Organization (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended	24 Months Ended
	Dec. 31, 2012 stockholders	Sep. 30, 2014
Organization (Textual) [Abstract]
Common Stock, Value Authorized during Offering		$ 3,000,000
Organization (Additional Textual) [Abstract]
Incorporation date	May 28, 2004
Total number of stockholders	1,949
Affiliated Entity [Member]
Organization (Textual) [Abstract]
Aggregate investment through purchases of shares of our undesignated common stock	60,200
Consolidated properties [Member]
Organization (Textual) [Abstract]
Number of properties owned	32
Number of states	9
Unconsolidated Real Estate Affiliates [Member]
Organization (Textual) [Abstract]
Number of states	1
Class A [Member]
Organization (Textual) [Abstract]
Common stock, shares outstanding	3,612,169
Class E [Member]
Organization (Textual) [Abstract]
Common stock, shares outstanding	26,444,843
Class M [Member]
Organization (Textual) [Abstract]
Common stock, shares outstanding	104,282