Summary of Significant Accounting Policies (Details Textual 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Variable Interest Entity [Line Items]
Maximum loss exposure for unconsolidated variable interest entities	$ 62
Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Number of variable interest entities	33
Number of properties represented by variable interest entities	24
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Number of variable interest entities	59