Real Estate Properties - Summary of Properties Disposed (Details) $ in Thousands	1 Months Ended																				3 Months Ended		12 Months Ended
	Dec. 31, 2016 USD ($) ft² building property	Nov. 30, 2016 USD ($) ft² building property	Oct. 31, 2016 USD ($) ft² building property	Aug. 31, 2016 USD ($) ft² building property	Jul. 31, 2016 USD ($) ft² building property	Jun. 30, 2016 USD ($) ft² building property	May 31, 2016 USD ($) ft² building property	Apr. 30, 2016 USD ($) ft² building property	Mar. 31, 2016 USD ($) ft² building property	Feb. 29, 2016 USD ($) ft² building property	Dec. 31, 2015 USD ($) ft² building property	Oct. 31, 2015 USD ($) ft² building property	Sep. 30, 2015 USD ($) ft² building property	Aug. 31, 2015 USD ($) ft² building property	Jun. 30, 2015 USD ($) ft² building property	May 31, 2015 USD ($) ft² building property	Apr. 30, 2015 USD ($) ft² building property	Mar. 31, 2015 USD ($) ft² building property	Jan. 31, 2015 USD ($) ft² building property	Jan. 31, 2013 building	Jun. 30, 2015 USD ($) ft² building property	May 31, 2015 building	Dec. 31, 2016 USD ($) ft² building property	Dec. 31, 2015 USD ($) ft² building property	Dec. 31, 2014 USD ($) building
Real Estate Properties [Line Items]
Number of Buildings																				18
Gain (Loss) on Sale | $																							$ 250,886	$ 84,421	$ 0
Disposed of by Sale
Real Estate Properties [Line Items]
Number of Properties | property																							30	91
Number of Buildings																							62	135	43
Square Footage | ft²																							7,972,692	18,939,185
Gross Sales Price | $																							$ 1,259,895	$ 1,999,413	$ 215,900
Gain (Loss) on Sale | $																							$ 250,761	$ 84,421
Disposed of by Sale | Executive Park
Real Estate Properties [Line Items]
Number of Properties | property										1
Number of Buildings										9
Square Footage | ft²										427,443
Gross Sales Price | $										$ 50,865
Gain (Loss) on Sale | $										$ 16,531
Disposed of by Sale | 3330 N Washington Boulevard
Real Estate Properties [Line Items]
Number of Properties | property									1
Number of Buildings									1
Square Footage | ft²									55,719
Gross Sales Price | $									$ 11,250
Gain (Loss) on Sale | $									$ 5,455
Disposed of by Sale | 111 East Kilbourn Avenue
Real Estate Properties [Line Items]
Number of Properties | property									1
Number of Buildings									1
Square Footage | ft²									373,669
Gross Sales Price | $									$ 60,500
Gain (Loss) on Sale | $									$ 14,687
Disposed of by Sale | 1525 Locust Street
Real Estate Properties [Line Items]
Number of Properties | property								1
Number of Buildings								1
Square Footage | ft²								98,009
Gross Sales Price | $								$ 17,700
Gain (Loss) on Sale | $								$ 8,956
Disposed of by Sale | 633 Ahua Street
Real Estate Properties [Line Items]
Number of Properties | property								1
Number of Buildings								1
Square Footage | ft²								93,141
Gross Sales Price | $								$ 29,000
Gain (Loss) on Sale | $								$ 15,963
Disposed of by Sale | Lakewood on the Park
Real Estate Properties [Line Items]
Number of Properties | property							1
Number of Buildings							2
Square Footage | ft²							180,558
Gross Sales Price | $							$ 37,100
Gain (Loss) on Sale | $							$ 13,616
Disposed of by Sale | Leased Land
Real Estate Properties [Line Items]
Number of Properties | property						1
Number of Buildings						7
Square Footage | ft²						0
Gross Sales Price | $						$ 48,450
Gain (Loss) on Sale | $						$ 15,914
Disposed of by Sale | 9110 East Nichols Avenue
Real Estate Properties [Line Items]
Number of Properties | property						1
Number of Buildings						1
Square Footage | ft²						143,958
Gross Sales Price | $						$ 17,200
Gain (Loss) on Sale | $						$ 642
Disposed of by Sale | 111 River Street
Real Estate Properties [Line Items]
Number of Properties | property					1
Number of Buildings					1
Square Footage | ft²					566,215
Gross Sales Price | $					$ 235,000
Gain (Loss) on Sale | $					$ 78,207
Disposed of by Sale | Sky Park Centre
Real Estate Properties [Line Items]
Number of Properties | property					1
Number of Buildings					2
Square Footage | ft²					63,485
Gross Sales Price | $					$ 13,700
Gain (Loss) on Sale | $					$ 4,746
Disposed of by Sale | Raintree Industrial Park
Real Estate Properties [Line Items]
Number of Properties | property					1
Number of Buildings					12
Square Footage | ft²					563,182
Gross Sales Price | $					$ 11,500
Gain (Loss) on Sale | $					$ (653)
Disposed of by Sale | 8701 N Mopac
Real Estate Properties [Line Items]
Number of Properties | property				1
Number of Buildings				1
Square Footage | ft²				121,901
Gross Sales Price | $				$ 21,500
Gain (Loss) on Sale | $				$ 8,394
Disposed of by Sale | 7800 Shoal Creek Boulevard
Real Estate Properties [Line Items]
Number of Properties | property			1
Number of Buildings			4
Square Footage | ft²			151,917
Gross Sales Price | $			$ 29,210
Gain (Loss) on Sale | $			$ 14,908
Disposed of by Sale | 1200 Lakeside Drive
Real Estate Properties [Line Items]
Number of Properties | property		1
Number of Buildings		1
Square Footage | ft²		260,084
Gross Sales Price | $		$ 65,270
Gain (Loss) on Sale | $		$ 3,062
Disposed of by Sale | 6200 Glenn Carlson Drive
Real Estate Properties [Line Items]
Number of Properties | property	1
Number of Buildings	1
Square Footage | ft²	338,000
Gross Sales Price | $	$ 23,050
Gain (Loss) on Sale | $	$ 7,706
Disposed of by Sale | 812 San Antonio Street
Real Estate Properties [Line Items]
Number of Properties | property							1
Number of Buildings							1
Square Footage | ft²							59,321
Disposed of by Sale | 1601 Rio Grande Street
Real Estate Properties [Line Items]
Number of Properties | property							1
Number of Buildings							1
Square Footage | ft²							56,219
Disposed of by Sale | Downtown Austin portfolio
Real Estate Properties [Line Items]
Number of Properties | property							2
Number of Buildings							2
Square Footage | ft²							115,540
Gross Sales Price | $							$ 32,600
Gain (Loss) on Sale | $							$ 20,584
Disposed of by Sale | 785 Schilinger Road South
Real Estate Properties [Line Items]
Number of Properties | property						1
Number of Buildings						1
Square Footage | ft²						72,000
Disposed of by Sale | 401 Vine Street
Real Estate Properties [Line Items]
Number of Properties | property						1
Number of Buildings						1
Square Footage | ft²						53,980
Disposed of by Sale | 633 Frazier Drive
Real Estate Properties [Line Items]
Number of Properties | property						1
Number of Buildings						1
Square Footage | ft²						150,000
Disposed of by Sale | 9840 Gateway Boulevard North
Real Estate Properties [Line Items]
Number of Properties | property						1
Number of Buildings						1
Square Footage | ft²						72,000
Disposed of by Sale | 3003 South Expressway 281
Real Estate Properties [Line Items]
Number of Properties | property						1
Number of Buildings						1
Square Footage | ft²						150,000
Disposed of by Sale | 1331 North Center Parkway
Real Estate Properties [Line Items]
Number of Properties | property						1
Number of Buildings						1
Square Footage | ft²						53,980
Disposed of by Sale | Movie theater portfolio
Real Estate Properties [Line Items]
Number of Properties | property						6
Number of Buildings						6
Square Footage | ft²						551,960
Gross Sales Price | $						$ 109,100
Gain (Loss) on Sale | $						$ 30,595
Disposed of by Sale | 128 Crews Drive
Real Estate Properties [Line Items]
Number of Properties | property					1
Number of Buildings					1
Square Footage | ft²					185,600
Disposed of by Sale | 111 Southchase Boulevard
Real Estate Properties [Line Items]
Number of Properties | property					1
Number of Buildings					1
Square Footage | ft²					168,087
Disposed of by Sale | 1043 Global Avenue
Real Estate Properties [Line Items]
Number of Properties | property					1
Number of Buildings					1
Square Footage | ft²					450,000
Disposed of by Sale | South Carolina industrial portfolio
Real Estate Properties [Line Items]
Number of Properties | property					3
Number of Buildings					3
Square Footage | ft²					803,687
Gross Sales Price | $					$ 30,000
Gain (Loss) on Sale | $					$ 7,248
Disposed of by Sale | 100 East Wisconsin Avenue
Real Estate Properties [Line Items]
Number of Properties | property				1
Number of Buildings				1
Square Footage | ft²				435,067
Disposed of by Sale | 111 Monument Circle
Real Estate Properties [Line Items]
Number of Properties | property				1
Number of Buildings				2
Square Footage | ft²				1,121,764
Disposed of by Sale | 101-115 W. Washington Street
Real Estate Properties [Line Items]
Number of Properties | property				1
Number of Buildings				1
Square Footage | ft²				634,058
Disposed of by Sale | North Point Office Complex
Real Estate Properties [Line Items]
Number of Properties | property				1
Number of Buildings				2
Square Footage | ft²				873,335
Disposed of by Sale | Midwest portfolio
Real Estate Properties [Line Items]
Number of Properties | property				4
Number of Buildings				6
Square Footage | ft²				3,064,224
Gross Sales Price | $				$ 416,900
Gain (Loss) on Sale | $				$ (15,800)
Disposed of by Sale | 11350 North Meridian Street
Real Estate Properties [Line Items]
Number of Properties | property																			1
Number of Buildings																			1
Square Footage | ft²																			72,264
Gross Sales Price | $																			$ 4,200
Gain (Loss) on Sale | $																			$ 766
Disposed of by Sale | 333 Laurel Oak Drive
Real Estate Properties [Line Items]
Number of Properties | property																		0
Number of Buildings																2		1				3
Square Footage | ft²																		27,164
Gross Sales Price | $																		$ 2,450
Gain (Loss) on Sale | $																		$ 251
Disposed of by Sale | 1921 E. Alton Avenue
Real Estate Properties [Line Items]
Number of Properties | property																		1
Number of Buildings																		1
Square Footage | ft²																		67,846
Gross Sales Price | $																		$ 14,533
Gain (Loss) on Sale | $																		$ 4,851
Disposed of by Sale | 46 Inverness Center Parkway
Real Estate Properties [Line Items]
Number of Properties | property																	0
Number of Buildings																	0
Square Footage | ft²																	0
Gross Sales Price | $																	$ 2,000
Gain (Loss) on Sale | $																	$ 1,857
Disposed of by Sale | Sorrento Valley Business Park
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															4
Square Footage | ft²															105,003
Gross Sales Price | $															$ 23,500
Gain (Loss) on Sale | $															$ 11,896
Disposed of by Sale | Illinois Center
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														2
Square Footage | ft²														2,090,162
Gross Sales Price | $														$ 376,000
Gain (Loss) on Sale | $														$ 26,956
Disposed of by Sale | 16th and Race Street
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														1
Square Footage | ft²														608,625
Gross Sales Price | $														$ 43,000
Gain (Loss) on Sale | $														$ 7,922
Disposed of by Sale | 185 Asylum Street
Real Estate Properties [Line Items]
Number of Properties | property													1
Number of Buildings													1
Square Footage | ft²													868,395
Gross Sales Price | $													$ 113,250
Gain (Loss) on Sale | $													$ 17,619
Disposed of by Sale | One South Church Avenue
Real Estate Properties [Line Items]
Number of Properties | property												1
Number of Buildings												1
Square Footage | ft²												240,811
Gross Sales Price | $												$ 32,000
Gain (Loss) on Sale | $												$ 4,282
Disposed of by Sale | 775 Ridge Lake Boulevard
Real Estate Properties [Line Items]
Number of Properties | property												1
Number of Buildings												1
Square Footage | ft²												120,678
Gross Sales Price | $												$ 16,300
Gain (Loss) on Sale | $												$ (360)
Disposed of by Sale | One Park Square
Real Estate Properties [Line Items]
Number of Properties | property												1
Number of Buildings												6
Square Footage | ft²												259,737
Gross Sales Price | $												$ 34,300
Gain (Loss) on Sale | $												$ 9,512
Disposed of by Sale | Arizona Center
Real Estate Properties [Line Items]
Number of Properties | property											1
Number of Buildings											4
Square Footage | ft²											1,070,724
Gross Sales Price | $											$ 126,000
Gain (Loss) on Sale | $											$ 22,838
Disposed of by Sale | 4 South 84th Avenue
Real Estate Properties [Line Items]
Number of Properties | property											1
Number of Buildings											1
Square Footage | ft²											236,007
Gross Sales Price | $											$ 18,000
Gain (Loss) on Sale | $											$ 8,393
Disposed of by Sale | 7450 Campus Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																77,411
Disposed of by Sale | 129 Worthington Ridge Road
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																227,500
Disposed of by Sale | 599 Research Parkway
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																48,249
Disposed of by Sale | 181 Marsh Hill Road
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																162,036
Disposed of by Sale | 101 Barnes Road
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																45,755
Disposed of by Sale | 15 Sterling Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																173,015
Disposed of by Sale | 35 Thorpe Avenue
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																79,862
Disposed of by Sale | 50 Barnes Industrial Road North
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																154,255
Disposed of by Sale | 5-9 Barnes Industrial Road
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																38,006
Disposed of by Sale | 860 North Main Street
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																31,165
Disposed of by Sale | One Barnes Industrial Road South
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																30,170
Disposed of by Sale | Village Lane
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																2
Square Footage | ft²																58,185
Disposed of by Sale | 100 Northfield Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																116,986
Disposed of by Sale | 905 Meridian Lake Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																74,652
Disposed of by Sale | 1717 Deerfield Road
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																141,186
Disposed of by Sale | 1955 West Field Court
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																59,130
Disposed of by Sale | 5015 S. Water Circle
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																113,524
Disposed of by Sale | Adams Place
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																2
Square Footage | ft²																230,259
Disposed of by Sale | Cabot Business Park
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																2
Square Footage | ft²																252,755
Disposed of by Sale | 2300 Crown Colony Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																45,974
Disposed of by Sale | Myles Standish Industrial Park
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																2
Square Footage | ft²																74,800
Disposed of by Sale | 340 Thompson Road
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																25,000
Disposed of by Sale | 100 South Charles Street
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																159,616
Disposed of by Sale | 6710 Oxon Hill
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																118,336
Disposed of by Sale | 8800 Queen Avenue South
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																280,822
Disposed of by Sale | 9800 Sherlard Parkway
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																46,765
Disposed of by Sale | Rosedale Corporate Plaza
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																3
Square Footage | ft²																149,116
Disposed of by Sale | 1000 Shelard Parkway
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																62,499
Disposed of by Sale | 525 Park Street
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																75,636
Disposed of by Sale | 1900 Meyer Drury Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																65,225
Disposed of by Sale | 131-165 West Ninth Street
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																75,517
Disposed of by Sale | 7-9 Vreeland Road
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																155,891
Disposed of by Sale | 5 Paragon Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																119,089
Disposed of by Sale | 1000 Voorhees Drive and 400 Laurel Oak Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																2
Square Footage | ft²																125,415
Disposed of by Sale | 1601 Veterans Highway
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																63,608
Disposed of by Sale | Two Corporate Center Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																291,230
Disposed of by Sale | 11311 Cornell Center Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																93,413
Disposed of by Sale | 5300 Kings Island Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																159,421
Disposed of by Sale | 3 Crown Point Court
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																73,987
Disposed of by Sale | 515 Pennsylvania Avenue
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																82,000
Disposed of by Sale | 443 Gulph Road
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																21,000
Disposed of by Sale | 4350 Northern Pike
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																503,885
Disposed of by Sale | Thunderbolt Place
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																2
Square Footage | ft²																100,505
Disposed of by Sale | 6160 Kempsville Circle
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																129,565
Disposed of by Sale | 448 Viking Drive
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																75,374
Disposed of by Sale | Portfolio of Small Office and Industrial Assets
Real Estate Properties [Line Items]
Number of Properties | property																45
Number of Buildings																53
Square Footage | ft²																5,287,790
Gross Sales Price | $																$ 376,000
Gain (Loss) on Sale | $																$ (8,160)
Disposed of by Sale | 2501 20th Place South
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															125,722
Disposed of by Sale | 420 20th Street North
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															514,893
Disposed of by Sale | Inverness Center
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															4
Square Footage | ft²															475,882
Disposed of by Sale | 701 Poydras Street
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															1,256,971
Disposed of by Sale | 300 North Greene Street
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															324,305
Disposed of by Sale | 1320 Main Street
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															334,075
Disposed of by Sale | AL, LA, NC, SC Office Portfolio
Real Estate Properties [Line Items]
Number of Properties | property															6
Number of Buildings															9
Square Footage | ft²															3,031,848
Gross Sales Price | $															$ 417,450
Gain (Loss) on Sale | $															$ 41,596
Disposed of by Sale | 12655 Olive Boulevard
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															98,588
Disposed of by Sale | 1285 Fern Ridge Parkway
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															66,510
Disposed of by Sale | St. Louis Portfolio
Real Estate Properties [Line Items]
Number of Properties | property															2
Number of Buildings															2
Square Footage | ft²															165,098
Gross Sales Price | $															$ 14,300
Gain (Loss) on Sale | $															$ (2,349)
Disposed of by Sale | 310-314 Invermay Road
Real Estate Properties [Line Items]
Number of Properties | property																	1
Number of Buildings																	1
Square Footage | ft²																	47,480
Disposed of by Sale | 253-293 George Town Road
Real Estate Properties [Line Items]
Number of Properties | property																	1
Number of Buildings																	1
Square Footage | ft²																	143,914
Disposed of by Sale | 7 Modal Crescent
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															164,160
Disposed of by Sale | 71-93 Whiteside Road
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															303,488
Disposed of by Sale | 9-13 Titanium Court
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															69,664
Disposed of by Sale | 16 Rodborough Road
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															90,525
Disposed of by Sale | 22 Rodborough Road
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															43,427
Disposed of by Sale | 127-161 Cherry Lane
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															278,570
Disposed of by Sale | 310-320 Pitt Street
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															313,865
Disposed of by Sale | 44-46 Mandarin Street
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															226,718
Disposed of by Sale | 19 Leadership Way
Real Estate Properties [Line Items]
Number of Properties | property															1
Number of Buildings															1
Square Footage | ft²															76,714
Disposed of by Sale | Australia Portfolio
Real Estate Properties [Line Items]
Number of Properties | property																					11
Number of Buildings																					11
Square Footage | ft²																					1,758,525
Gross Sales Price | $																					$ 232,955
Gain (Loss) on Sale | $																					$ (47,872)
Disposed of by Sale | Widewaters Parkway
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														8
Square Footage | ft²														514,241
Disposed of by Sale | 5062 Brittonfield Parkway
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														1
Square Footage | ft²														40,162
Disposed of by Sale | Woodcliff Drive
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														6
Square Footage | ft²														516,760
Disposed of by Sale | Interstate Place
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														2
Square Footage | ft²														61,399
Disposed of by Sale | 1000 Pittsford - Victor Road
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														1
Square Footage | ft²														73,358
Disposed of by Sale | 1200 Pittsford - Victor Road
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														1
Square Footage | ft²														18,900
Disposed of by Sale | Corporate Crossing
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														5
Square Footage | ft²														216,126
Disposed of by Sale | Canal View Boulevard
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														3
Square Footage | ft²														118,375
Disposed of by Sale | 14 Classic Street
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														1
Square Footage | ft²														37,084
Disposed of by Sale | 110 W Fayette Street
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														1
Square Footage | ft²														304,906
Disposed of by Sale | 251 Salina Meadows Parkway
Real Estate Properties [Line Items]
Number of Properties | property														1
Number of Buildings														1
Square Footage | ft²														65,617
Disposed of by Sale | Upstate New York Portfolio
Real Estate Properties [Line Items]
Number of Properties | property														11
Number of Buildings														30
Square Footage | ft²														1,966,928
Gross Sales Price | $														$ 104,625
Gain (Loss) on Sale | $														$ (12,518)
Disposed of by Sale | 9040 Roswell Road
Real Estate Properties [Line Items]
Number of Properties | property												1
Number of Buildings												1
Square Footage | ft²												178,941
Disposed of by Sale | The Exchange
Real Estate Properties [Line Items]
Number of Properties | property												1
Number of Buildings												2
Square Footage | ft²												187,632
Disposed of by Sale | 3920 Arkwright Road
Real Estate Properties [Line Items]
Number of Properties | property												1
Number of Buildings												1
Square Footage | ft²												196,156
Disposed of by Sale | 1775 West Oak Commons Court
Real Estate Properties [Line Items]
Number of Properties | property												1
Number of Buildings												1
Square Footage | ft²												79,854
Disposed of by Sale | Georgia Portfolio
Real Estate Properties [Line Items]
Number of Properties | property												4
Number of Buildings												5
Square Footage | ft²												642,583
Gross Sales Price | $												$ 48,550
Gain (Loss) on Sale | $												$ (3,059)
Foreclosure | 225 Water Street
Real Estate Properties [Line Items]
Number of Properties | property																1
Number of Buildings																1
Square Footage | ft²																318,997
Gross Sales Price | $																$ 0
Gain (Loss) on Sale | $																$ 0