Accounting Policies (Details Textuals) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015
Variable Interest Entity [Line Items]
Maximum loss exposure for unconsolidated variable interest entities	$ 325
Primary beneficiary [Member]
Variable Interest Entity [Line Items]
Number of variable interest entities	24
Number of properties represented by variable interest entities	21
Not primary beneficiary [Member]
Variable Interest Entity [Line Items]
Number of variable interest entities	66