Basis of Presentation (Details) $ in Millions	Sep. 30, 2015 USD ($) loan_pool Property	Dec. 31, 2014 USD ($)
Noncontrolling Interest [Line Items]
Assets	$ 7,292.7	$ 6,332.1
Properties, Loans and Servicing Platform in Europe [Member] \| Europe [Member]
Noncontrolling Interest [Line Items]
Assets	882.7
KWE [Member]
Noncontrolling Interest [Line Items]
Ordinary shares, initial public offering share subscription, cash	330.7
Ordinary shares, initial public offering share subscription, contribution of assets	$ 58.3
Ownership percentage by parent	17.70%
Properties, Loans and Servicing Platform in Europe [Member]
Noncontrolling Interest [Line Items]
Number of real estate investment properties in Europe \| Property	18
Number of loan pools \| loan_pool	4
Properties, Loans and Servicing Platform in Europe [Member] \| Europe [Member]
Noncontrolling Interest [Line Items]
Ownership percentage by parent	57.60%
Equity in consolidated investments	$ 248.0

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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