SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	$ 0
Accumulated Depreciation	538,717,000	$ 490,697,000	$ 432,579,000	$ 376,131,000
Aggregate cost for Federal Income Tax purposes	2,419,780
Real Estate Excluding Assets Held For Sale
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	189,649,000
Initial cost of Buildings Improvements and Equipment	1,556,258,000
Costs Capitalized (Disposals) Subsequent to Acquisition	394,826,000
Historical Cost of Land	189,155,000
Historical Cost of Buildings Improvements and Equipment	1,951,578,000
Total	2,140,733,000
Accumulated Depreciation	538,717,000
Total Costs, Net of Accumulated Depreciation	1,602,016,000
Forest Park, Charlotte, NC
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	1,559,000
Initial cost of Buildings Improvements and Equipment	5,672,000
Costs Capitalized (Disposals) Subsequent to Acquisition	843,000
Historical Cost of Land	1,559,000
Historical Cost of Buildings Improvements and Equipment	6,515,000
Total	8,074,000
Accumulated Depreciation	2,197,000
Total Costs, Net of Accumulated Depreciation	$ 5,877,000
Forest Park, Charlotte, NC | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Forest Park, Charlotte, NC | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Meadow Point, Chantilly, VA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 2,634,000
Initial cost of Buildings Improvements and Equipment	18,911,000
Costs Capitalized (Disposals) Subsequent to Acquisition	8,214,000
Historical Cost of Land	2,634,000
Historical Cost of Buildings Improvements and Equipment	27,125,000
Total	29,759,000
Accumulated Depreciation	14,512,000
Total Costs, Net of Accumulated Depreciation	$ 15,247,000
Meadow Point, Chantilly, VA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Meadow Point, Chantilly, VA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Timberlake, Chesterfield, MO
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 2,984,000
Initial cost of Buildings Improvements and Equipment	38,661,000
Costs Capitalized (Disposals) Subsequent to Acquisition	10,549,000
Historical Cost of Land	2,984,000
Historical Cost of Buildings Improvements and Equipment	49,210,000
Total	52,194,000
Accumulated Depreciation	23,645,000
Total Costs, Net of Accumulated Depreciation	$ 28,549,000
Timberlake, Chesterfield, MO | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Timberlake, Chesterfield, MO | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Northwest Point, Elk Grove Village, IL
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 2,914,000
Initial cost of Buildings Improvements and Equipment	26,295,000
Costs Capitalized (Disposals) Subsequent to Acquisition	12,401,000
Historical Cost of Land	2,914,000
Historical Cost of Buildings Improvements and Equipment	38,696,000
Total	41,610,000
Accumulated Depreciation	19,497,000
Total Costs, Net of Accumulated Depreciation	$ 22,113,000
Northwest Point, Elk Grove Village, IL | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Northwest Point, Elk Grove Village, IL | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Timberlake East, Chesterfield, MO
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 2,626,000
Initial cost of Buildings Improvements and Equipment	17,608,000
Costs Capitalized (Disposals) Subsequent to Acquisition	5,377,000
Historical Cost of Land	2,626,000
Historical Cost of Buildings Improvements and Equipment	22,985,000
Total	25,611,000
Accumulated Depreciation	11,052,000
Total Costs, Net of Accumulated Depreciation	$ 14,559,000
Timberlake East, Chesterfield, MO | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Timberlake East, Chesterfield, MO | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Park Ten, Houston, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 1,061,000
Initial cost of Buildings Improvements and Equipment	21,303,000
Costs Capitalized (Disposals) Subsequent to Acquisition	6,899,000
Historical Cost of Land	567,000
Historical Cost of Buildings Improvements and Equipment	28,696,000
Total	29,263,000
Accumulated Depreciation	13,225,000
Total Costs, Net of Accumulated Depreciation	$ 16,038,000
Park Ten, Houston, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Park Ten, Houston, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Addison, Addison, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 4,325,000
Initial cost of Buildings Improvements and Equipment	48,040,000
Costs Capitalized (Disposals) Subsequent to Acquisition	12,106,000
Historical Cost of Land	4,325,000
Historical Cost of Buildings Improvements and Equipment	60,146,000
Total	64,471,000
Accumulated Depreciation	23,625,000
Total Costs, Net of Accumulated Depreciation	$ 40,846,000
Addison, Addison, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Addison, Addison, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Collins, Richardson, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 4,000,000
Initial cost of Buildings Improvements and Equipment	42,598,000
Costs Capitalized (Disposals) Subsequent to Acquisition	8,497,000
Historical Cost of Land	4,000,000
Historical Cost of Buildings Improvements and Equipment	51,095,000
Total	55,095,000
Accumulated Depreciation	23,307,000
Total Costs, Net of Accumulated Depreciation	$ 31,788,000
Collins, Richardson, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Collins, Richardson, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Greenwood, Englewood, CO
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 3,100,000
Initial cost of Buildings Improvements and Equipment	30,201,000
Costs Capitalized (Disposals) Subsequent to Acquisition	11,770,000
Historical Cost of Land	3,100,000
Historical Cost of Buildings Improvements and Equipment	41,971,000
Total	45,071,000
Accumulated Depreciation	18,663,000
Total Costs, Net of Accumulated Depreciation	$ 26,408,000
Greenwood, Englewood, CO | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Greenwood, Englewood, CO | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
River Crossing, Indianapolis, IN
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 3,000,000
Initial cost of Buildings Improvements and Equipment	36,926,000
Costs Capitalized (Disposals) Subsequent to Acquisition	6,448,000
Historical Cost of Land	3,000,000
Historical Cost of Buildings Improvements and Equipment	43,374,000
Total	46,374,000
Accumulated Depreciation	16,740,000
Total Costs, Net of Accumulated Depreciation	$ 29,634,000
River Crossing, Indianapolis, IN | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
River Crossing, Indianapolis, IN | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Innsbrook, Glenn Allen, VA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 5,000,000
Initial cost of Buildings Improvements and Equipment	40,216,000
Costs Capitalized (Disposals) Subsequent to Acquisition	8,945,000
Historical Cost of Land	5,000,000
Historical Cost of Buildings Improvements and Equipment	49,161,000
Total	54,161,000
Accumulated Depreciation	19,141,000
Total Costs, Net of Accumulated Depreciation	$ 35,020,000
Innsbrook, Glenn Allen, VA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Innsbrook, Glenn Allen, VA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
380 Interlocken, Bloomfield, CO
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 8,275,000
Initial cost of Buildings Improvements and Equipment	34,462,000
Costs Capitalized (Disposals) Subsequent to Acquisition	12,624,000
Historical Cost of Land	8,275,000
Historical Cost of Buildings Improvements and Equipment	47,086,000
Total	55,361,000
Accumulated Depreciation	17,122,000
Total Costs, Net of Accumulated Depreciation	$ 38,239,000
380 Interlocken, Bloomfield, CO | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
380 Interlocken, Bloomfield, CO | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Blue Lagoon, Miami, FL
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 6,306,000
Initial cost of Buildings Improvements and Equipment	46,124,000
Costs Capitalized (Disposals) Subsequent to Acquisition	18,068,000
Historical Cost of Land	6,306,000
Historical Cost of Buildings Improvements and Equipment	64,192,000
Total	70,498,000
Accumulated Depreciation	14,998,000
Total Costs, Net of Accumulated Depreciation	$ 55,500,000
Blue Lagoon, Miami, FL | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Blue Lagoon, Miami, FL | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Eldridge Green, Houston, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 3,900,000
Initial cost of Buildings Improvements and Equipment	43,791,000
Costs Capitalized (Disposals) Subsequent to Acquisition	5,548,000
Historical Cost of Land	3,900,000
Historical Cost of Buildings Improvements and Equipment	49,339,000
Total	53,239,000
Accumulated Depreciation	19,925,000
Total Costs, Net of Accumulated Depreciation	$ 33,314,000
Eldridge Green, Houston, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Eldridge Green, Houston, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Liberty Plaza, Addison, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 4,374,000
Initial cost of Buildings Improvements and Equipment	21,146,000
Costs Capitalized (Disposals) Subsequent to Acquisition	8,976,000
Historical Cost of Land	4,374,000
Historical Cost of Buildings Improvements and Equipment	30,122,000
Total	34,496,000
Accumulated Depreciation	12,090,000
Total Costs, Net of Accumulated Depreciation	$ 22,406,000
Liberty Plaza, Addison, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Liberty Plaza, Addison, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
One Overton, Atlanta, GA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 3,900,000
Initial cost of Buildings Improvements and Equipment	77,229,000
Costs Capitalized (Disposals) Subsequent to Acquisition	17,781,000
Historical Cost of Land	3,900,000
Historical Cost of Buildings Improvements and Equipment	95,010,000
Total	98,910,000
Accumulated Depreciation	37,025,000
Total Costs, Net of Accumulated Depreciation	$ 61,885,000
One Overton, Atlanta, GA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
One Overton, Atlanta, GA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
FSP 390 Interlocken, Broomfield, CO
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 7,013,000
Initial cost of Buildings Improvements and Equipment	37,751,000
Costs Capitalized (Disposals) Subsequent to Acquisition	14,197,000
Historical Cost of Land	7,013,000
Historical Cost of Buildings Improvements and Equipment	51,948,000
Total	58,961,000
Accumulated Depreciation	18,480,000
Total Costs, Net of Accumulated Depreciation	$ 40,481,000
FSP 390 Interlocken, Broomfield, CO | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
FSP 390 Interlocken, Broomfield, CO | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Park Ten II, Houston, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 1,300,000
Initial cost of Buildings Improvements and Equipment	31,712,000
Costs Capitalized (Disposals) Subsequent to Acquisition	6,979,000
Historical Cost of Land	1,300,000
Historical Cost of Buildings Improvements and Equipment	38,691,000
Total	39,991,000
Accumulated Depreciation	11,764,000
Total Costs, Net of Accumulated Depreciation	$ 28,227,000
Park Ten II, Houston, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Park Ten II, Houston, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Dulles Virginia, Sterling, VA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 4,813,000
Initial cost of Buildings Improvements and Equipment	13,285,000
Costs Capitalized (Disposals) Subsequent to Acquisition	6,714,000
Historical Cost of Land	4,813,000
Historical Cost of Buildings Improvements and Equipment	19,999,000
Total	24,812,000
Accumulated Depreciation	7,295,000
Total Costs, Net of Accumulated Depreciation	$ 17,517,000
Dulles Virginia, Sterling, VA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Dulles Virginia, Sterling, VA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Stonecroft, Chantilly, VA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 2,102,000
Initial cost of Buildings Improvements and Equipment	18,003,000
Costs Capitalized (Disposals) Subsequent to Acquisition	1,814,000
Historical Cost of Land	2,102,000
Historical Cost of Buildings Improvements and Equipment	19,817,000
Total	21,919,000
Accumulated Depreciation	5,116,000
Total Costs, Net of Accumulated Depreciation	$ 16,803,000
Stonecroft, Chantilly, VA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Stonecroft, Chantilly, VA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
121 South Eight Street, Minneapolis, MN
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 4,444,000
Initial cost of Buildings Improvements and Equipment	15,214,000
Costs Capitalized (Disposals) Subsequent to Acquisition	24,592,000
Historical Cost of Land	4,444,000
Historical Cost of Buildings Improvements and Equipment	39,806,000
Total	44,250,000
Accumulated Depreciation	10,917,000
Total Costs, Net of Accumulated Depreciation	$ 33,333,000
121 South Eight Street, Minneapolis, MN | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
121 South Eight Street, Minneapolis, MN | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
801 Marquette Avenue South, Minneapolis, MN
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 4,184,000
Costs Capitalized (Disposals) Subsequent to Acquisition	22,295,000
Historical Cost of Land	4,184,000
Historical Cost of Buildings Improvements and Equipment	22,295,000
Total	26,479,000
Accumulated Depreciation	1,836,000
Total Costs, Net of Accumulated Depreciation	$ 24,643,000
801 Marquette Avenue South, Minneapolis, MN | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
801 Marquette Avenue South, Minneapolis, MN | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
909 Davis, Evanston, IL
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 4,912,000
Initial cost of Buildings Improvements and Equipment	18,229,000
Costs Capitalized (Disposals) Subsequent to Acquisition	8,112,000
Historical Cost of Land	4,912,000
Historical Cost of Buildings Improvements and Equipment	26,341,000
Total	31,253,000
Accumulated Depreciation	6,985,000
Total Costs, Net of Accumulated Depreciation	$ 24,268,000
909 Davis, Evanston, IL | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
909 Davis, Evanston, IL | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Legacy Tennyson Center, Plano, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 3,067,000
Initial cost of Buildings Improvements and Equipment	22,064,000
Costs Capitalized (Disposals) Subsequent to Acquisition	3,411,000
Historical Cost of Land	3,067,000
Historical Cost of Buildings Improvements and Equipment	25,475,000
Total	28,542,000
Accumulated Depreciation	6,390,000
Total Costs, Net of Accumulated Depreciation	$ 22,152,000
Legacy Tennyson Center, Plano, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Legacy Tennyson Center, Plano, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
One Legacy Circle, Plano, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 2,590,000
Initial cost of Buildings Improvements and Equipment	36,608,000
Costs Capitalized (Disposals) Subsequent to Acquisition	3,783,000
Historical Cost of Land	2,590,000
Historical Cost of Buildings Improvements and Equipment	40,391,000
Total	42,981,000
Accumulated Depreciation	10,600,000
Total Costs, Net of Accumulated Depreciation	$ 32,381,000
One Legacy Circle, Plano, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
One Legacy Circle, Plano, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
One Ravinia Drive, Atlanta, GA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 2,686,000
Initial cost of Buildings Improvements and Equipment	35,125,000
Costs Capitalized (Disposals) Subsequent to Acquisition	12,471,000
Historical Cost of Land	2,686,000
Historical Cost of Buildings Improvements and Equipment	47,596,000
Total	50,282,000
Accumulated Depreciation	10,821,000
Total Costs, Net of Accumulated Depreciation	$ 39,461,000
One Ravinia Drive, Atlanta, GA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
One Ravinia Drive, Atlanta, GA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Two Ravinia Drive, Atlanta, GA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 7,375,000
Initial cost of Buildings Improvements and Equipment	58,726,000
Costs Capitalized (Disposals) Subsequent to Acquisition	12,259,000
Historical Cost of Land	7,375,000
Historical Cost of Buildings Improvements and Equipment	70,985,000
Total	78,360,000
Accumulated Depreciation	11,630,000
Total Costs, Net of Accumulated Depreciation	$ 66,730,000
Two Ravinia Drive, Atlanta, GA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Two Ravinia Drive, Atlanta, GA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Westchase I & II, Houston, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 8,491,000
Initial cost of Buildings Improvements and Equipment	121,508,000
Costs Capitalized (Disposals) Subsequent to Acquisition	14,548,000
Historical Cost of Land	8,491,000
Historical Cost of Buildings Improvements and Equipment	136,056,000
Total	144,547,000
Accumulated Depreciation	29,975,000
Total Costs, Net of Accumulated Depreciation	$ 114,572,000
Westchase I & II, Houston, TX | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Westchase I & II, Houston, TX | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
1999 Broadway, Denver, CO
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 16,334,000
Initial cost of Buildings Improvements and Equipment	137,726,000
Costs Capitalized (Disposals) Subsequent to Acquisition	38,338,000
Historical Cost of Land	16,334,000
Historical Cost of Buildings Improvements and Equipment	176,064,000
Total	192,398,000
Accumulated Depreciation	34,199,000
Total Costs, Net of Accumulated Depreciation	$ 158,199,000
1999 Broadway, Denver, CO | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
1999 Broadway, Denver, CO | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
999 Peachtree, Atlanta, GA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 10,187,000
Initial cost of Buildings Improvements and Equipment	107,727,000
Costs Capitalized (Disposals) Subsequent to Acquisition	23,820,000
Historical Cost of Land	10,187,000
Historical Cost of Buildings Improvements and Equipment	131,547,000
Total	141,734,000
Accumulated Depreciation	25,096,000
Total Costs, Net of Accumulated Depreciation	$ 116,638,000
999 Peachtree, Atlanta, GA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
999 Peachtree, Atlanta, GA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
1001 17th Street, Denver, CO
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 17,413,000
Initial cost of Buildings Improvements and Equipment	165,058,000
Costs Capitalized (Disposals) Subsequent to Acquisition	22,284,000
Historical Cost of Land	17,413,000
Historical Cost of Buildings Improvements and Equipment	187,342,000
Total	204,755,000
Accumulated Depreciation	35,495,000
Total Costs, Net of Accumulated Depreciation	$ 169,260,000
1001 17th Street, Denver, CO | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
1001 17th Street, Denver, CO | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Plaza Seven, Minneapolis, MN
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 6,604,000
Initial cost of Buildings Improvements and Equipment	54,240,000
Costs Capitalized (Disposals) Subsequent to Acquisition	11,073,000
Historical Cost of Land	6,604,000
Historical Cost of Buildings Improvements and Equipment	65,313,000
Total	71,917,000
Accumulated Depreciation	9,175,000
Total Costs, Net of Accumulated Depreciation	$ 62,742,000
Plaza Seven, Minneapolis, MN | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Plaza Seven, Minneapolis, MN | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
Pershing Plaza, Atlanta, GA
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 5,300,000
Initial cost of Buildings Improvements and Equipment	34,158,000
Costs Capitalized (Disposals) Subsequent to Acquisition	2,040,000
Historical Cost of Land	5,300,000
Historical Cost of Buildings Improvements and Equipment	36,198,000
Total	41,498,000
Accumulated Depreciation	4,110,000
Total Costs, Net of Accumulated Depreciation	$ 37,388,000
Pershing Plaza, Atlanta, GA | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
Pershing Plaza, Atlanta, GA | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years
600 17th Street, Denver, Co
REAL ESTATE AND ACCUMULATED DEPRECIATION
Initial cost of Land	$ 20,876,000
Initial cost of Buildings Improvements and Equipment	99,941,000
Costs Capitalized (Disposals) Subsequent to Acquisition	11,050,000
Historical Cost of Land	20,876,000
Historical Cost of Buildings Improvements and Equipment	110,991,000
Total	131,867,000
Accumulated Depreciation	12,069,000
Total Costs, Net of Accumulated Depreciation	$ 119,798,000
600 17th Street, Denver, Co | Minimum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	5 years
600 17th Street, Denver, Co | Maximum
REAL ESTATE AND ACCUMULATED DEPRECIATION
Depreciable Life Years	39 years