Derivative and Hedging Activities - Summary of Notional Amount and Fair Value of Derivative Instruments (Footnote) (Details) - Jun. 30, 2015
USD ($)
loan
Derivative
USD ($)
Derivative
USD ($)
Derivative
Derivatives, Fair Value [Line Items]      
Loss recognized on termination of interest rate swap agreements   $ 76,000 $ 76,000
Interest Rate Swap      
Derivatives, Fair Value [Line Items]      
Payments to terminate interest rate swap agreements $ 100,000    
Loss recognized on termination of interest rate swap agreements $ 100,000    
Derivative Instrument 4 | Designated as Hedging Instrument | Accounts payable, accrued expenses and other liabilities | Interest Rate Swap      
Derivatives, Fair Value [Line Items]      
Number of interest rate derivatives held | Derivative 8 8 8
Notional amount $ 61,758,000 $ 61,758,000 $ 61,758,000
Derivative Instrument 4 | Designated as Hedging Instrument | Accounts payable, accrued expenses and other liabilities | Interest Rate Swap | Minimum      
Derivatives, Fair Value [Line Items]      
Notional amount 7,600,000 7,600,000 7,600,000
Derivative Instrument 4 | Designated as Hedging Instrument | Accounts payable, accrued expenses and other liabilities | Interest Rate Swap | Maximum      
Derivatives, Fair Value [Line Items]      
Notional amount $ 7,900,000 $ 7,900,000 $ 7,900,000
CMBS Loans      
Derivatives, Fair Value [Line Items]      
Number of loans repaid | loan 2