Investment in Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Document Period End Date		Sep. 30, 2015
Document Fiscal Year Focus		2015
SUMMARY OF FINANCIAL POSITION:
Total Assets		$ 646,188		$ 619,068
Total Debt		405,802		394,934
Total Equity		210,407		203,085
Company's Investment		80,146		77,461
SUMMARY OF OPERATIONS:
Total Revenues		84,608	$ 78,230
Net Income (Loss)		18,062	13,976
Income (Loss) from Equity Method Investments Gross of Impairment Charges		7,088	5,343
Terminus Office Holdings [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		285,336		288,415
Total Debt		211,835		213,640
Total Equity		59,753		62,830
Company's Investment		30,814		32,323
SUMMARY OF OPERATIONS:
Total Revenues		30,144	29,354
Net Income (Loss)		1,923	314
Income (Loss) from Equity Method Investments Gross of Impairment Charges		962	134
EP I LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		83,256		85,228
Total Debt		58,030		58,029
Total Equity		24,172		26,671
Company's Investment		22,249		22,905
SUMMARY OF OPERATIONS:
Total Revenues		9,587	9,024
Net Income (Loss)		2,481	2,102
Income (Loss) from Equity Method Investments Gross of Impairment Charges		1,864	1,577
EP II LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		70,233		42,772
Total Debt		39,149		12,735
Total Equity		24,818		24,969
Company's Investment		19,834		19,905
SUMMARY OF OPERATIONS:
Net Income (Loss)		(150)
Income (Loss) from Equity Method Investments Gross of Impairment Charges		(100)
Cousins Watkins LLC [Member]
SUMMARY OF OPERATIONS:
Total Revenues		0	3,801
Net Income (Loss)		0	217
Income (Loss) from Equity Method Investments Gross of Impairment Charges		0	1,702
Charlotte Gateway Village, LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		127,373		130,272
Total Debt		22,143		35,530
Total Equity		101,339		92,808
Company's Investment		11,193		11,218
SUMMARY OF OPERATIONS:
Total Revenues		25,311	25,079
Net Income (Loss)		9,438	8,635
Income (Loss) from Equity Method Investments Gross of Impairment Charges		883	882
HICO Victory Center LP [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		12,883		10,450
Total Debt		0		0
Total Equity		12,835		10,450
Company's Investment		9,000		7,572
Temco Associates, LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		967		6,910
Total Debt		0		0
Total Equity		386		6,709
Company's Investment		1,070		3,027
SUMMARY OF OPERATIONS:
Total Revenues		9,163	793
Net Income (Loss)		2,077	157
Income (Loss) from Equity Method Investments Gross of Impairment Charges		2,244	(24)
Carolina Square Holdings LP [Member]
Schedule of Equity Method Investments [Line Items]
General Partners' Contributed Capital		1,700
Maximum Amount Available Under Construction Facility Revised		79,800
SUMMARY OF FINANCIAL POSITION:
Total Assets		9,959		0
Total Debt		0		0
Total Equity		8,178		0
Company's Investment		$ 4,778		0
SUMMARY OF OPERATIONS:
Debt Instrument, Basis Spread on Variable Rate		1.90%
Mortgage Loans on Real Estate, Final Maturity Date		May 01, 2018
Maximum Percentage Guaranteed Under Construction Loan		12.50%
CL Realty, L.L.C. [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		$ 7,550		7,264
Total Debt		0		0
Total Equity		7,389		7,042
Company's Investment		3,724		3,546
SUMMARY OF OPERATIONS:
Total Revenues		674	1,240
Net Income (Loss)		346	846
Income (Loss) from Equity Method Investments Gross of Impairment Charges		178	410
Wildwood Associates
SUMMARY OF FINANCIAL POSITION:
Total Assets		16,501		16,400
Total Debt		0		0
Total Equity		16,384		16,389
Company's Investment	[1]	(1,108)		(1,106)
SUMMARY OF OPERATIONS:
Total Revenues		0	29
Net Income (Loss)		(89)	(125)
Income (Loss) from Equity Method Investments Gross of Impairment Charges		(45)	(50)
Crawford Long CPI LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		29,900		29,946
Total Debt		74,645		75,000
Total Equity		(46,627)		(45,762)
Company's Investment	[1]	(22,216)		(21,931)
SUMMARY OF OPERATIONS:
Total Revenues		9,193	8,905
Net Income (Loss)		2,131	2,075
Income (Loss) from Equity Method Investments Gross of Impairment Charges		1,071	1,062
Other Equity Method Investee [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		1,100		1,411
Total Debt		0		0
Total Equity		880		979
Company's Investment		2		$ 2
SUMMARY OF OPERATIONS:
Total Revenues		0	5
Net Income (Loss)		(95)	(245)
Income (Loss) from Equity Method Investments Gross of Impairment Charges		$ 31	$ (350)
NR 123 Franklin LLC [Member] | Carolina Square Holdings LP [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage of Partner in Joint Venture		5000.00%
LIBOR [Member] | Carolina Square Holdings LP [Member]
SUMMARY OF OPERATIONS:
Debt Instrument, Description of Variable Rate Basis		LIBOR

[1] Negative balances are included in deferred income on the balance sheets.