Investments in Real Estate and Real Estate Under Construction (Details) (USD $)	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011	Dec. 31, 2011
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	$ 104,328,000
Land	23,030,000
Building and Improvements	66,964,000
Lease in-place Value	11,499,000
Tenant Relationships Value	2,835,000
Leasing costs incurred	488,000
Aggregate aquisition expenses	786,000		314,000
Development in Process	41,676,000			34,529,000
Development Deals [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Real Estate Investment Capitalized Interest	1,693,000		882,000
Payment Guarantee [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Guarantor Obligations, Current Carrying Value	1,500,000
Corporate Joint Venture [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Maximum Loan to Joint Venture	4,398,000
Lender Subsidiary [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Square Feet	1,251,000
Expected Maximum Commitment/Contribution	152,900,000
Estimated Property Purchase Price/Completion Cost	161,700,000
Office Property [Member] | Huntington West Virginia [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	12,558,000
Land	1,368,000
Building and Improvements	9,527,000
Lease in-place Value	1,405,000
Tenant Relationships Value	258,000
Office Property [Member] | Florence South Carolina [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	5,094,000
Land	774,000
Building and Improvements	3,629,000
Lease in-place Value	505,000
Tenant Relationships Value	186,000
Office Property [Member] | Saint Joseph Missouri [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	17,571,000
Land	607,000
Building and Improvements	14,004,000
Lease in-place Value	2,528,000
Tenant Relationships Value	432,000
Office Property [Member] | Jessup Pennsylvania [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	24,917,000
Land	2,520,000
Building and Improvements	17,656,000
Lease in-place Value	3,336,000
Tenant Relationships Value	1,405,000
Office Property [Member] | Eugene Oregon [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Square Feet	80,000
Expected Maximum Commitment/Contribution	17,600,000
Estimated Property Purchase Price/Completion Cost	17,600,000
Lease Term (Years)	15
Office Property [Member] | Denver Colorado [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Square Feet	163,000
Expected Maximum Commitment/Contribution	37,600,000
Estimated Property Purchase Price/Completion Cost	37,600,000
Lease Term (Years)	15
Industrial Property [Member] | Missouri City Texas [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	23,000,000
Land	14,555,000
Building and Improvements	5,895,000
Lease in-place Value	2,135,000
Tenant Relationships Value	415,000
Industrial Property [Member] | Shreveport Louisiana [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	12,941,000
Land	1,078,000
Building and Improvements	10,134,000
Lease in-place Value	1,590,000
Tenant Relationships Value	139,000
Industrial Property [Member] | Long Island City New York [Member] | Corporate Joint Venture [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Square Feet	143,000	[1]
Expected Maximum Commitment/Contribution	46,700,000	[1]
Estimated Property Purchase Price/Completion Cost	55,500,000	[1]
Lease Term (Years)	15	[1]
Industrial Property [Member] | Rantoul Illinois [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Square Feet	813,000	[2]
Expected Maximum Commitment/Contribution	42,600,000	[2]
Estimated Property Purchase Price/Completion Cost	42,600,000	[2]
Lease Term (Years)	20	[2]
Retail Property [Member] | Valdosta Georgia [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Initial Cost Basis	8,247,000	[3]
Land	2,128,000	[3]
Building and Improvements	6,119,000	[3]
Lease in-place Value	0	[3]
Tenant Relationships Value	0	[3]
Retail Property [Member] | Opelika Alabama [Member]
Investments in Real Estate and Real Estate Under Construction [Line Items]
Square Feet	52,000
Expected Maximum Commitment/Contribution	8,400,000
Estimated Property Purchase Price/Completion Cost	$ 8,400,000
Lease Term (Years)	15

[1] Joint venture investment. The Company has guaranteed completion to the ground owner. The guarantee obligation was valued at $1,500 and is included in accounts payable and other liabilities in the condensed consolidated balance sheets as of September 30, 2012 and December 31, 2011. In addition, the Company may loan a maximum of $4,398 to the joint venture under certain circumstances. The difference between the Company's expected contribution and the estimated completion cost represents the joint venture partner's equity.

[2] Acquisition, development and construction arrangement.

[3] Incurred leasing costs of $488.