Investment in Unconsolidated Joint Ventures (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013		Jun. 30, 2013		Jun. 30, 2012		Dec. 31, 2012
SUMMARY OF FINANCIAL POSITION:
Total Assets	$ 1,145,968,000		$ 1,145,968,000				$ 950,013,000
Total Debt	562,920,000		562,920,000				390,794,000
Total Equity	551,126,000		551,126,000				535,515,000
Company's Investment	105,941,000		105,941,000				89,797,000
SUMMARY OF OPERATIONS:
Total Revenues			77,469,000		76,266,000
Net Income (Loss)			12,879,000		36,246,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			2,784,000		11,948,000
MSREF Terminus Two Hundred LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	0	[1]	0	[1]			95,520,000	[1]
Total Debt	0	[1]	0	[1]			74,340,000	[1]
Total Equity	0	[1]	0	[1]			19,659,000	[1]
Company's Investment	0	[1]	0	[1]			3,930,000	[1]
SUMMARY OF OPERATIONS:
Total Revenues			1,278,000	[1]	6,105,000	[1]
Net Income (Loss)			(161,000)	[1]	(704,000)	[1]
Income (Loss) from Equity Method Investments Gross of Impairment Charges			(28,000)	[1]	(141,000)	[1]
EP I LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	89,604,000		89,604,000				83,235,000
Total Debt	55,482,000		55,482,000				43,515,000
Total Equity	31,902,000		31,902,000				32,611,000
Company's Investment	27,321,000		27,321,000				27,864,000
SUMMARY OF OPERATIONS:
Total Revenues			2,988,000		110,000
Net Income (Loss)			(695,000)		(1,000)
Income (Loss) from Equity Method Investments Gross of Impairment Charges			(521,000)		(1,000)
Cousins Watkins LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	53,133,000		53,133,000				54,285,000
Total Debt	27,990,000		27,990,000				28,244,000
Total Equity	24,206,000		24,206,000				25,259,000
Company's Investment	16,944,000		16,944,000				16,692,000
SUMMARY OF OPERATIONS:
Total Revenues			2,595,000		3,120,000
Net Income (Loss)			46,000		(18,000)
Income (Loss) from Equity Method Investments Gross of Impairment Charges			1,159,000		1,219,000
CF Murfreesboro Associates [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	118,167,000		118,167,000				121,451,000
Total Debt	91,854,000		91,854,000				94,540,000
Total Equity	24,878,000		24,878,000				25,411,000
Company's Investment	14,283,000		14,283,000				14,571,000
SUMMARY OF OPERATIONS:
Total Revenues			6,576,000		6,612,000
Net Income (Loss)			(507,000)		138,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			(379,000)		(66,000)
CP Venture Five LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	281,447,000		281,447,000				286,647,000
Total Debt	35,096,000		35,096,000				35,417,000
Total Equity	238,305,000		238,305,000				243,563,000
Company's Investment	13,584,000		13,584,000				13,884,000
SUMMARY OF OPERATIONS:
Total Revenues			15,140,000		15,097,000
Net Income (Loss)			2,193,000		1,758,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			558,000		508,000
Charlotte Gateway Village, LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	138,078,000		138,078,000				140,384,000
Total Debt	60,452,000		60,452,000				68,242,000
Total Equity	75,536,000		75,536,000				70,917,000
Company's Investment	10,282,000		10,282,000				10,299,000
SUMMARY OF OPERATIONS:
Total Revenues			16,815,000		16,477,000
Net Income (Loss)			5,224,000		4,733,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			588,000		588,000
Temco Associates, LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	8,547,000		8,547,000				8,409,000
Total Debt	0		0				0
Total Equity	8,224,000		8,224,000				8,233,000
Company's Investment	4,079,000		4,079,000				4,095,000
SUMMARY OF OPERATIONS:
Total Revenues			206,000		500,000
Net Income (Loss)			18,000		(123,000)
Income (Loss) from Equity Method Investments Gross of Impairment Charges			(15,000)		(265,000)
CL Realty, L.L.C. [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	7,797,000		7,797,000				7,549,000
Total Debt	0		0				0
Total Equity	7,598,000		7,598,000				7,155,000
Company's Investment	3,786,000		3,786,000				3,579,000
SUMMARY OF OPERATIONS:
Total Revenues			373,000		1,997,000
Net Income (Loss)			216,000		736,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			206,000		53,000
CP Venture Two LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	93,518,000		93,518,000				96,345,000
Total Debt	0		0				0
Total Equity	92,103,000		92,103,000				94,819,000
Company's Investment	2,614,000		2,614,000				2,894,000
SUMMARY OF OPERATIONS:
Total Revenues			9,741,000		9,695,000
Net Income (Loss)			5,386,000		4,898,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			556,000		507,000
Wildwood Associates [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	21,157,000		21,157,000				21,176,000
Total Debt	0		0				0
Total Equity	21,088,000		21,088,000				21,173,000
Company's Investment	(1,705,000)	[2]	(1,705,000)	[2]			(1,664,000)	[2]
SUMMARY OF OPERATIONS:
Total Revenues			0		0
Net Income (Loss)			(84,000)		(81,000)
Income (Loss) from Equity Method Investments Gross of Impairment Charges			(42,000)		(40,000)
Crawford Long - CPI, LLC [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	34,133,000		34,133,000				32,818,000
Total Debt	75,000,000		75,000,000				46,496,000
Total Equity	(42,832,000)		(42,832,000)				(15,129,000)
Company's Investment	(20,302,000)	[2]	(20,302,000)	[2]			(6,407,000)	[2]
SUMMARY OF OPERATIONS:
Total Revenues			5,873,000		5,850,000
Net Income (Loss)			1,382,000		1,247,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			686,000		620,000
Debt face amount	75,000,000		75,000,000
Debt interest rate (percent)	3.50%		3.50%
Proceeds from Issuance of Long-term Debt	14,300,000
Terminus Office Holdings [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	298,241,000	[1]	298,241,000	[1]			0	[1]
Total Debt	217,046,000	[1]	217,046,000	[1]			0	[1]
Total Equity	68,280,000	[1]	68,280,000	[1]			0	[1]
Company's Investment	34,992,000	[1]	34,992,000	[1]			0	[1]
SUMMARY OF OPERATIONS:
Total Revenues			14,616,000	[1]	0	[1]
Net Income (Loss)			29,000	[1]	0	[1]
Income (Loss) from Equity Method Investments Gross of Impairment Charges			14,000	[1]	0	[1]
Palisades West LLC [Member]
SUMMARY OF OPERATIONS:
Total Revenues			0		8,192,000
Net Income (Loss)			(28,000)		2,885,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			0		1,381,000
Ten Peachtree Place Associates [Member]
SUMMARY OF OPERATIONS:
Total Revenues			0		2,487,000
Net Income (Loss)			0		20,897,000
Income (Loss) from Equity Method Investments Gross of Impairment Charges			0		7,831,000
Other Equity Method Investee [Member]
SUMMARY OF FINANCIAL POSITION:
Total Assets	2,146,000		2,146,000				2,194,000
Total Debt	0		0				0
Total Equity	1,838,000		1,838,000				1,844,000
Company's Investment	63,000		63,000				60,000
SUMMARY OF OPERATIONS:
Total Revenues			1,268,000		24,000
Net Income (Loss)			(140,000)		(119,000)
Income (Loss) from Equity Method Investments Gross of Impairment Charges			$ 2,000		$ (246,000)

[1] See note 7 for further discussion of the transactions affecting these entities.

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