Summary of Significant Accounting Policies - Schedule of Restricted Cash and Deposits in Escrow, Classified Within Deferred Costs and Other Assets, Net (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Restricted Cash and Cash Equivalents Items [Line Items]        
Cash and cash equivalents $ 8,798 $ 10,059 $ 21,790  
Total cash, cash equivalents and restricted cash 114,707 36,898 99,435 $ 276,525
Collateral deposits        
Restricted Cash and Cash Equivalents Items [Line Items]        
Restricted cash 1,751 2,044 15,500  
Tenant improvements, repairs and leasing commissions        
Restricted Cash and Cash Equivalents Items [Line Items]        
Restricted cash 8,257 9,739 8,362  
Master Trust Release        
Restricted Cash and Cash Equivalents Items [Line Items]        
Restricted cash 85,703 14,412 12,091  
Liquidity reserve        
Restricted Cash and Cash Equivalents Items [Line Items]        
Restricted cash 5,503 0 0  
1031 Exchange proceeds, net        
Restricted Cash and Cash Equivalents Items [Line Items]        
Restricted cash 0 0 39,869  
Other        
Restricted Cash and Cash Equivalents Items [Line Items]        
Restricted cash $ 4,695 $ 644 $ 1,823