Investment in Unconsolidated Joint Ventures (CP Venture V Holdings LLC) (Details) (Cp Venture Five LLC [Member], USD $)	12 Months Ended
	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Ownership percentage equity method investment (percent)	11.50%
Number of real estate properties owned by venture (properties)	5
Square footage of real estate property (square feet)	1,200,000
Cash balance of joint venture	$ 1,200,000
Suburban Atlanta Georgia [Member]
Schedule of Equity Method Investments [Line Items]
Number of real estate properties owned by venture (properties)	3
Viera Florida [Member]
Schedule of Equity Method Investments [Line Items]
Number of real estate properties owned by venture (properties)	2
Secured Mortgage Note Payable [Member]
Schedule of Equity Method Investments [Line Items]
Outstanding amount of mortgage note payable of joint venture	$ 35,400,000
Interest rate on mortgage loan (percent)	4.52%
Amortization period for mortgage note payable of joint venture (years)	30 years
Maturity date of debt instrument	Dec. 01, 2017