Investment in Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Document Period End Date		Jun. 30, 2015
Document Fiscal Year Focus		2015
SUMMARY OF FINANCIAL POSITION:
Total Assets		$ 648,686		$ 619,068
Total Debt		405,028		394,934
Total Equity		191,885		203,085
Company's Investment		80,807		77,461
SUMMARY OF OPERATIONS:
Total Revenues		50,533	$ 52,046
Net Income (Loss)		10,729	9,009
Income (Loss) from Equity Method Investments Gross of Impairment Charges		3,372	3,313
Terminus Office Holdings [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		291,133		288,415
Total Debt		212,444		213,640
Total Equity		64,374		62,830
Company's Investment		32,916		32,323
SUMMARY OF OPERATIONS:
Total Revenues		19,638	19,357
Net Income (Loss)		1,139	(2)
Income (Loss) from Equity Method Investments Gross of Impairment Charges		570	(23)
EP I LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		84,490		85,228
Total Debt		58,029		58,029
Total Equity		24,611		26,671
Company's Investment		22,217		22,905
SUMMARY OF OPERATIONS:
Total Revenues		6,218	5,975
Net Income (Loss)		1,480	1,417
Income (Loss) from Equity Method Investments Gross of Impairment Charges		1,112	1,062
EP II LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		65,213		42,772
Total Debt		32,879		12,735
Total Equity		24,858		24,969
Company's Investment		19,839		19,905
Cousins Watkins LLC [Member]
SUMMARY OF OPERATIONS:
Total Revenues		0	2,526
Net Income (Loss)		0	159
Income (Loss) from Equity Method Investments Gross of Impairment Charges		0	1,133
Charlotte Gateway Village, LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		127,949		130,272
Total Debt		26,676		35,530
Total Equity		87,736		92,808
Company's Investment		11,201		11,218
SUMMARY OF OPERATIONS:
Total Revenues		16,913	16,732
Net Income (Loss)		6,225	5,689
Income (Loss) from Equity Method Investments Gross of Impairment Charges		589	588
HICO Victory Center LP [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		12,458		10,450
Total Debt		0		0
Total Equity		12,204		10,450
Company's Investment		8,636		7,572
Temco Associates, LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		6,536		6,910
Total Debt		0		0
Total Equity		6,144		6,709
Company's Investment		2,769		3,027
SUMMARY OF OPERATIONS:
Total Revenues		1,144	714
Net Income (Loss)		435	114
Income (Loss) from Equity Method Investments Gross of Impairment Charges		242	(34)
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		4,960		0
Total Debt		0		0
Total Equity		4,960		0
Company's Investment		$ 2,409		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		$ 7,403		7,264
Total Debt		0		0
Total Equity		7,285		7,042
Company's Investment		3,676		3,546
SUMMARY OF OPERATIONS:
Total Revenues		469	827
Net Income (Loss)		243	550
Income (Loss) from Equity Method Investments Gross of Impairment Charges		130	264
Wildwood Associates
SUMMARY OF FINANCIAL POSITION:
Total Assets		16,440		16,400
Total Debt		0		0
Total Equity		16,402		16,389
Company's Investment	[1]	(1,136)		(1,106)
SUMMARY OF OPERATIONS:
Total Revenues		0	29
Net Income (Loss)		(58)	(86)
Income (Loss) from Equity Method Investments Gross of Impairment Charges		(30)	(30)
Crawford Long CPI LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		30,986		29,946
Total Debt		75,000		75,000
Total Equity		(57,595)		(45,762)
Company's Investment	[1]	(21,722)		(21,931)
SUMMARY OF OPERATIONS:
Total Revenues		6,139	5,881
Net Income (Loss)		1,446	1,348
Income (Loss) from Equity Method Investments Gross of Impairment Charges		728	701
Other Equity Method Investee [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets		1,118		1,411
Total Debt		0		0
Total Equity		906		979
Company's Investment		2		$ 2
SUMMARY OF OPERATIONS:
Total Revenues		12	5
Net Income (Loss)		(181)	(180)
Income (Loss) from Equity Method Investments Gross of Impairment Charges		$ 31	$ (348)
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.