Investment in Unconsolidated Joint Ventures (CP Venture Two LLC) (Details) (CP Venture Two LLC [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	10.40%
Company's share of gain on sale of equity investee property	$ 167
Retail [Member]
Schedule of Equity Method Investments [Line Items]
Number of real estate properties owned by venture (properties)	3
Square footage of real estate property (square feet)	934,000
Office Building [Member]
Schedule of Equity Method Investments [Line Items]
Square footage of real estate property (square feet)	69,000