Variable Interest Entities (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 Entity Investment Asset
Variable Interest Entities (Textual) [Abstract]
Variable interest entity ownership percentage	100.00%
Gain or loss in connection with the acquisition and consolidation of the property	$ 0
Identified investments	11
Investments with no equity at risk	7
Number of assets identified as variable interests in variable interest entities	6
Number of additional entities	4
Cerritos [Member]
Variable Interest Entity [Line Items]
Land and building	21,423,000
Net of accumulated depreciation	157,000
Cerritos [Member] | Mortgage debt A-Note [Member]
Variable Interest Entity [Line Items]
Mortgage debt	23,184,000
Cerritos [Member] | Mortgage debt B-Note [Member]
Variable Interest Entity [Line Items]
Mortgage debt	$ 876,000