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Derivatives Instruments and Hedging Activities - Additional Information (Details)
3 Months Ended
Mar. 31, 2016
USD ($)
Derivative
Mar. 31, 2015
USD ($)
Derivative [Line Items]    
Change in value of interest rate swaps $ (29,867,000)  
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]    
Derivative [Line Items]    
Number of derivatives | Derivative 14  
Aggregate notional amount $ 1,200,000,000  
Unrealized gains on interest rate swaps 6,860,000 $ 11,978,000
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Cash Flow Hedges [Member]    
Derivative [Line Items]    
Change in value of interest rate swaps $ 29,867,000  
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | 1633 Broadway [Member] | Cash Flow Hedges [Member]    
Derivative [Line Items]    
Number of derivatives | Derivative 3  
Aggregate notional amount $ 1,000,000,000  
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | 1633 Broadway [Member] | March Two Thousand Sixteen | Cash Flow Hedges [Member]    
Derivative [Line Items]    
Aggregate notional amount $ 400,000,000