold interest period	99 years
Minimum annual lease rent over lease term	$1
Percent of underlying land held under a 99-year ground lease	3.40%
Flagship Center
Leases Disclosure [Line Items]
Number of developed parcels	2
Minimum
Leases Disclosure [Line Items]
Lease expiration year	2058
Maximum
Leases Disclosure [Line Items]
Lease expiration year	2068

LongTerm_Lease_Obligations_Fut

Long-Term Lease Obligations - Future Minimum Rental Commitments Under Ground Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified	Dec. 31, 2014
Leases Future Minimum Payments [Line Items]
2015	$176
2016	176
2017	176
2018	176
2019	177
Thereafter	9,186
Total	10,067
Beacon Center
Leases Future Minimum Payments [Line Items]
2015	60
2016	60
2017	60
2018	60
2019	60
Thereafter	2,541
Total	2,841
Olney
Leases Future Minimum Payments [Line Items]
2015	56
2016	56
2017	56
2018	56
2019	57
Thereafter	3,760
Total	4,041
Southdale
Leases Future Minimum Payments [Line Items]
2015	60
2016	60
2017	60
2018	60
2019	60
Thereafter	2,885
Total	$3,185

Stockholders_Equity_and_Noncon1

Stockholders' Equity and Noncontrolling Interest - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended			0 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013	Nov. 30, 2003	Mar. 31, 2008	Nov. 12, 2014	Feb. 12, 2013
Class of Stock [Line Items]
Income attributable to noncontrolling interests	$11,045	$3,970	$6,406
Series A Preferred Stock
Class of Stock [Line Items]
Number of depositary shares sold					4,000,000
Depository shares to cumulative redeemable preferred stock ratio					0.01
Dividend rate on preferred stock					8.00%
Depositary shares, redeemable price (in usd per share)					$25
Annual dividend on depositary shares					$2
Cumulative redeemable preferred stock liquidation preference					$25
Percentage of redeemable preferred stock				60.00%
Series B Preferred Stock
Class of Stock [Line Items]
Number of depositary shares sold						3,173,115
Depository shares to cumulative redeemable preferred stock ratio						0.01
Dividend rate on preferred stock						9.00%
Depositary shares, redeemable price (in usd per share)						$25
Annual dividend on depositary shares						$2.25
Cumulative redeemable preferred stock liquidation preference						$25
Series B Preferred Stock \| Minimum
Class of Stock [Line Items]
Depository shares redemption date						15-Mar-13
Series C Preferred Stock
Class of Stock [Line Items]
Number of depositary shares sold							1,600,000	5,600,000
Depository shares to cumulative redeemable preferred stock ratio								0.01
Dividend rate on preferred stock								6.88%
Annual dividend on depositary shares								$1.72
Cumulative redeemable preferred stock liquidation preference								$25
Percentage of redeemable preferred stock								6.88%
Series C preferred stock	$39,260	$135,221	$0				$39,260	$135,200
Dividends payment date								15-Apr-13
Series C Preferred Stock \| Minimum
Class of Stock [Line Items]
Depository shares redemption date								12-Feb-18
Dividends record date								12-Feb-13
Series C Preferred Stock \| Maximum
Class of Stock [Line Items]
Dividends record date								31-Mar-13

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 04, 2012
Related Party Transactions [Abstract]
Company contribution to a multi employer 401K plan at discretionary amount of employee's cash compensation, maximum percentage	6.00%
Company contribution to a multi employer 401K plan at discretionary amount of employee's cash compensation, amount	$379,000	$369,000	$379,000
Deferred compensation, employee contribution, percentage	2.00%
Deferred compensation, employer contribution, percentage	3	3	3
Deferred compensation, company contribution, amount	192,800	191,300	238,000
Deferred compensation, cumulative unfunded liability	1,800,000	1,600,000
Ancillary costs and expenses	7,400,000	6,300,000	6,000,000
Liability due to The Saul Organization for the Company's share of these ancillary costs and expenses	543,000	499,000
Insurance commissions and fees expense	427,300	447,300	372,000
Monthly consulting fees				60,000
Consulting fees	$495,000	$720,000	$225,000

Stock_Option_Plan_Additional_I

Stock Option Plan - Additional Information (Detail) (USD $)

12 Months Ended

0 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

6-May-05

1-May-06

Apr. 27, 2007

Apr. 25, 2008

Apr. 24, 2009

7-May-10

13-May-11

4-May-12

10-May-13

9-May-14

Dec. 31, 1993

Dec. 31, 2004

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Exercise price of options (in usd per share)

$47.03

$44.42

$39.29

Fair value stock option grant

$9,596,150

the 1993 Plan | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Authorized shares for a grant

400,000

Amended 2004 Plan | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Authorized shares for a grant

2,000,000

Amended 2004 Plan | Stock Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Authorized shares for a grant

200,000

2005 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

5-May-15

Exercise price of options (in usd per share)

$33.22

Fair value stock option grant

484,500

2005 Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Options vested (in percent)

25.00%

Fair value stock option grant

413,400

2005 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Fair value stock option grant

71,100

2005 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

162,500

2005 Options | Stock Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Option vesting period

4 years

2005 Options | Incentive Stock Option

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

35,500

2005 Options | Nonqualified Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

127,000

2006 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

30-Apr-16

Exercise price of options (in usd per share)

$40.35

Fair value stock option grant

143,400

2006 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

2006 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

30,000

2007 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

26-Apr-17

Exercise price of options (in usd per share)

$54.17

Fair value stock option grant

1,500,000

2007 Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Options vested (in percent)

25.00%

Fair value stock option grant

1,300,000

2007 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Fair value stock option grant

285,300

2007 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

165,000

2007 Options | Stock Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Option vesting period

4 years

2007 Options | Incentive Stock Option

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

27,560

2007 Options | Nonqualified Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

137,440

2008 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

24-Apr-18

Exercise price of options (in usd per share)

$50.15

Fair value stock option grant

254,700

2008 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

2008 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

30,000

2009 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

23-Apr-19

Exercise price of options (in usd per share)

$32.68

Fair value stock option grant

222,950

2009 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

2009 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

32,500

2010 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

6-May-20

Exercise price of options (in usd per share)

$38.76

Fair value stock option grant

287,950

2010 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

2010 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

32,500

2011 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

12-May-21

Exercise price of options (in usd per share)

$41.82

Fair value stock option grant

1,600,000

2011 Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Options vested (in percent)

25.00%

Fair value stock option grant

1,300,000

2011 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Fair value stock option grant

297,375

2011 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

195,000

2011 Options | Stock Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Option vesting period

4 years

2011 Options | Incentive Stock Option

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

65,300

2011 Options | Nonqualified Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

129,700

2012 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

3-May-22

Exercise price of options (in usd per share)

$39.29

Fair value stock option grant

1,700,000

2012 Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Options vested (in percent)

25.00%

Fair value stock option grant

1,400,000

2012 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Fair value stock option grant

257,250

2012 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

277,500

2012 Options | Incentive Stock Option

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

26,157

2012 Options | Nonqualified Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

251,343

2013 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Plan expiration date

9-May-23

Exercise price of options (in usd per share)

$44.42

Fair value stock option grant

1,500,000

2013 Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options vested (in percent)

25.00%

Fair value stock option grant

1,300,000

2013 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Fair value stock option grant

300,000

2013 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

237,500

2013 Options | Stock Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Option vesting period

4 years

2013 Options | Incentive Stock Option

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

35,592

2013 Options | Nonqualified Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

201,908

2014 Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Plan expiration date

8-May-24

Exercise price of options (in usd per share)

47.03

Fair value stock option grant

1,300,000

2014 Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Options vested (in percent)

25.00%

Fair value stock option grant

1,200,000

2014 Options | Director

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Number of individuals granted options

Fair value stock option grant

109,500

2014 Options | Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

200,000

2014 Options | Stock Options | Officer

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Option vesting period

4 years

2014 Options | Incentive Stock Option

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

29,300

2014 Options | Nonqualified Stock Options

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Options granted to purchase stocks (in shares)

170,700

Stock_Option_Plan_Stock_Option

Stock Option Plan - Stock Options Issued (Detail) (USD $)	12 Months Ended
Stock Option Plan - Stock Options Issued (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grant (in shares)	1,362,500
Vested (in shares)	716,250
Exercised (in shares)	301,792
Forfeited (in shares)	312,500
Exercisable at December 31 (in shares)	380,708	413,000	377,715
Remaining unexercised (in shares)	748,208
Exercise price (in usd per share)	$37.71	$33.15	$31.03
Total value at grant date	$9,596,150
Estimated forfeitures	1,823,557
Expensed in previous years	3,404,622
Future expense	1,891,071
Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	632,365
Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	879,710
Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	964,825
Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	112,900	124,400	110,000
Directors \| 5/6/2005
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	6-May-05
Total grant (in shares)	30,000
Vested (in shares)	30,000
Exercised (in shares)	22,500
Forfeited (in shares)	0
Exercisable at December 31 (in shares)	7,500
Remaining unexercised (in shares)	7,500
Exercise price (in usd per share)	$33.22
Volatility	0.198
Expected life (years)	10 years
Assumed yield	6.91%
Risk-free rate	4.28%
Total value at grant date	71,100
Expensed in previous years	71,100
Future expense	0
Directors \| 5/6/2005 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/6/2005 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/6/2005 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/1/2006
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	1-May-06
Total grant (in shares)	30,000
Vested (in shares)	30,000
Exercised (in shares)	10,000
Forfeited (in shares)	2,500
Exercisable at December 31 (in shares)	17,500
Remaining unexercised (in shares)	17,500
Exercise price (in usd per share)	$40.35
Volatility	0.206
Expected life (years)	9 years
Assumed yield	5.93%
Risk-free rate	5.11%
Total value at grant date	143,400
Expensed in previous years	143,400
Future expense	0
Directors \| 5/1/2006 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/1/2006 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/1/2006 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/27/2007
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	27-Apr-07
Total grant (in shares)	30,000
Vested (in shares)	30,000
Exercised (in shares)	0
Forfeited (in shares)	7,500
Exercisable at December 31 (in shares)	22,500
Remaining unexercised (in shares)	22,500
Exercise price (in usd per share)	$54.17
Volatility	0.225
Expected life (years)	8 years
Assumed yield	4.39%
Risk-free rate	4.65%
Total value at grant date	285,300
Expensed in previous years	285,300
Future expense	0
Directors \| 4/27/2007 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/27/2007 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/27/2007 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/25/2008
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	25-Apr-08
Total grant (in shares)	30,000
Vested (in shares)	30,000
Exercised (in shares)	0
Forfeited (in shares)	7,500
Exercisable at December 31 (in shares)	22,500
Remaining unexercised (in shares)	22,500
Exercise price (in usd per share)	$50.15
Volatility	0.237
Expected life (years)	7 years
Assumed yield	4.09%
Risk-free rate	3.49%
Total value at grant date	254,700
Expensed in previous years	254,700
Future expense	0
Directors \| 4/25/2008 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/25/2008 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/25/2008 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/24/2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	24-Apr-09
Total grant (in shares)	32,500
Vested (in shares)	32,500
Exercised (in shares)	20,000
Forfeited (in shares)	0
Exercisable at December 31 (in shares)	12,500
Remaining unexercised (in shares)	12,500
Exercise price (in usd per share)	$32.68
Volatility	0.344
Expected life (years)	6 years
Assumed yield	4.54%
Risk-free rate	2.19%
Total value at grant date	222,950
Expensed in previous years	222,950
Future expense	0
Directors \| 4/24/2009 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/24/2009 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 4/24/2009 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/7/2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	7-May-10
Total grant (in shares)	32,500
Vested (in shares)	32,500
Exercised (in shares)	10,000
Forfeited (in shares)	2,500
Exercisable at December 31 (in shares)	20,000
Remaining unexercised (in shares)	20,000
Exercise price (in usd per share)	$38.76
Volatility	0.369
Expected life (years)	5 years
Assumed yield	4.23%
Risk-free rate	2.17%
Total value at grant date	287,950
Expensed in previous years	287,950
Future expense	0
Directors \| 5/7/2010 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/7/2010 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/7/2010 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/13/2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	13-May-11
Total grant (in shares)	32,500
Vested (in shares)	32,500
Exercised (in shares)	10,000
Forfeited (in shares)	2,500
Exercisable at December 31 (in shares)	20,000
Remaining unexercised (in shares)	20,000
Exercise price (in usd per share)	$41.82
Volatility	0.358
Expected life (years)	5 years
Assumed yield	4.16%
Risk-free rate	1.86%
Total value at grant date	297,375
Expensed in previous years	297,375
Future expense	0
Directors \| 5/13/2011 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/13/2011 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/13/2011 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/4/2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	4-May-12
Total grant (in shares)	35,000
Vested (in shares)	35,000
Exercised (in shares)	10,000
Forfeited (in shares)	0
Exercisable at December 31 (in shares)	25,000
Remaining unexercised (in shares)	25,000
Exercise price (in usd per share)	$39.29
Volatility	0.348
Expected life (years)	5 years
Assumed yield	4.61%
Risk-free rate	0.78%
Total value at grant date	257,250
Expensed in previous years	0
Future expense	0
Directors \| 5/4/2012 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	257,250
Directors \| 5/4/2012 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/4/2012 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/10/2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	10-May-13
Total grant (in shares)	35,000
Vested (in shares)	35,000
Exercised (in shares)	7,500
Forfeited (in shares)	0
Exercisable at December 31 (in shares)	27,500
Remaining unexercised (in shares)	27,500
Exercise price (in usd per share)	$44.42
Volatility	0.333
Expected life (years)	5 years
Assumed yield	4.53%
Risk-free rate	0.82%
Total value at grant date	278,250
Expensed in previous years	0
Future expense	0
Directors \| 5/10/2013 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/10/2013 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	278,250
Directors \| 5/10/2013 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/9/2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	9-May-14
Total grant (in shares)	30,000
Vested (in shares)	30,000
Exercised (in shares)	0
Forfeited (in shares)	0
Exercisable at December 31 (in shares)	30,000
Remaining unexercised (in shares)	30,000
Exercise price (in usd per share)	$47.03
Volatility	0.173
Expected life (years)	5 years
Assumed yield	4.48%
Risk-free rate	1.63%
Total value at grant date	109,500
Expensed in previous years	0
Future expense	0
Directors \| 5/9/2014 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/9/2014 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Directors \| 5/9/2014 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	109,500
Directors \| Subtotals
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grant (in shares)	317,500
Vested (in shares)	317,500
Exercised (in shares)	90,000
Forfeited (in shares)	22,500
Exercisable at December 31 (in shares)	205,000
Remaining unexercised (in shares)	205,000
Total value at grant date	2,207,775
Expensed in previous years	1,562,775
Future expense	0
Directors \| Subtotals \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	257,250
Directors \| Subtotals \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	278,250
Directors \| Subtotals \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	109,500
Officers \| 5/6/2005
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	6-May-05
Total grant (in shares)	132,500
Vested (in shares)	118,750
Exercised (in shares)	115,750
Forfeited (in shares)	13,750
Exercisable at December 31 (in shares)	3,000
Remaining unexercised (in shares)	3,000
Exercise price (in usd per share)	$33.22
Volatility	0.207
Expected life (years)	8 years
Assumed yield	6.37%
Risk-free rate	4.15%
Total value at grant date	413,400
Estimated forfeitures	35,100
Expensed in previous years	378,300
Future expense	0
Officers \| 5/6/2005 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Officers \| 4/27/2007
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	27-Apr-07
Total grant (in shares)	135,000
Vested (in shares)	67,500
Exercised (in shares)	3,528
Forfeited (in shares)	67,500
Exercisable at December 31 (in shares)	63,972
Remaining unexercised (in shares)	63,972
Exercise price (in usd per share)	$54.17
Volatility	0.233
Expected life (years)	6 years 6 months
Assumed yield	4.13%
Risk-free rate	4.61%
Total value at grant date	1,339,200
Estimated forfeitures	62,000
Expensed in previous years	1,277,200
Future expense	0
Weighted average term of remaining future expense	2 years 8 months 3 days
Officers \| 4/27/2007 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Officers \| 4/27/2007 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Officers \| 4/27/2007 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Officers \| 5/13/2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	13-May-11
Total grant (in shares)	162,500
Vested (in shares)	105,625
Exercised (in shares)	46,889
Forfeited (in shares)	43,750
Exercisable at December 31 (in shares)	47,486
Remaining unexercised (in shares)	71,861
Exercise price (in usd per share)	$41.82
Volatility	0.33
Expected life (years)	8 years
Assumed yield	4.81%
Risk-free rate	2.75%
Total value at grant date	1,366,625
Estimated forfeitures	387,550
Expensed in previous years	186,347
Future expense	69,512
Officers \| 5/13/2011 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	270,391
Officers \| 5/13/2011 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	235,350
Officers \| 5/13/2011 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	217,475
Officers \| 5/4/2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	4-May-12
Total grant (in shares)	242,500
Vested (in shares)	56,250
Exercised (in shares)	30,000
Forfeited (in shares)	135,000
Exercisable at December 31 (in shares)	26,250
Remaining unexercised (in shares)	77,500
Exercise price (in usd per share)	$39.29
Volatility	0.315
Expected life (years)	8 years
Assumed yield	5.28%
Risk-free rate	1.49%
Total value at grant date	1,518,050
Estimated forfeitures	889,690
Expensed in previous years	0
Future expense	209,461
Officers \| 5/4/2012 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	104,724
Officers \| 5/4/2012 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	157,083
Officers \| 5/4/2012 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	157,092
Officers \| 5/10/2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	10-May-13
Total grant (in shares)	202,500
Vested (in shares)	50,625
Exercised (in shares)	15,625
Forfeited (in shares)	30,000
Exercisable at December 31 (in shares)	35,000
Remaining unexercised (in shares)	156,875
Exercise price (in usd per share)	$44.42
Volatility	0.304
Expected life (years)	8 years
Assumed yield	5.12%
Risk-free rate	1.49%
Total value at grant date	1,401,300
Estimated forfeitures	280,468
Expensed in previous years	0
Future expense	627,895
Officers \| 5/10/2013 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Officers \| 5/10/2013 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	209,027
Officers \| 5/10/2013 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	283,910
Officers \| 5/9/2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date	9-May-14
Total grant (in shares)	170,000
Vested (in shares)	0
Exercised (in shares)	0
Forfeited (in shares)	0
Exercisable at December 31 (in shares)	0
Remaining unexercised (in shares)	170,000
Exercise price (in usd per share)	$47.03
Volatility	0.306
Expected life (years)	7 years
Assumed yield	4.89%
Risk-free rate	2.17%
Total value at grant date	1,349,800
Estimated forfeitures	168,749
Expensed in previous years	0
Future expense	984,203
Officers \| 5/9/2014 \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Officers \| 5/9/2014 \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	0
Officers \| 5/9/2014 \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	196,848
Officers \| Subtotals
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grant (in shares)	1,045,000
Vested (in shares)	398,750
Exercised (in shares)	211,792
Forfeited (in shares)	290,000
Exercisable at December 31 (in shares)	175,708
Remaining unexercised (in shares)	543,208
Total value at grant date	7,388,375
Estimated forfeitures	1,823,557
Expensed in previous years	1,841,847
Future expense	1,891,071
Officers \| Subtotals \| Expensed in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	375,115
Officers \| Subtotals \| Expensed in 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	601,460
Officers \| Subtotals \| Expensed in 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation	$855,325

Stock_Option_Plan_Summary_of_O

Stock Option Plan - Summary of Option Activity (Detail) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Shares
Outstanding at January 1 (in shares)	753,625	570,840	674,585
Granted (in shares)	200,000	237,500	277,500
Exercised (in shares)	-167,917	-49,715	-149,995
Expired/Forfeited (in shares)	-37,500	-5,000	-231,250
Outstanding December 31 (in shares)	748,208	753,625	570,840
Exercisable at December 31 (in shares)	380,708	413,000	377,715
Weighted Average Exercise Price
Outstanding at January 1 (in usd per share)	$42.55	$41.04	$40.40
Granted (in usd per share)	$47.03	$44.42	$39.29
Exercised (in usd per share)	$37.71	$33.15	$31.03
Expired/Forfeited (in usd per share)	$43.56	$52.16	$43.56
Outstanding December 31 (in usd per share)	$44.79	$42.55	$41.04
Exercisable at December 31 (in usd per share)	$44.85	$42.42	$41.41
Intrinsic value of options exercised	$2	$0.60	$1.60
Intrinsic value of options outstanding	9.3
Intrinsic value of options exercisable	$4.70
Closing price (in usd per share)	$57.19
Weighted average remaining life of options exercisable	5 years 5 months 8 days
Weighted average remaining life of options outstanding	6 years 11 months 15 days

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value of Financial Instruments [Line Items]
Interest rate	3.65%	4.85%
Notes payable, fair value	$886.40	$828.70
Notes payable, carrying value	784.8	789.9
Interest Rate Swap
Fair Value of Financial Instruments [Line Items]
Interest rate swap agreement, termination date	1-Jul-20
Fair value of derivative liability	$3.20

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Changes in Fair Value of Swaps (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Increase (decrease) in fair value:
Recognized in earnings	($10)	($7)	$36
Recognized in other comprehensive income	-675	2,897	-932
Total	($685)	$2,890	($896)

Distributions_Additional_Infor

Distributions - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended			0 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 30, 2015	Jan. 15, 2015	Jan. 07, 2015
Dividends [Line Items]
Common stock issued, discount rate		3.00%
Common stock distributions (in usd per share)		$1.56	$1.44	$1.44
Dividends declared per common share outstanding (in usd per share)	$0.40
Distribution to limited partnership unitholders		$11,117	$9,956	$9,955
Subsequent Event
Dividends [Line Items]
Common stock dividend paid					8,400
Distribution to limited partnership unitholders					2,900
Distribution to limited partnership unitholders (in usd per share)					$0.40
Dividend Income
Dividends [Line Items]
Common stock distributions (in usd per share)		$1.56	$0.96	$0.95
Return on Invested Capital
Dividends [Line Items]
Common stock distributions (in usd per share)			$0.48	$0.49
Series A Preferred Stock
Dividends [Line Items]
Preferred stock dividend (in usd per share)		$2.41	$2	$2
Series B Preferred Stock
Dividends [Line Items]
Preferred stock dividend (in usd per share)			$0.99	$2.25
Series C Preferred Stock
Dividends [Line Items]
Preferred stock dividend (in usd per share)		$1.72	$1.09
Series C Preferred Stock \| Subsequent Event
Dividends [Line Items]
Dividends declared per preferred share outstanding (in usd per share)							$0.43
Preferred stock distributions						$3,100
Common Stock
Dividends [Line Items]
Dividends record date	16-Jan-15

Distributions_Summary_of_Distr

Distributions - Summary of Distributions Paid Including Activity in Plan as well as Limited Partnership Units Issued from Reinvestment of Unit Distributions (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Dividends [Line Items]
Preferred Stockholders	$13,474	$14,561	$15,140
Common Stockholders	32,346	29,205	28,135
Limited Partnership Unitholders	11,117	9,956	9,956
Dividend Reinvestments, Common Stock Issued (in shares)	197,638	475,162	595,388
Dividend Reinvestments, Limited Partnership Units Issued (in shares)	196,183	88,309
31-Oct
Dividends [Line Items]
Preferred Stockholders	3,856	3,206	3,785
Common Stockholders	8,348	7,388	7,120
Limited Partnership Unitholders	2,879	2,489	2,489
Dividend Reinvestments, Common Stock Issued (in shares)	40,142	48,836	141,960
Dividend Reinvestments, Discounted Share Price (in usd per share)	$52.71	$46.27	$42.23
Dividend Reinvestments, Limited Partnership Units Issued (in shares)		88,309
Dividend Reinvestments, Average Unit Price (in usd per share)		$46.93
31-Jul
Dividends [Line Items]
Preferred Stockholders	3,206	3,206	3,785
Common Stockholders	8,314	7,327	7,063
Limited Partnership Unitholders	2,879	2,489	2,489
Dividend Reinvestments, Common Stock Issued (in shares)	57,696	138,019	144,881
Dividend Reinvestments, Discounted Share Price (in usd per share)	$46.79	$45.21	$40.43
Dividend Reinvestments, Limited Partnership Units Issued (in shares)
30-Apr
Dividends [Line Items]
Preferred Stockholders	3,206	4,364	3,785
Common Stockholders	8,269	7,272	7,005
Limited Partnership Unitholders	2,838	2,489	2,489
Dividend Reinvestments, Common Stock Issued (in shares)	60,212	142,839	145,118
Dividend Reinvestments, Discounted Share Price (in usd per share)	$44.14	$42.85	$38.93
Dividend Reinvestments, Limited Partnership Units Issued (in shares)	104,831
Dividend Reinvestments, Average Unit Price (in usd per share)	$44.77
31-Jan
Dividends [Line Items]
Preferred Stockholders	3,206	3,785	3,785
Common Stockholders	7,415	7,218	6,947
Limited Partnership Unitholders	$2,521	$2,489	$2,489
Dividend Reinvestments, Common Stock Issued (in shares)	39,588	145,468	163,429
Dividend Reinvestments, Discounted Share Price (in usd per share)	$45.15	$41.67	$34.44
Dividend Reinvestments, Limited Partnership Units Issued (in shares)	91,352
Dividend Reinvestments, Average Unit Price (in usd per share)	$45.80

Interim_Results_Unaudited_Summ

Interim Results (Unaudited) - Summary of Results of Operations for Quarterly Periods (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Revenue	$51,264	$50,595	$52,286	$52,947	$50,146	$49,756	$48,809	$49,186	$207,092	$197,897	$190,092
Operating income before loss on early extinguishment of debt, gain on casualty settlement, and noncontrolling interests	12,314	12,479	14,423	12,713	12,211	11,959	7,711	3,388	51,929	35,269	35,096
Gain on sales of properties	0	0	6,069	0					0	0	4,510
Net income attributable to Saul Centers, Inc.	10,496	10,106	16,054	10,287	9,896	9,398	6,594	4,984	46,943	30,872	33,374
Net income (loss) available to common shareholders.	$5,274	$6,900	$12,847	$7,081	$6,690	$6,192	$3,387	($4,608)	$32,102	$11,661	$18,234
Net income (loss) available to common shareholders per diluted share (in dollars per share)	$0.25	$0.33	$0.62	$0.34	$0.33	$0.30	$0.17	($0.23)	$1.54	$0.57	$0.93

Business_Segments_Additional_I

Business Segments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Segment
Segment Reporting [Abstract]
Number of reportable business segments	2

Business_Segments_Detail

Business Segments (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenue	$51,264	$50,595	$52,286	$52,947	$50,146	$49,756	$48,809	$49,186	$207,092	$197,897	$190,092
Expenses									-49,513	-47,942	-47,270
Income from real estate									157,579	149,955	142,822
Interest expense and amortization of deferred debt costs									-46,034	-46,589	-49,544
General and administrative									-16,961	-14,951	-14,274
Subtotal									94,584	88,415	79,004
Depreciation and amortization of deferred leasing costs									-41,203	-49,130	-40,112
Acquisition related costs									-949	-106	-1,129
Predevelopment expenses									-503	-3,910	-2,667
Change in fair value of derivatives									-10	-7	36
Gain on sale of property									6,069	0	0
Gains on sales of properties	0	0	6,069	0					0	0	4,510
Loss on early extinguishment of debt									0	-497	0
Gain on casualty settlement									0	77	219
Loss from operations of property sold									0	0	-81
Net Income									57,988	34,842	39,780
Capital investment									90,268	26,439	54,643
Total assets	1,266,987				1,198,675				1,266,987	1,198,675	1,207,309
Shopping Centers
Segment Reporting Information [Line Items]
Revenue									154,385	145,219	137,647
Expenses									-33,781	-30,729	-30,139
Income from real estate									120,604	114,490	107,508
Interest expense and amortization of deferred debt costs									0	0	0
General and administrative									0	0	0
Subtotal									120,604	114,490	107,508
Depreciation and amortization of deferred leasing costs									-28,082	-27,340	-25,667
Acquisition related costs									-949	-106	-1,129
Predevelopment expenses									0	0	0
Change in fair value of derivatives									0	0	0
Gain on sale of property									6,069
Gains on sales of properties											4,510
Loss on early extinguishment of debt										0
Gain on casualty settlement										77	219
Loss from operations of property sold											-81
Net Income									97,642	87,121	85,360
Capital investment									66,508	18,232	46,353
Total assets	946,819				888,109				946,819	888,109	894,027
Mixed-Use Properties
Segment Reporting Information [Line Items]
Revenue									52,632	52,609	52,309
Expenses									-15,732	-17,213	-17,131
Income from real estate									36,900	35,396	35,178
Interest expense and amortization of deferred debt costs									0	0	0
General and administrative									0	0	0
Subtotal									36,900	35,396	35,178
Depreciation and amortization of deferred leasing costs									-13,121	-21,790	-14,445
Acquisition related costs									0	0	0
Predevelopment expenses									-503	-3,910	-2,667
Change in fair value of derivatives									0	0	0
Gain on sale of property									0
Gains on sales of properties											0
Loss on early extinguishment of debt										0
Gain on casualty settlement										0	0
Loss from operations of property sold											0
Net Income									23,276	9,696	18,066
Capital investment									23,760	8,207	8,290
Total assets	307,901				293,512				307,901	293,512	301,355
Corporate and Other
Segment Reporting Information [Line Items]
Revenue									75	69	136
Expenses									0	0	0
Income from real estate									75	69	136
Interest expense and amortization of deferred debt costs									-46,034	-46,589	-49,544
General and administrative									-16,961	-14,951	-14,274
Subtotal									-62,920	-61,471	-63,682
Depreciation and amortization of deferred leasing costs									0	0	0
Acquisition related costs									0	0	0
Predevelopment expenses									0	0	0
Change in fair value of derivatives									-10	-7	36
Gain on sale of property									0
Gains on sales of properties											0
Loss on early extinguishment of debt										-497
Gain on casualty settlement										0	0
Loss from operations of property sold											0
Net Income									-62,930	-61,975	-63,646
Capital investment									0	0	0
Total assets	$12,267				$17,054				$12,267	$17,054	$11,927

Real_Estate_and_Accumulated_De1

Real Estate and Accumulated Depreciation (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Real Estate Properties [Line Items]
Initial Basis	$805,178
Cost Capitalized Subsequent to Acquisition	730,226
Basis at Close of Period, Land	423,052
Basis at Close of Period, Building and Improvements	1,135,286
Basis at Close of Period, Leasehold Interests	1,821
Total	1,560,159		1,459,439	1,466,068	1,417,845
Accumulated Depreciation	396,617		364,663	353,305	326,397
Book Value	1,163,542		1,094,776
Related Debt	808,997		820,068
Development Land, Related Debt	5,391		0
Total, Related Debt	814,388
Shopping Centers
Real Estate Properties [Line Items]
Initial Basis	750,377
Cost Capitalized Subsequent to Acquisition	394,340
Basis at Close of Period, Land	384,569
Basis at Close of Period, Building and Improvements	758,327
Basis at Close of Period, Leasehold Interests	1,821
Total	1,144,717
Accumulated Depreciation	270,400
Book Value	874,317
Related Debt	631,228
Shopping Centers \| Ashburn Village, Ashburn, VA
Real Estate Properties [Line Items]
Initial Basis	11,431
Cost Capitalized Subsequent to Acquisition	19,492
Basis at Close of Period, Land	6,764
Basis at Close of Period, Building and Improvements	24,159
Basis at Close of Period, Leasehold Interests	0
Total	30,923
Accumulated Depreciation	10,868
Book Value	20,055
Related Debt	30,253
Date Acquired	1994-03
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Ashburn Village, Ashburn, VA \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1994
Shopping Centers \| Ashburn Village, Ashburn, VA \| Construction One \| Minimum
Real Estate Properties [Line Items]
Date of Construction	2000
Shopping Centers \| Ashburn Village, Ashburn, VA \| Construction One \| Maximum
Real Estate Properties [Line Items]
Date of Construction	2006
Shopping Centers \| Ashland Square Phase I, Dumfries, VA
Real Estate Properties [Line Items]
Initial Basis	1,178
Cost Capitalized Subsequent to Acquisition	7,503
Basis at Close of Period, Land	1,178
Basis at Close of Period, Building and Improvements	7,503
Basis at Close of Period, Leasehold Interests	0
Total	8,681
Accumulated Depreciation	776
Book Value	7,905
Related Debt	0
Date Acquired	2004-12
Shopping Centers \| Ashland Square Phase I, Dumfries, VA \| Minimum
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	20 years
Shopping Centers \| Ashland Square Phase I, Dumfries, VA \| Maximum
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| Ashland Square Phase I, Dumfries, VA \| Construction One
Real Estate Properties [Line Items]
Date of Construction	2007
Shopping Centers \| Ashland Square Phase I, Dumfries, VA \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	2013
Shopping Centers \| Beacon Center, Alexandria, VA
Real Estate Properties [Line Items]
Initial Basis	1,493
Cost Capitalized Subsequent to Acquisition	18,232
Basis at Close of Period, Land	0
Basis at Close of Period, Building and Improvements	18,631
Basis at Close of Period, Leasehold Interests	1,094
Total	19,725
Accumulated Depreciation	12,707
Book Value	7,018
Related Debt	33,140
Date Acquired	1972-01
Shopping Centers \| Beacon Center, Alexandria, VA \| Minimum
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Beacon Center, Alexandria, VA \| Maximum
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| Beacon Center, Alexandria, VA \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1960
Shopping Centers \| Beacon Center, Alexandria, VA \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1974
Shopping Centers \| BJbs Wholesale Club, Alexandria, VA
Real Estate Properties [Line Items]
Initial Basis	22,623
Cost Capitalized Subsequent to Acquisition	0
Basis at Close of Period, Land	22,623
Basis at Close of Period, Building and Improvements	0
Basis at Close of Period, Leasehold Interests	0
Total	22,623
Accumulated Depreciation	0
Book Value	22,623
Related Debt	11,587
Date Acquired	2008-03
Buildings and Improvements Depreciable Lives in Years	0 years
Shopping Centers \| Boca Valley Plaza, Boca Raton, FL
Real Estate Properties [Line Items]
Initial Basis	16,720
Cost Capitalized Subsequent to Acquisition	1,297
Basis at Close of Period, Land	5,735
Basis at Close of Period, Building and Improvements	12,282
Basis at Close of Period, Leasehold Interests	0
Total	18,017
Accumulated Depreciation	3,478
Book Value	14,539
Related Debt	10,881
Date Acquired	2004-02
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Boulevard, Fairfax, VA
Real Estate Properties [Line Items]
Initial Basis	4,883
Cost Capitalized Subsequent to Acquisition	4,487
Basis at Close of Period, Land	3,687
Basis at Close of Period, Building and Improvements	5,683
Basis at Close of Period, Leasehold Interests	0
Total	9,370
Accumulated Depreciation	2,194
Book Value	7,176
Related Debt	9,239
Date Acquired	1994-04
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Boulevard, Fairfax, VA \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1969
Shopping Centers \| Boulevard, Fairfax, VA \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1999
Shopping Centers \| Boulevard, Fairfax, VA \| Construction Three
Real Estate Properties [Line Items]
Date of Construction	2009
Shopping Centers \| Briggs Chaney MarketPlace, Silver Spring, MD
Real Estate Properties [Line Items]
Initial Basis	27,037
Cost Capitalized Subsequent to Acquisition	2,957
Basis at Close of Period, Land	9,789
Basis at Close of Period, Building and Improvements	20,205
Basis at Close of Period, Leasehold Interests	0
Total	29,994
Accumulated Depreciation	6,076
Book Value	23,918
Related Debt	15,761
Date Acquired	2004-04
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Broadlands Village, Ashburn, VA
Real Estate Properties [Line Items]
Initial Basis	5,316
Cost Capitalized Subsequent to Acquisition	25,285
Basis at Close of Period, Land	5,300
Basis at Close of Period, Building and Improvements	25,301
Basis at Close of Period, Leasehold Interests	0
Total	30,601
Accumulated Depreciation	8,354
Book Value	22,247
Related Debt	18,826
Date Acquired	2002-03
Shopping Centers \| Broadlands Village, Ashburn, VA \| Minimum
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Broadlands Village, Ashburn, VA \| Maximum
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| Broadlands Village, Ashburn, VA \| Construction One \| Minimum
Real Estate Properties [Line Items]
Date of Construction	2002
Shopping Centers \| Broadlands Village, Ashburn, VA \| Construction One \| Maximum
Real Estate Properties [Line Items]
Date of Construction	2003
Shopping Centers \| Broadlands Village, Ashburn, VA \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	2004
Shopping Centers \| Broadlands Village, Ashburn, VA \| Construction Three
Real Estate Properties [Line Items]
Date of Construction	2006
Shopping Centers \| Countryside Marketplace, Sterling, VA
Real Estate Properties [Line Items]
Initial Basis	28,912
Cost Capitalized Subsequent to Acquisition	3,039
Basis at Close of Period, Land	7,666
Basis at Close of Period, Building and Improvements	24,285
Basis at Close of Period, Leasehold Interests	0
Total	31,951
Accumulated Depreciation	6,538
Book Value	25,413
Related Debt	15,819
Date Acquired	2004-02
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Cranberry Square, Westminster, MD
Real Estate Properties [Line Items]
Initial Basis	31,578
Cost Capitalized Subsequent to Acquisition	464
Basis at Close of Period, Land	6,700
Basis at Close of Period, Building and Improvements	25,342
Basis at Close of Period, Leasehold Interests	0
Total	32,042
Accumulated Depreciation	2,061
Book Value	29,981
Related Debt	18,645
Date Acquired	2011-09
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Cruse MarketPlace, Cumming, GA
Real Estate Properties [Line Items]
Initial Basis	12,226
Cost Capitalized Subsequent to Acquisition	198
Basis at Close of Period, Land	3,920
Basis at Close of Period, Building and Improvements	8,504
Basis at Close of Period, Leasehold Interests	0
Total	12,424
Accumulated Depreciation	2,350
Book Value	10,074
Related Debt	0
Date Acquired	2004-03
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Flagship Center, Rockville, MD
Real Estate Properties [Line Items]
Initial Basis	160
Cost Capitalized Subsequent to Acquisition	9
Basis at Close of Period, Land	169
Basis at Close of Period, Building and Improvements	0
Basis at Close of Period, Leasehold Interests	0
Total	169
Accumulated Depreciation	0
Book Value	169
Related Debt	0
Date of Construction	1972
Date Acquired	1972-01
Buildings and Improvements Depreciable Lives in Years	0 years
Shopping Centers \| French Market, Oklahoma City, OK
Real Estate Properties [Line Items]
Initial Basis	5,781
Cost Capitalized Subsequent to Acquisition	13,782
Basis at Close of Period, Land	1,118
Basis at Close of Period, Building and Improvements	18,445
Basis at Close of Period, Leasehold Interests	0
Total	19,563
Accumulated Depreciation	9,444
Book Value	10,119
Related Debt	0
Date Acquired	1974-03
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| French Market, Oklahoma City, OK \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1972
Shopping Centers \| French Market, Oklahoma City, OK \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1998
Shopping Centers \| Germantown, Germantown, MD
Real Estate Properties [Line Items]
Initial Basis	3,576
Cost Capitalized Subsequent to Acquisition	743
Basis at Close of Period, Land	2,034
Basis at Close of Period, Building and Improvements	2,285
Basis at Close of Period, Leasehold Interests	0
Total	4,319
Accumulated Depreciation	1,385
Book Value	2,934
Related Debt	0
Date of Construction	1990
Date Acquired	1993-08
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| 750/730 N. Glebe Road, Arlington, VA
Real Estate Properties [Line Items]
Initial Basis	42,313
Cost Capitalized Subsequent to Acquisition	13
Basis at Close of Period, Land	40,907
Basis at Close of Period, Building and Improvements	1,419
Basis at Close of Period, Leasehold Interests	0
Total	42,326
Accumulated Depreciation	160
Book Value	42,166
Related Debt	0
Shopping Centers \| 750/730 N. Glebe Road, Arlington, VA \| Acquisition Date One
Real Estate Properties [Line Items]
Date Acquired	2014-08
Buildings and Improvements Depreciable Lives in Years	3 years
Shopping Centers \| 750/730 N. Glebe Road, Arlington, VA \| Acquisition Date Two
Real Estate Properties [Line Items]
Date Acquired	2014-12
Buildings and Improvements Depreciable Lives in Years	2 years
Shopping Centers \| The Glen, Woodbridge, VA
Real Estate Properties [Line Items]
Initial Basis	12,918
Cost Capitalized Subsequent to Acquisition	7,536
Basis at Close of Period, Land	5,299
Basis at Close of Period, Building and Improvements	15,155
Basis at Close of Period, Leasehold Interests	0
Total	20,454
Accumulated Depreciation	7,327
Book Value	13,127
Related Debt	9,045
Date Acquired	1994-06
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| The Glen, Woodbridge, VA \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1993
Shopping Centers \| The Glen, Woodbridge, VA \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	2005
Shopping Centers \| Great Eastern, District Heights, MD
Real Estate Properties [Line Items]
Initial Basis	4,993
Cost Capitalized Subsequent to Acquisition	10,669
Basis at Close of Period, Land	3,785
Basis at Close of Period, Building and Improvements	11,877
Basis at Close of Period, Leasehold Interests	0
Total	15,662
Accumulated Depreciation	7,726
Book Value	7,936
Related Debt	0
Date Acquired	1972-01
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Great Eastern, District Heights, MD \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1958
Shopping Centers \| Great Eastern, District Heights, MD \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1960
Shopping Centers \| Great Falls Center, Great Falls, VA
Real Estate Properties [Line Items]
Initial Basis	41,750
Cost Capitalized Subsequent to Acquisition	2,350
Basis at Close of Period, Land	14,766
Basis at Close of Period, Building and Improvements	29,334
Basis at Close of Period, Leasehold Interests	0
Total	44,100
Accumulated Depreciation	4,988
Book Value	39,112
Related Debt	14,909
Date Acquired	2008-03
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Hampshire Langley, Takoma, MD
Real Estate Properties [Line Items]
Initial Basis	3,159
Cost Capitalized Subsequent to Acquisition	3,338
Basis at Close of Period, Land	1,856
Basis at Close of Period, Building and Improvements	4,641
Basis at Close of Period, Leasehold Interests	0
Total	6,497
Accumulated Depreciation	3,351
Book Value	3,146
Related Debt	17,281
Date of Construction	1960
Date Acquired	1972-01
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Hunt Club Corners, Apopka, FL
Real Estate Properties [Line Items]
Initial Basis	12,584
Cost Capitalized Subsequent to Acquisition	3,115
Basis at Close of Period, Land	4,822
Basis at Close of Period, Building and Improvements	10,877
Basis at Close of Period, Leasehold Interests	0
Total	15,699
Accumulated Depreciation	2,555
Book Value	13,144
Related Debt	6,100
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Hunt Club Corners, Apopka, FL \| Acquisition Date One
Real Estate Properties [Line Items]
Date Acquired	2006-06
Shopping Centers \| Hunt Club Corners, Apopka, FL \| Acquisition Date Two
Real Estate Properties [Line Items]
Date Acquired	2012-12
Shopping Centers \| Jamestown Place, Altamonte Springs, FL
Real Estate Properties [Line Items]
Initial Basis	14,055
Cost Capitalized Subsequent to Acquisition	960
Basis at Close of Period, Land	4,455
Basis at Close of Period, Building and Improvements	10,560
Basis at Close of Period, Leasehold Interests	0
Total	15,015
Accumulated Depreciation	2,532
Book Value	12,483
Related Debt	8,346
Date Acquired	2005-11
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Kentlands Square I, Gaithersburg, MD
Real Estate Properties [Line Items]
Initial Basis	14,379
Cost Capitalized Subsequent to Acquisition	177
Basis at Close of Period, Land	5,006
Basis at Close of Period, Building and Improvements	9,550
Basis at Close of Period, Leasehold Interests	0
Total	14,556
Accumulated Depreciation	2,958
Book Value	11,598
Related Debt	7,527
Date of Construction	2002
Date Acquired	2002-09
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Kentlands Square II, Gaithersburg, MD
Real Estate Properties [Line Items]
Initial Basis	76,723
Cost Capitalized Subsequent to Acquisition	954
Basis at Close of Period, Land	22,800
Basis at Close of Period, Building and Improvements	54,877
Basis at Close of Period, Leasehold Interests	0
Total	77,677
Accumulated Depreciation	4,387
Book Value	73,290
Related Debt	39,932
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Kentlands Square II, Gaithersburg, MD \| Acquisition Date One
Real Estate Properties [Line Items]
Date Acquired	2011-09
Shopping Centers \| Kentlands Square II, Gaithersburg, MD \| Acquisition Date Two
Real Estate Properties [Line Items]
Date Acquired	2013-09
Shopping Centers \| Kentlands Place, Gaithersburg, MD
Real Estate Properties [Line Items]
Initial Basis	1,425
Cost Capitalized Subsequent to Acquisition	7,163
Basis at Close of Period, Land	1,425
Basis at Close of Period, Building and Improvements	7,163
Basis at Close of Period, Leasehold Interests	0
Total	8,588
Accumulated Depreciation	2,863
Book Value	5,725
Related Debt	0
Date of Construction	2005
Date Acquired	2004-01
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| Lansdowne Town Center, Leesburg, VA
Real Estate Properties [Line Items]
Initial Basis	6,545
Cost Capitalized Subsequent to Acquisition	36,313
Basis at Close of Period, Land	6,546
Basis at Close of Period, Building and Improvements	36,312
Basis at Close of Period, Leasehold Interests	0
Total	42,858
Accumulated Depreciation	10,174
Book Value	32,684
Related Debt	35,222
Date of Construction	2006
Date Acquired	2002-11
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| Leesburg Pike Plaza, Baileys Crossroads, VA
Real Estate Properties [Line Items]
Initial Basis	2,418
Cost Capitalized Subsequent to Acquisition	6,173
Basis at Close of Period, Land	1,132
Basis at Close of Period, Building and Improvements	7,459
Basis at Close of Period, Leasehold Interests	0
Total	8,591
Accumulated Depreciation	5,582
Book Value	3,009
Related Debt	16,750
Date of Construction	1965
Date Acquired	1966-02
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Lumberton Plaza, Lumberton, NJ
Real Estate Properties [Line Items]
Initial Basis	4,400
Cost Capitalized Subsequent to Acquisition	11,160
Basis at Close of Period, Land	950
Basis at Close of Period, Building and Improvements	14,610
Basis at Close of Period, Leasehold Interests	0
Total	15,560
Accumulated Depreciation	11,676
Book Value	3,884
Related Debt	0
Date of Construction	1975
Date Acquired	1975-12
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Metro Pike Center, Rockville, MD
Real Estate Properties [Line Items]
Initial Basis	33,123
Cost Capitalized Subsequent to Acquisition	2,069
Basis at Close of Period, Land	26,064
Basis at Close of Period, Building and Improvements	9,128
Basis at Close of Period, Leasehold Interests	0
Total	35,192
Accumulated Depreciation	771
Book Value	34,421
Related Debt	15,106
Date Acquired	2010-12
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Shops at Monocacy, Frederick, MD
Real Estate Properties [Line Items]
Initial Basis	9,541
Cost Capitalized Subsequent to Acquisition	14,002
Basis at Close of Period, Land	9,260
Basis at Close of Period, Building and Improvements	14,283
Basis at Close of Period, Leasehold Interests	0
Total	23,543
Accumulated Depreciation	4,320
Book Value	19,223
Related Debt	14,014
Date Acquired	2003-11
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| Shops at Monocacy, Frederick, MD \| Construction One \| Minimum
Real Estate Properties [Line Items]
Date of Construction	2003
Shopping Centers \| Shops at Monocacy, Frederick, MD \| Construction One \| Maximum
Real Estate Properties [Line Items]
Date of Construction	2004
Shopping Centers \| Northrock, Warrenton, VA
Real Estate Properties [Line Items]
Initial Basis	12,686
Cost Capitalized Subsequent to Acquisition	14,981
Basis at Close of Period, Land	12,686
Basis at Close of Period, Building and Improvements	14,981
Basis at Close of Period, Leasehold Interests	0
Total	27,667
Accumulated Depreciation	2,283
Book Value	25,384
Related Debt	14,525
Date of Construction	2009
Date Acquired	2008-01
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| Olde Forte Village, Ft. Washington, MD
Real Estate Properties [Line Items]
Initial Basis	15,933
Cost Capitalized Subsequent to Acquisition	6,499
Basis at Close of Period, Land	5,409
Basis at Close of Period, Building and Improvements	17,023
Basis at Close of Period, Leasehold Interests	0
Total	22,432
Accumulated Depreciation	5,583
Book Value	16,849
Related Debt	11,454
Date Acquired	2007-03
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Olde Forte Village, Ft. Washington, MD \| Construction One \| Minimum
Real Estate Properties [Line Items]
Date of Construction	2003
Shopping Centers \| Olde Forte Village, Ft. Washington, MD \| Construction One \| Maximum
Real Estate Properties [Line Items]
Date of Construction	2004
Shopping Centers \| Olney, Olney, MD
Real Estate Properties [Line Items]
Initial Basis	1,884
Cost Capitalized Subsequent to Acquisition	1,672
Basis at Close of Period, Land	0
Basis at Close of Period, Building and Improvements	3,556
Basis at Close of Period, Leasehold Interests	0
Total	3,556
Accumulated Depreciation	3,180
Book Value	376
Related Debt	11,119
Date of Construction	1972
Date Acquired	1975-11
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Orchard Park, Dunwoody, GA
Real Estate Properties [Line Items]
Initial Basis	19,377
Cost Capitalized Subsequent to Acquisition	781
Basis at Close of Period, Land	7,751
Basis at Close of Period, Building and Improvements	12,407
Basis at Close of Period, Leasehold Interests	0
Total	20,158
Accumulated Depreciation	2,343
Book Value	17,815
Related Debt	10,718
Date Acquired	2007-07
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Palm Springs Center, Altamonte Springs, FL
Real Estate Properties [Line Items]
Initial Basis	18,365
Cost Capitalized Subsequent to Acquisition	659
Basis at Close of Period, Land	5,739
Basis at Close of Period, Building and Improvements	13,285
Basis at Close of Period, Leasehold Interests	0
Total	19,024
Accumulated Depreciation	3,247
Book Value	15,777
Related Debt	9,535
Date Acquired	2005-03
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Ravenwood, Baltimore, MD
Real Estate Properties [Line Items]
Initial Basis	1,245
Cost Capitalized Subsequent to Acquisition	4,097
Basis at Close of Period, Land	703
Basis at Close of Period, Building and Improvements	4,639
Basis at Close of Period, Leasehold Interests	0
Total	5,342
Accumulated Depreciation	2,602
Book Value	2,740
Related Debt	15,735
Date Acquired	1972-01
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Ravenwood, Baltimore, MD \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1959
Shopping Centers \| Ravenwood, Baltimore, MD \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	2006
Shopping Centers \| 11503 Rockville Pike/5541 Nicholson Lane, Rockville, MD
Real Estate Properties [Line Items]
Initial Basis	14,861
Cost Capitalized Subsequent to Acquisition	11,700
Basis at Close of Period, Land	22,113
Basis at Close of Period, Building and Improvements	4,448
Basis at Close of Period, Leasehold Interests	0
Total	26,561
Accumulated Depreciation	473
Book Value	26,088
Related Debt	0
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| 11503 Rockville Pike/5541 Nicholson Lane, Rockville, MD \| Acquisition Date One
Real Estate Properties [Line Items]
Date Acquired	2010-10
Shopping Centers \| 11503 Rockville Pike/5541 Nicholson Lane, Rockville, MD \| Acquisition Date Two
Real Estate Properties [Line Items]
Date Acquired	2012-12
Shopping Centers \| 1500/1580/1582/1584 Rockville Pike, Rockville, MD
Real Estate Properties [Line Items]
Initial Basis	51,156
Cost Capitalized Subsequent to Acquisition	568
Basis at Close of Period, Land	43,863
Basis at Close of Period, Building and Improvements	7,861
Basis at Close of Period, Leasehold Interests	0
Total	51,724
Accumulated Depreciation	1,962
Book Value	49,762
Related Debt	0
Date Acquired	2012-12
Shopping Centers \| 1500/1580/1582/1584 Rockville Pike, Rockville, MD \| Acquisition Date Two
Real Estate Properties [Line Items]
Date Acquired	2014-01
Shopping Centers \| 1500/1580/1582/1584 Rockville Pike, Rockville, MD \| Acquisition Date Three
Real Estate Properties [Line Items]
Date Acquired	2014-04
Shopping Centers \| 1500/1580/1582/1584 Rockville Pike, Rockville, MD \| Acquisition Date Four
Real Estate Properties [Line Items]
Date Acquired	2014-12
Shopping Centers \| Seabreeze Plaza, Palm Harbor, FL
Real Estate Properties [Line Items]
Initial Basis	24,526
Cost Capitalized Subsequent to Acquisition	1,391
Basis at Close of Period, Land	8,665
Basis at Close of Period, Building and Improvements	17,252
Basis at Close of Period, Leasehold Interests	0
Total	25,917
Accumulated Depreciation	4,056
Book Value	21,861
Related Debt	17,462
Date Acquired	2005-11
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Market Place at Sea Colony, Bethany Beach, DE
Real Estate Properties [Line Items]
Initial Basis	2,920
Cost Capitalized Subsequent to Acquisition	81
Basis at Close of Period, Land	1,147
Basis at Close of Period, Building and Improvements	1,854
Basis at Close of Period, Leasehold Interests	0
Total	3,001
Accumulated Depreciation	320
Book Value	2,681
Related Debt	0
Date Acquired	2008-03
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Seven Corners, Falls Church, VA
Real Estate Properties [Line Items]
Initial Basis	4,848
Cost Capitalized Subsequent to Acquisition	43,692
Basis at Close of Period, Land	4,913
Basis at Close of Period, Building and Improvements	43,627
Basis at Close of Period, Leasehold Interests	0
Total	48,540
Accumulated Depreciation	25,486
Book Value	23,054
Related Debt	69,397
Date Acquired	1973-07
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Seven Corners, Falls Church, VA \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1956
Shopping Centers \| Seven Corners, Falls Church, VA \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1997
Shopping Centers \| Severna Park Marketplace, Severna Park, MD
Real Estate Properties [Line Items]
Initial Basis	63,254
Cost Capitalized Subsequent to Acquisition	63
Basis at Close of Period, Land	12,700
Basis at Close of Period, Building and Improvements	50,617
Basis at Close of Period, Leasehold Interests	0
Total	63,317
Accumulated Depreciation	4,112
Book Value	59,205
Related Debt	35,125
Date Acquired	2011-09
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Shops at Fairfax, Fairfax, VA
Real Estate Properties [Line Items]
Initial Basis	2,708
Cost Capitalized Subsequent to Acquisition	9,898
Basis at Close of Period, Land	992
Basis at Close of Period, Building and Improvements	11,614
Basis at Close of Period, Leasehold Interests	0
Total	12,606
Accumulated Depreciation	6,914
Book Value	5,692
Related Debt	6,160
Date Acquired	1975-06
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| Shops at Fairfax, Fairfax, VA \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1975
Shopping Centers \| Shops at Fairfax, Fairfax, VA \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1999
Shopping Centers \| Smallwood Village Center, Waldorf, MD
Real Estate Properties [Line Items]
Initial Basis	17,819
Cost Capitalized Subsequent to Acquisition	7,618
Basis at Close of Period, Land	6,402
Basis at Close of Period, Building and Improvements	19,035
Basis at Close of Period, Leasehold Interests	0
Total	25,437
Accumulated Depreciation	5,025
Book Value	20,412
Related Debt	0
Date Acquired	2006-01
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Southdale, Glen Burnie, MD
Real Estate Properties [Line Items]
Initial Basis	3,650
Cost Capitalized Subsequent to Acquisition	20,919
Basis at Close of Period, Land	0
Basis at Close of Period, Building and Improvements	23,947
Basis at Close of Period, Leasehold Interests	622
Total	24,569
Accumulated Depreciation	20,467
Book Value	4,102
Related Debt	0
Date Acquired	1972-01
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Southdale, Glen Burnie, MD \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1962
Shopping Centers \| Southdale, Glen Burnie, MD \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1986
Shopping Centers \| Southside Plaza, Richmond, VA
Real Estate Properties [Line Items]
Initial Basis	6,728
Cost Capitalized Subsequent to Acquisition	9,597
Basis at Close of Period, Land	1,878
Basis at Close of Period, Building and Improvements	14,447
Basis at Close of Period, Leasehold Interests	0
Total	16,325
Accumulated Depreciation	11,100
Book Value	5,225
Related Debt	0
Date of Construction	1958
Date Acquired	1972-01
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| South Dekalb Plaza, Atlanta, GA
Real Estate Properties [Line Items]
Initial Basis	2,474
Cost Capitalized Subsequent to Acquisition	3,899
Basis at Close of Period, Land	703
Basis at Close of Period, Building and Improvements	5,670
Basis at Close of Period, Leasehold Interests	0
Total	6,373
Accumulated Depreciation	4,285
Book Value	2,088
Related Debt	0
Date of Construction	1970
Date Acquired	1976-02
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Thruway, Winston-Salem, NC
Real Estate Properties [Line Items]
Initial Basis	4,778
Cost Capitalized Subsequent to Acquisition	23,157
Basis at Close of Period, Land	5,496
Basis at Close of Period, Building and Improvements	22,334
Basis at Close of Period, Leasehold Interests	105
Total	27,935
Accumulated Depreciation	13,715
Book Value	14,220
Related Debt	41,441
Date Acquired	1972-05
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Thruway, Winston-Salem, NC \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1955
Shopping Centers \| Thruway, Winston-Salem, NC \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1965
Shopping Centers \| Village Center, Centreville, VA
Real Estate Properties [Line Items]
Initial Basis	16,502
Cost Capitalized Subsequent to Acquisition	1,870
Basis at Close of Period, Land	7,851
Basis at Close of Period, Building and Improvements	10,521
Basis at Close of Period, Leasehold Interests	0
Total	18,372
Accumulated Depreciation	5,713
Book Value	12,659
Related Debt	14,535
Date of Construction	1990
Date Acquired	1993-08
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| Westview Village, Frederick, MD
Real Estate Properties [Line Items]
Initial Basis	5,146
Cost Capitalized Subsequent to Acquisition	22,292
Basis at Close of Period, Land	5,153
Basis at Close of Period, Building and Improvements	22,285
Basis at Close of Period, Leasehold Interests	0
Total	27,438
Accumulated Depreciation	4,245
Book Value	23,193
Related Debt	0
Date of Construction	2009
Date Acquired	2011-07
Buildings and Improvements Depreciable Lives in Years	50 years
Shopping Centers \| White Oak, Silver Spring, MD
Real Estate Properties [Line Items]
Initial Basis	6,277
Cost Capitalized Subsequent to Acquisition	5,311
Basis at Close of Period, Land	4,649
Basis at Close of Period, Building and Improvements	6,939
Basis at Close of Period, Leasehold Interests	0
Total	11,588
Accumulated Depreciation	5,604
Book Value	5,984
Related Debt	25,639
Date Acquired	1972-01
Buildings and Improvements Depreciable Lives in Years	40 years
Shopping Centers \| White Oak, Silver Spring, MD \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1958
Shopping Centers \| White Oak, Silver Spring, MD \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1967
Shopping Centers \| Other Buildings / Improvements
Real Estate Properties [Line Items]
Cost Capitalized Subsequent to Acquisition	115
Basis at Close of Period, Building and Improvements	115
Total	115
Accumulated Depreciation	84
Book Value	31
Related Debt	0
Mixed-Use Properties
Real Estate Properties [Line Items]
Initial Basis	45,179
Cost Capitalized Subsequent to Acquisition	333,883
Basis at Close of Period, Land	26,858
Basis at Close of Period, Building and Improvements	352,204
Basis at Close of Period, Leasehold Interests	0
Total	379,062
Accumulated Depreciation	126,217
Book Value	252,845
Related Debt	177,769
Mixed-Use Properties \| 1500/1580/1582/1584 Rockville Pike, Rockville, MD \| Acquisition Date One
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	5 years
Mixed-Use Properties \| 1500/1580/1582/1584 Rockville Pike, Rockville, MD \| Acquisition Date Two
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	10 years
Mixed-Use Properties \| 1500/1580/1582/1584 Rockville Pike, Rockville, MD \| Acquisition Date Three
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	5 years
Mixed-Use Properties \| 1500/1580/1582/1584 Rockville Pike, Rockville, MD \| Acquisition Date Four
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	4 years
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD
Real Estate Properties [Line Items]
Initial Basis	21,459
Cost Capitalized Subsequent to Acquisition	27,945
Basis at Close of Period, Land	3,756
Basis at Close of Period, Building and Improvements	45,648
Basis at Close of Period, Leasehold Interests	0
Total	49,404
Accumulated Depreciation	31,663
Book Value	17,741
Related Debt	30,429
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Minimum
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	35 years
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Maximum
Real Estate Properties [Line Items]
Buildings and Improvements Depreciable Lives in Years	40 years
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1984
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	1986
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Construction Three
Real Estate Properties [Line Items]
Date of Construction	1990
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Construction Four
Real Estate Properties [Line Items]
Date of Construction	1998
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Construction Five
Real Estate Properties [Line Items]
Date of Construction	2000
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Acquisition Date One
Real Estate Properties [Line Items]
Date Acquired	1984-12
Mixed-Use Properties \| Avenel Business Park, Gaithersburg, MD \| Acquisition Date Two
Real Estate Properties [Line Items]
Date Acquired	1984-02
Mixed-Use Properties \| Clarendon Center, Arlington, VA (1)
Real Estate Properties [Line Items]
Initial Basis	12,753	[1]
Cost Capitalized Subsequent to Acquisition	185,485	[1]
Basis at Close of Period, Land	16,287	[1]
Basis at Close of Period, Building and Improvements	181,951	[1]
Basis at Close of Period, Leasehold Interests	0	[1]
Total	198,238	[1]
Accumulated Depreciation	21,709	[1]
Book Value	176,529	[1]
Related Debt	115,291	[1]
Date of Construction	2010	[1]
Mixed-Use Properties \| Clarendon Center, Arlington, VA (1) \| Acquisition Date One
Real Estate Properties [Line Items]
Date Acquired	1973-07	[1]
Mixed-Use Properties \| Clarendon Center, Arlington, VA (1) \| Acquisition Date Two
Real Estate Properties [Line Items]
Date Acquired	1996-01	[1]
Mixed-Use Properties \| Clarendon Center, Arlington, VA (1) \| Acquisition Date Three
Real Estate Properties [Line Items]
Date Acquired	2002-04	[1]
Mixed-Use Properties \| Crosstown Business Center, Tulsa, OK
Real Estate Properties [Line Items]
Initial Basis	3,454
Cost Capitalized Subsequent to Acquisition	6,358
Basis at Close of Period, Land	604
Basis at Close of Period, Building and Improvements	9,208
Basis at Close of Period, Leasehold Interests	0
Total	9,812
Accumulated Depreciation	6,792
Book Value	3,020
Related Debt	0
Date of Construction	1974
Date Acquired	1975-10
Buildings and Improvements Depreciable Lives in Years	40 years
Mixed-Use Properties \| 601 Pennsylvania Ave., Washington, DC
Real Estate Properties [Line Items]
Initial Basis	5,479
Cost Capitalized Subsequent to Acquisition	62,169
Basis at Close of Period, Land	5,667
Basis at Close of Period, Building and Improvements	61,981
Basis at Close of Period, Leasehold Interests	0
Total	67,648
Accumulated Depreciation	46,500
Book Value	21,148
Related Debt	0
Date of Construction	1986
Date Acquired	1973-07
Buildings and Improvements Depreciable Lives in Years	35 years
Mixed-Use Properties \| Washington Square, Alexandria, VA
Real Estate Properties [Line Items]
Initial Basis	2,034
Cost Capitalized Subsequent to Acquisition	51,926
Basis at Close of Period, Land	544
Basis at Close of Period, Building and Improvements	53,416
Basis at Close of Period, Leasehold Interests	0
Total	53,960
Accumulated Depreciation	19,553
Book Value	34,407
Related Debt	32,049
Date Acquired	1973-07
Buildings and Improvements Depreciable Lives in Years	50 years
Mixed-Use Properties \| Washington Square, Alexandria, VA \| Construction One
Real Estate Properties [Line Items]
Date of Construction	1952
Mixed-Use Properties \| Washington Square, Alexandria, VA \| Construction Two
Real Estate Properties [Line Items]
Date of Construction	2000
Development Land
Real Estate Properties [Line Items]
Initial Basis	9,622
Cost Capitalized Subsequent to Acquisition	2,003
Basis at Close of Period, Land	11,625
Basis at Close of Period, Building and Improvements	24,755
Basis at Close of Period, Leasehold Interests	0
Total	36,380
Accumulated Depreciation	0
Book Value	36,380
Development Land, Related Debt	5,391
Development Land \| Ashland Square Phase II, Manassas, VA
Real Estate Properties [Line Items]
Initial Basis	5,292
Cost Capitalized Subsequent to Acquisition	1,717
Basis at Close of Period, Land	7,009
Basis at Close of Period, Building and Improvements	0
Basis at Close of Period, Leasehold Interests	0
Total	7,009
Accumulated Depreciation	0
Book Value	7,009
Development Land, Related Debt	0
Date Acquired	2004-12
Development Land \| New Market, New Market, MD
Real Estate Properties [Line Items]
Initial Basis	2,088
Cost Capitalized Subsequent to Acquisition	286
Basis at Close of Period, Land	2,374
Basis at Close of Period, Building and Improvements	0
Basis at Close of Period, Leasehold Interests	0
Total	2,374
Accumulated Depreciation	0
Book Value	2,374
Development Land, Related Debt	0
Date Acquired	2005-09
Development Land \| Park Van Ness, Washington, DC
Real Estate Properties [Line Items]
Initial Basis	2,242
Cost Capitalized Subsequent to Acquisition	0
Basis at Close of Period, Land	2,242
Basis at Close of Period, Building and Improvements	24,755
Basis at Close of Period, Leasehold Interests	0
Total	26,997
Accumulated Depreciation	0
Book Value	26,997
Development Land, Related Debt	$5,391
Development Land \| Park Van Ness, Washington, DC \| Development Date One
Real Estate Properties [Line Items]
Date Acquired	1973-07
Development Land \| Park Van Ness, Washington, DC \| Development Date Two
Real Estate Properties [Line Items]
Date Acquired	2011-02

[1]	Includes the North and South Blocks and Residential

Real_Estate_and_Accumulated_De2

Real Estate and Accumulated Depreciation - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Billions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Real estate investments for federal income tax	$1.20	$1.10

Real_Estate_and_Accumulated_De3

Real Estate and Accumulated Depreciation - Estimated Useful Lives of Assets (Detail)	12 Months Ended
	Dec. 31, 2014
Base Building \| Minimum
Property Plant and Equipment Estimated Useful Lives [Line Items]
Estimated useful life	35 years
Base Building \| Maximum
Property Plant and Equipment Estimated Useful Lives [Line Items]
Estimated useful life	50 years
Building Components \| Maximum
Property Plant and Equipment Estimated Useful Lives [Line Items]
Estimated useful life	20 years
Tenant Improvements
Property Plant and Equipment Estimated Useful Lives [Line Items]
Tenant improvements	The shorter of the term of the lease or the useful life of the improvements

Real_Estate_and_Accumulated_De4

Real Estate and Accumulated Depreciation - Changes in Total Real Estate Investments and Related Accumulated Depreciation (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Total real estate investments:
Balance, beginning of year	$1,459,439	$1,466,068	$1,417,845
Acquisitions	70,921	5,124	34,247
Improvements	34,417	21,991	23,095
Retirements	-4,618	-33,744	-9,119
Balance, end of year	1,560,159	1,459,439	1,466,068
Total accumulated depreciation:
Balance, beginning of year	364,663	353,305	326,397
Depreciation expense	35,933	43,204	34,565
Retirements	-3,979	-31,846	-7,657
Balance, end of year	$396,617	$364,663	$353,305