Schedule III - Consolidated Real Estate Investments and Accumulated Depreciation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			$ 258,013
Land			79,448
Building and improvements			145,185
Cost capitalized Subsequent to Acquisition			408,958
Land			79,448
Building and improvements			554,143
Total			633,591
Accumulated Depreciation	$ 116,099	$ 105,228	125,380
Net Carrying Amount			508,211
Real estate investments
Balance at beginning of the year	595,000	462,976
Construction costs and improvements	52,533	106,977
Acquisitions	83,230	45,300
Dispositions	(23,181)	(5,471)
Reclassifications	(73,991)	(14,782)
Balance at end of the year	633,591	595,000
Accumulated Depreciation
Balance at beginning of the year	116,099	105,228
Dispositions	(668)	(957)
Reclassifications	(8,729)	(3,156)
Depreciation	18,678	14,984
Balance at end of the year	$ 125,380	$ 116,099
Building [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation
Buildings	39 years
Tenant Improvements [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation
Tenant improvements	Term of the related lease(or estimated useful life, if shorter)
Office Real Estate
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			42,946
Land			4,685
Building and improvements			10,269
Cost capitalized Subsequent to Acquisition			148,444
Land			4,685
Building and improvements			158,713
Total			163,398
Accumulated Depreciation	$ 50,766		50,766
Net Carrying Amount			112,632
Accumulated Depreciation
Balance at end of the year	50,766
Office Real Estate | 4525 Main Street
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			31,613
Land			982
Cost capitalized Subsequent to Acquisition			39,756
Land			982
Building and improvements			39,756
Total			40,738
Accumulated Depreciation	1,725		1,725
Net Carrying Amount			39,013
Accumulated Depreciation
Balance at end of the year	1,725
Office Real Estate | Armada Hoffler Tower
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			1,976
Cost capitalized Subsequent to Acquisition			55,927
Land			1,976
Building and improvements			55,927
Total			57,903
Accumulated Depreciation	25,569		25,569
Net Carrying Amount			32,334
Accumulated Depreciation
Balance at end of the year	25,569
Office Real Estate | Brooks Crossing
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			121
Cost capitalized Subsequent to Acquisition			7,562
Land			121
Building and improvements			7,562
Total			7,683
Net Carrying Amount			7,683
Office Real Estate | Commonwealth of Virginia - Chesapeake
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			4,933
Land			328
Cost capitalized Subsequent to Acquisition			6,208
Land			328
Building and improvements			6,208
Total			6,536
Accumulated Depreciation	294		294
Net Carrying Amount			6,242
Accumulated Depreciation
Balance at end of the year	294
Office Real Estate | Commonwealth of Virginia - Virginia Beach
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			208
Cost capitalized Subsequent to Acquisition			2,159
Land			208
Building and improvements			2,159
Total			2,367
Accumulated Depreciation	86		86
Net Carrying Amount			2,281
Accumulated Depreciation
Balance at end of the year	86
Office Real Estate | One Columbus
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			960
Building and improvements			10,269
Cost capitalized Subsequent to Acquisition			6,946
Land			960
Building and improvements			17,215
Total			18,175
Accumulated Depreciation	9,045		9,045
Net Carrying Amount			9,130
Accumulated Depreciation
Balance at end of the year	9,045
Office Real Estate | Oyster Point
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			6,400
Land			57
Cost capitalized Subsequent to Acquisition			11,595
Land			57
Building and improvements			11,595
Total			11,652
Accumulated Depreciation	8,927		8,927
Net Carrying Amount			2,725
Accumulated Depreciation
Balance at end of the year	8,927
Office Real Estate | Two Columbus
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			53
Cost capitalized Subsequent to Acquisition			18,291
Land			53
Building and improvements			18,291
Total			18,344
Accumulated Depreciation	5,120		5,120
Net Carrying Amount			13,224
Accumulated Depreciation
Balance at end of the year	5,120
Retail Real Estate
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			97,858
Land			67,725
Building and improvements			76,317
Cost capitalized Subsequent to Acquisition			142,312
Land			67,725
Building and improvements			218,629
Total			286,354
Accumulated Depreciation	52,139		52,139
Net Carrying Amount			234,215
Accumulated Depreciation
Balance at end of the year	52,139
Retail Real Estate | 249 Central Park Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			15,282
Land			713
Cost capitalized Subsequent to Acquisition			13,728
Land			713
Building and improvements			13,728
Total			14,441
Accumulated Depreciation	6,998		6,998
Net Carrying Amount			7,443
Accumulated Depreciation
Balance at end of the year	6,998
Retail Real Estate | Bermuda Crossroads
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			5,450
Building and improvements			10,641
Cost capitalized Subsequent to Acquisition			541
Land			5,450
Building and improvements			11,182
Total			16,632
Accumulated Depreciation	1,373		1,373
Net Carrying Amount			15,259
Accumulated Depreciation
Balance at end of the year	1,373
Retail Real Estate | Broad Creek Shopping Center
SEC Schedule III, Real Estate and Accumulated Depreciation
Cost capitalized Subsequent to Acquisition			15,692
Building and improvements			15,692
Total			15,692
Accumulated Depreciation	7,894		7,894
Net Carrying Amount			7,798
Accumulated Depreciation
Balance at end of the year	7,894
Retail Real Estate | Columbus Village
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			8,739
Land			7,630
Building and improvements			10,135
Land			7,630
Building and improvements			10,135
Total			17,765
Accumulated Depreciation	146		146
Net Carrying Amount			17,619
Accumulated Depreciation
Balance at end of the year	146
Retail Real Estate | Commerce Street Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			118
Cost capitalized Subsequent to Acquisition			3,147
Land			118
Building and improvements			3,147
Total			3,265
Accumulated Depreciation	1,007		1,007
Net Carrying Amount			2,258
Accumulated Depreciation
Balance at end of the year	1,007
Retail Real Estate | Courthouse 7-Eleven
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			1,007
Cost capitalized Subsequent to Acquisition			1,043
Land			1,007
Building and improvements			1,043
Total			2,050
Accumulated Depreciation	109		109
Net Carrying Amount			1,941
Accumulated Depreciation
Balance at end of the year	109
Retail Real Estate | Dick's at Town Center
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			67
Cost capitalized Subsequent to Acquisition			10,576
Land			67
Building and improvements			10,576
Total			10,643
Accumulated Depreciation	3,102		3,102
Net Carrying Amount			7,541
Accumulated Depreciation
Balance at end of the year	3,102
Retail Real Estate | Dimmock Square
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			5,100
Building and improvements			13,126
Cost capitalized Subsequent to Acquisition			9
Land			5,100
Building and improvements			13,135
Total			18,235
Accumulated Depreciation	512		512
Net Carrying Amount			17,723
Accumulated Depreciation
Balance at end of the year	512
Retail Real Estate | Fountain Plaza Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			7,641
Land			425
Cost capitalized Subsequent to Acquisition			7,085
Land			425
Building and improvements			7,085
Total			7,510
Accumulated Depreciation	2,750		2,750
Net Carrying Amount			4,760
Accumulated Depreciation
Balance at end of the year	2,750
Retail Real Estate | Gainsborough Square
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			2,229
Cost capitalized Subsequent to Acquisition			6,873
Land			2,229
Building and improvements			6,873
Total			9,102
Accumulated Depreciation	2,821		2,821
Net Carrying Amount			6,281
Accumulated Depreciation
Balance at end of the year	2,821
Retail Real Estate | Greentree Shopping Center
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			1,523
Cost capitalized Subsequent to Acquisition			4,022
Land			1,523
Building and improvements			4,022
Total			5,545
Accumulated Depreciation	186		186
Net Carrying Amount			5,359
Accumulated Depreciation
Balance at end of the year	186
Retail Real Estate | Hanbury Village
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			20,970
Land			3,792
Cost capitalized Subsequent to Acquisition			19,223
Land			3,792
Building and improvements			19,223
Total			23,015
Accumulated Depreciation	5,153		5,153
Net Carrying Amount			17,862
Accumulated Depreciation
Balance at end of the year	5,153
Retail Real Estate | Harrisonburg Regal
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			3,463
Land			1,554
Cost capitalized Subsequent to Acquisition			4,148
Land			1,554
Building and improvements			4,148
Total			5,702
Accumulated Depreciation	1,772		1,772
Net Carrying Amount			3,930
Accumulated Depreciation
Balance at end of the year	1,772
Retail Real Estate | Lightfoot Marketplace
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			7,759
Land			7,628
Cost capitalized Subsequent to Acquisition			7,856
Land			7,628
Building and improvements			7,856
Total			15,484
Net Carrying Amount			15,484
Retail Real Estate | North Point Center
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			13,295
Land			1,936
Cost capitalized Subsequent to Acquisition			25,018
Land			1,936
Building and improvements			25,018
Total			26,954
Accumulated Depreciation	10,945		10,945
Net Carrying Amount			16,009
Accumulated Depreciation
Balance at end of the year	10,945
Retail Real Estate | Parkway Marketplace
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			1,150
Cost capitalized Subsequent to Acquisition			3,507
Land			1,150
Building and improvements			3,507
Total			4,657
Accumulated Depreciation	1,588		1,588
Net Carrying Amount			3,069
Accumulated Depreciation
Balance at end of the year	1,588
Retail Real Estate | Perry Hall Marketplace
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			3,240
Building and improvements			8,316
Land			3,240
Building and improvements			8,316
Total			11,556
Accumulated Depreciation	234		234
Net Carrying Amount			11,322
Accumulated Depreciation
Balance at end of the year	234
Retail Real Estate | Providence Plaza
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			9,950
Building and improvements			12,369
Cost capitalized Subsequent to Acquisition			10
Land			9,950
Building and improvements			12,379
Total			22,329
Accumulated Depreciation	124		124
Net Carrying Amount			22,205
Accumulated Depreciation
Balance at end of the year	124
Retail Real Estate | Sandbridge Commons
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			9,010
Land			5,267
Cost capitalized Subsequent to Acquisition			6,594
Land			5,267
Building and improvements			6,594
Total			11,861
Accumulated Depreciation	200		200
Net Carrying Amount			11,661
Accumulated Depreciation
Balance at end of the year	200
Retail Real Estate | Socastee Commons
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			4,957
Land			2,320
Building and improvements			5,380
Cost capitalized Subsequent to Acquisition			42
Land			2,320
Building and improvements			5,422
Total			7,742
Accumulated Depreciation	103		103
Net Carrying Amount			7,639
Accumulated Depreciation
Balance at end of the year	103
Retail Real Estate | South Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			6,742
Land			190
Cost capitalized Subsequent to Acquisition			7,333
Land			190
Building and improvements			7,333
Total			7,523
Accumulated Depreciation	3,491		3,491
Net Carrying Amount			4,032
Accumulated Depreciation
Balance at end of the year	3,491
Retail Real Estate | Stone House Square
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			6,360
Building and improvements			16,350
Cost capitalized Subsequent to Acquisition			82
Land			6,360
Building and improvements			16,432
Total			22,792
Accumulated Depreciation	413		413
Net Carrying Amount			22,379
Accumulated Depreciation
Balance at end of the year	413
Retail Real Estate | Studio 56 Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			76
Cost capitalized Subsequent to Acquisition			2,477
Land			76
Building and improvements			2,477
Total			2,553
Accumulated Depreciation	628		628
Net Carrying Amount			1,925
Accumulated Depreciation
Balance at end of the year	628
Retail Real Estate | Tyre Neck Harris Teeter
SEC Schedule III, Real Estate and Accumulated Depreciation
Cost capitalized Subsequent to Acquisition			3,306
Building and improvements			3,306
Total			3,306
Accumulated Depreciation	590		590
Net Carrying Amount			2,716
Accumulated Depreciation
Balance at end of the year	590
Multifamily Residential Real Estate
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			117,209
Land			5,858
Building and improvements			58,599
Cost capitalized Subsequent to Acquisition			118,202
Land			5,858
Building and improvements			176,801
Total			182,659
Accumulated Depreciation	22,475		22,475
Net Carrying Amount			160,184
Accumulated Depreciation
Balance at end of the year	22,475
Multifamily Residential Real Estate | Encore Apartments
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			25,184
Land			1,293
Cost capitalized Subsequent to Acquisition			30,069
Land			1,293
Building and improvements			30,069
Total			31,362
Accumulated Depreciation	972		972
Net Carrying Amount			30,390
Accumulated Depreciation
Balance at end of the year	972
Multifamily Residential Real Estate | Liberty Apartments
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			20,312
Land			3,580
Building and improvements			23,494
Cost capitalized Subsequent to Acquisition			1,188
Land			3,580
Building and improvements			24,682
Total			28,262
Accumulated Depreciation	1,668		1,668
Net Carrying Amount			26,594
Accumulated Depreciation
Balance at end of the year	1,668
Multifamily Residential Real Estate | Johns Hopkins Village
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			3,968
Cost capitalized Subsequent to Acquisition			29,438
Building and improvements			29,438
Total			29,438
Net Carrying Amount			29,438
Multifamily Residential Real Estate | Smith's Landing
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			21,226
Building and improvements			35,105
Cost capitalized Subsequent to Acquisition			843
Building and improvements			35,948
Total			35,948
Accumulated Depreciation	3,040		3,040
Net Carrying Amount			32,908
Accumulated Depreciation
Balance at end of the year	3,040
Multifamily Residential Real Estate | The Cosmopolitan
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			46,519
Land			985
Cost capitalized Subsequent to Acquisition			56,664
Land			985
Building and improvements			56,664
Total			57,649
Accumulated Depreciation	16,795		16,795
Net Carrying Amount			40,854
Accumulated Depreciation
Balance at end of the year	$ 16,795
Held for development
SEC Schedule III, Real Estate and Accumulated Depreciation
Land			1,180
Land			1,180
Total			1,180
Net Carrying Amount			$ 1,180
Minimum | Capital Improvements [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation
Buildings	15 years
Minimum | Equipment [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation
Buildings	5 years
Maximum | Capital Improvements [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation
Buildings	20 years
Maximum | Equipment [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation
Buildings	15 years