Schedule III - Consolidated Real Estate Investments and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			$ 307,412
Land			197,777
Building and Improvements			289,145
Cost Capitalized Subsequent to Acquisition			507,516
Land			197,777
Building and improvements			796,660
Total			994,437
Accumulated Depreciation	$ 139,553	$ 125,380	164,521
Net Carrying Amount			829,916
Amount of real estate for federal income tax purposes			698,100
Real estate investments
Balance at beginning of the year	908,287	633,591
Construction costs and improvements	84,142	56,630
Acquisitions	12,760	248,987
Dispositions	(10,146)	(30,467)
Reclassifications	(606)	(454)
Balance at end of the year	994,437	908,287
Accumulated Depreciation
Balance at beginning of the year	139,553	125,380
Dispositions	(1,006)	(352)
Reclassifications	0	(8,928)
Depreciation	25,974	23,453
Balance at end of the year	$ 164,521	$ 139,553
Buildings
SEC Schedule III, Real Estate and Accumulated Depreciation
Estimated useful lives	39 years
Capital improvements | Minimum
SEC Schedule III, Real Estate and Accumulated Depreciation
Estimated useful lives	15 years
Capital improvements | Maximum
SEC Schedule III, Real Estate and Accumulated Depreciation
Estimated useful lives	20 years
Equipment | Minimum
SEC Schedule III, Real Estate and Accumulated Depreciation
Estimated useful lives	5 years
Equipment | Maximum
SEC Schedule III, Real Estate and Accumulated Depreciation
Estimated useful lives	15 years
Office
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			32,034
Land			3,971
Building and Improvements			10,269
Cost Capitalized Subsequent to Acquisition			131,361
Land			3,971
Building and improvements			141,630
Total			145,601
Accumulated Depreciation	$ 51,268		51,268
Net Carrying Amount			94,333
Accumulated Depreciation
Balance at end of the year	51,268
Office | 4525 Main Street
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			32,034
Land			982
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			45,338
Land			982
Building and improvements			45,338
Total			46,320
Accumulated Depreciation	4,422		4,422
Net Carrying Amount			41,898
Accumulated Depreciation
Balance at end of the year	4,422
Office | Armada Hoffler Tower
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			1,976
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			57,887
Land			1,976
Building and improvements			57,887
Total			59,863
Accumulated Depreciation	29,625		29,625
Net Carrying Amount			30,238
Accumulated Depreciation
Balance at end of the year	29,625
Office | One Columbus
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			960
Building and Improvements			10,269
Cost Capitalized Subsequent to Acquisition			8,772
Land			960
Building and improvements			19,041
Total			20,001
Accumulated Depreciation	10,280		10,280
Net Carrying Amount			9,721
Accumulated Depreciation
Balance at end of the year	10,280
Office | Two Columbus
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			53
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			19,364
Land			53
Building and improvements			19,364
Total			19,417
Accumulated Depreciation	6,941		6,941
Net Carrying Amount			12,476
Accumulated Depreciation
Balance at end of the year	6,941
Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			118,668
Land			166,056
Building and Improvements			220,277
Cost Capitalized Subsequent to Acquisition			158,918
Land			166,056
Building and improvements			379,195
Total			545,251
Accumulated Depreciation	77,680		77,680
Net Carrying Amount			467,571
Accumulated Depreciation
Balance at end of the year	77,680
Retail | 249 Central Park Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			16,851
Land			712
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			15,108
Land			712
Building and improvements			15,108
Total			15,820
Accumulated Depreciation	8,228		8,228
Net Carrying Amount			7,592
Accumulated Depreciation
Balance at end of the year	8,228
Retail | Alexander Pointe
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			4,050
Building and Improvements			4,880
Cost Capitalized Subsequent to Acquisition			58
Land			4,050
Building and improvements			4,938
Total			8,988
Accumulated Depreciation	466		466
Net Carrying Amount			8,522
Accumulated Depreciation
Balance at end of the year	466
Retail | Bermuda Crossroads
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			5,450
Building and Improvements			10,641
Cost Capitalized Subsequent to Acquisition			1,053
Land			5,450
Building and improvements			11,694
Total			17,144
Accumulated Depreciation	2,183		2,183
Net Carrying Amount			14,961
Accumulated Depreciation
Balance at end of the year	2,183
Retail | Broad Creek Shopping Center
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			0
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			15,945
Land			0
Building and improvements			15,945
Total			15,945
Accumulated Depreciation	9,010		9,010
Net Carrying Amount			6,935
Accumulated Depreciation
Balance at end of the year	9,010
Retail | Broadmoor Plaza
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			2,410
Building and Improvements			9,010
Cost Capitalized Subsequent to Acquisition			346
Land			2,410
Building and improvements			9,356
Total			11,766
Accumulated Depreciation	881		881
Net Carrying Amount			10,885
Accumulated Depreciation
Balance at end of the year	881
Retail | Town Center Phase VI
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			117
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			2,213
Land			117
Building and improvements			2,213
Total			2,330
Accumulated Depreciation	88		88
Net Carrying Amount			2,242
Accumulated Depreciation
Balance at end of the year	88
Retail | Columbus Village
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			8,298
Land			7,631
Building and Improvements			10,135
Cost Capitalized Subsequent to Acquisition			9
Land			7,631
Building and improvements			10,144
Total			17,775
Accumulated Depreciation	732		732
Net Carrying Amount			17,043
Accumulated Depreciation
Balance at end of the year	732
Retail | Columbus Village II
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			14,536
Building and Improvements			10,922
Cost Capitalized Subsequent to Acquisition			23
Land			14,536
Building and improvements			10,945
Total			25,481
Accumulated Depreciation	520		520
Net Carrying Amount			24,961
Accumulated Depreciation
Balance at end of the year	520
Retail | Commerce Street Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			118
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			3,220
Land			118
Building and improvements			3,220
Total			3,338
Accumulated Depreciation	1,342		1,342
Net Carrying Amount			1,996
Accumulated Depreciation
Balance at end of the year	1,342
Retail | Courthouse 7-Eleven
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			1,007
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			1,043
Land			1,007
Building and improvements			1,043
Total			2,050
Accumulated Depreciation	163		163
Net Carrying Amount			1,887
Accumulated Depreciation
Balance at end of the year	163
Retail | Dick’s at Town Center
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			67
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			10,572
Land			67
Building and improvements			10,572
Total			10,639
Accumulated Depreciation	3,920		3,920
Net Carrying Amount			6,719
Accumulated Depreciation
Balance at end of the year	3,920
Retail | Dimmock Square
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			5,100
Building and Improvements			13,126
Cost Capitalized Subsequent to Acquisition			188
Land			5,100
Building and improvements			13,314
Total			18,414
Accumulated Depreciation	1,254		1,254
Net Carrying Amount			17,160
Accumulated Depreciation
Balance at end of the year	1,254
Retail | Fountain Plaza Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			10,145
Land			425
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			7,135
Land			425
Building and improvements			7,135
Total			7,560
Accumulated Depreciation	3,154		3,154
Net Carrying Amount			4,406
Accumulated Depreciation
Balance at end of the year	3,154
Retail | Gainsborough Square
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			2,229
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			7,182
Land			2,229
Building and improvements			7,182
Total			9,411
Accumulated Depreciation	3,206		3,206
Net Carrying Amount			6,205
Accumulated Depreciation
Balance at end of the year	3,206
Retail | Greentree Shopping Center
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			1,103
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			4,018
Land			1,103
Building and improvements			4,018
Total			5,121
Accumulated Depreciation	513		513
Net Carrying Amount			4,608
Accumulated Depreciation
Balance at end of the year	513
Retail | Hanbury Village
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			19,503
Land			3,793
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			19,342
Land			3,793
Building and improvements			19,342
Total			23,135
Accumulated Depreciation	6,344		6,344
Net Carrying Amount			16,791
Accumulated Depreciation
Balance at end of the year	6,344
Retail | Harper Hill Commons
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			2,840
Building and Improvements			8,510
Cost Capitalized Subsequent to Acquisition			93
Land			2,840
Building and improvements			8,603
Total			11,443
Accumulated Depreciation	608		608
Net Carrying Amount			10,835
Accumulated Depreciation
Balance at end of the year	608
Retail | Harrisonburg Regal
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			1,554
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			4,148
Land			1,554
Building and improvements			4,148
Total			5,702
Accumulated Depreciation	1,989		1,989
Net Carrying Amount			3,713
Accumulated Depreciation
Balance at end of the year	1,989
Retail | Lightfoot Marketplace
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			10,500
Land			7,628
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			14,714
Land			7,628
Building and improvements			14,714
Total			22,342
Accumulated Depreciation	794		794
Net Carrying Amount			21,548
Accumulated Depreciation
Balance at end of the year	794
Retail | North Hampton Market
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			7,250
Building and Improvements			10,210
Cost Capitalized Subsequent to Acquisition			401
Land			7,250
Building and improvements			10,611
Total			17,861
Accumulated Depreciation	953		953
Net Carrying Amount			16,908
Accumulated Depreciation
Balance at end of the year	953
Retail | North Point Center
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			12,030
Land			1,936
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			25,417
Land			1,936
Building and improvements			25,417
Total			27,353
Accumulated Depreciation	12,652		12,652
Net Carrying Amount			14,701
Accumulated Depreciation
Balance at end of the year	12,652
Retail | Oakland Marketplace
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			1,850
Building and Improvements			3,370
Cost Capitalized Subsequent to Acquisition			26
Land			1,850
Building and improvements			3,396
Total			5,246
Accumulated Depreciation	584		584
Net Carrying Amount			4,662
Accumulated Depreciation
Balance at end of the year	584
Retail | Parkway Marketplace
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			1,150
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			3,664
Land			1,150
Building and improvements			3,664
Total			4,814
Accumulated Depreciation	1,776		1,776
Net Carrying Amount			3,038
Accumulated Depreciation
Balance at end of the year	1,776
Retail | Patterson Place
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			15,059
Building and Improvements			20,180
Cost Capitalized Subsequent to Acquisition			231
Land			15,059
Building and improvements			20,411
Total			35,470
Accumulated Depreciation	1,353		1,353
Net Carrying Amount			34,117
Accumulated Depreciation
Balance at end of the year	1,353
Retail | Perry Hall Marketplace
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			3,240
Building and Improvements			8,316
Cost Capitalized Subsequent to Acquisition			383
Land			3,240
Building and improvements			8,699
Total			11,939
Accumulated Depreciation	872		872
Net Carrying Amount			11,067
Accumulated Depreciation
Balance at end of the year	872
Retail | Providence Plaza
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			9,950
Building and Improvements			12,369
Cost Capitalized Subsequent to Acquisition			670
Land			9,950
Building and improvements			13,039
Total			22,989
Accumulated Depreciation	937		937
Net Carrying Amount			22,052
Accumulated Depreciation
Balance at end of the year	937
Retail | Renaissance Place
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			6,730
Building and Improvements			8,439
Cost Capitalized Subsequent to Acquisition			89
Land			6,730
Building and improvements			8,528
Total			15,258
Accumulated Depreciation	335		335
Net Carrying Amount			14,923
Accumulated Depreciation
Balance at end of the year	335
Retail | Sandbridge Commons
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			8,468
Land			4,825
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			7,285
Land			4,825
Building and improvements			7,285
Total			12,110
Accumulated Depreciation	839		839
Net Carrying Amount			11,271
Accumulated Depreciation
Balance at end of the year	839
Retail | Socastee Commons
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			4,771
Land			2,320
Building and Improvements			5,380
Cost Capitalized Subsequent to Acquisition			121
Land			2,320
Building and improvements			5,501
Total			7,821
Accumulated Depreciation	530		530
Net Carrying Amount			7,291
Accumulated Depreciation
Balance at end of the year	530
Retail | South Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			7,394
Land			190
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			7,635
Land			190
Building and improvements			7,635
Total			7,825
Accumulated Depreciation	3,964		3,964
Net Carrying Amount			3,861
Accumulated Depreciation
Balance at end of the year	3,964
Retail | South Square
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			14,130
Building and Improvements			12,670
Cost Capitalized Subsequent to Acquisition			164
Land			14,130
Building and improvements			12,834
Total			26,964
Accumulated Depreciation	953		953
Net Carrying Amount			26,011
Accumulated Depreciation
Balance at end of the year	953
Retail | Southgate Square
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			20,708
Land			8,890
Building and Improvements			25,950
Cost Capitalized Subsequent to Acquisition			249
Land			8,890
Building and improvements			26,199
Total			35,089
Accumulated Depreciation	1,467		1,467
Net Carrying Amount			33,622
Accumulated Depreciation
Balance at end of the year	1,467
Retail | Southshore Shops
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			1,770
Building and Improvements			6,509
Cost Capitalized Subsequent to Acquisition			16
Land			1,770
Building and improvements			6,525
Total			8,295
Accumulated Depreciation	289		289
Net Carrying Amount			8,006
Accumulated Depreciation
Balance at end of the year	289
Retail | Stone House Square
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			6,360
Building and Improvements			16,350
Cost Capitalized Subsequent to Acquisition			277
Land			6,360
Building and improvements			16,627
Total			22,987
Accumulated Depreciation	1,548		1,548
Net Carrying Amount			21,439
Accumulated Depreciation
Balance at end of the year	1,548
Retail | Studio 56 Retail
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			76
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			2,475
Land			76
Building and improvements			2,475
Total			2,551
Accumulated Depreciation	825		825
Net Carrying Amount			1,726
Accumulated Depreciation
Balance at end of the year	825
Retail | Tyre Neck Harris Teeter
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			0
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			3,306
Land			0
Building and improvements			3,306
Total			3,306
Accumulated Depreciation	923		923
Net Carrying Amount			2,383
Accumulated Depreciation
Balance at end of the year	923
Retail | Waynesboro Commons
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			1,300
Building and Improvements			1,610
Cost Capitalized Subsequent to Acquisition			47
Land			1,300
Building and improvements			1,657
Total			2,957
Accumulated Depreciation	385		385
Net Carrying Amount			2,572
Accumulated Depreciation
Balance at end of the year	385
Retail | Wendover Village
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			18,260
Building and Improvements			21,700
Cost Capitalized Subsequent to Acquisition			52
Land			18,260
Building and improvements			21,752
Total			40,012
Accumulated Depreciation	1,100		1,100
Net Carrying Amount			38,912
Accumulated Depreciation
Balance at end of the year	1,100
Multifamily residential real estate
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			156,710
Land			27,070
Building and Improvements			58,599
Cost Capitalized Subsequent to Acquisition			217,237
Land			27,070
Building and improvements			275,835
Total			302,905
Accumulated Depreciation	35,573		35,573
Net Carrying Amount			267,332
Accumulated Depreciation
Balance at end of the year	35,573
Multifamily residential real estate | Encore Apartments
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			24,966
Land			1,293
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			30,183
Land			1,293
Building and improvements			30,183
Total			31,476
Accumulated Depreciation	3,033		3,033
Net Carrying Amount			28,443
Accumulated Depreciation
Balance at end of the year	3,033
Multifamily residential real estate | Harding Place
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			3,874
Land			5,706
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			22,997
Land			5,706
Building and improvements			22,997
Total			28,703
Accumulated Depreciation	0		0
Net Carrying Amount			28,703
Accumulated Depreciation
Balance at end of the year	0
Multifamily residential real estate | Johns Hopkins Village
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			46,698
Land			0
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			69,229
Land			0
Building and improvements			69,229
Total			69,229
Accumulated Depreciation	3,107		3,107
Net Carrying Amount			66,122
Accumulated Depreciation
Balance at end of the year	3,107
Multifamily residential real estate | 595 King Street
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			7,276
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			5,452
Land			7,276
Building and improvements			5,452
Total			12,728
Accumulated Depreciation	0		0
Net Carrying Amount			12,728
Accumulated Depreciation
Balance at end of the year	0
Multifamily residential real estate | Liberty Apartments
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			14,694
Land			3,580
Building and Improvements			23,494
Cost Capitalized Subsequent to Acquisition			1,407
Land			3,580
Building and improvements			24,900
Total			28,480
Accumulated Depreciation	3,456		3,456
Net Carrying Amount			25,024
Accumulated Depreciation
Balance at end of the year	3,456
Multifamily residential real estate | 530 Meeting Street
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			7,265
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			6,372
Land			7,265
Building and improvements			6,372
Total			13,637
Accumulated Depreciation	0		0
Net Carrying Amount			13,637
Accumulated Depreciation
Balance at end of the year	0
Multifamily residential real estate | Smith’s Landing
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			19,764
Land			0
Building and Improvements			35,105
Cost Capitalized Subsequent to Acquisition			1,765
Land			0
Building and improvements			36,870
Total			36,870
Accumulated Depreciation	5,613		5,613
Net Carrying Amount			31,257
Accumulated Depreciation
Balance at end of the year	5,613
Multifamily residential real estate | The Cosmopolitan
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			45,209
Land			985
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			57,504
Land			985
Building and improvements			57,504
Total			58,489
Accumulated Depreciation	20,364		20,364
Net Carrying Amount			38,125
Accumulated Depreciation
Balance at end of the year	20,364
Multifamily residential real estate | Town Center Phase VI
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			1,505
Land			965
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			22,328
Land			965
Building and improvements			22,328
Total			23,293
Accumulated Depreciation	0		0
Net Carrying Amount			23,293
Accumulated Depreciation
Balance at end of the year	0
Held for development
SEC Schedule III, Real Estate and Accumulated Depreciation
Encumbrances			0
Land			680
Building and Improvements			0
Cost Capitalized Subsequent to Acquisition			0
Land			680
Building and improvements			0
Total			680
Accumulated Depreciation	0		0
Net Carrying Amount			$ 680
Accumulated Depreciation
Balance at end of the year	$ 0