Commitments and Contingencies - Narrative (Details)
$ in Thousands
3 Months Ended 9 Months Ended
Nov. 25, 2015
USD ($)
business
store
Sep. 08, 2015
USD ($)
Property
Jun. 30, 2016
USD ($)
Property
Sep. 30, 2016
USD ($)
tenant
claim
Loss Contingencies [Line Items]        
Outstanding claims | claim       0
Total commitments       $ 58,000
Total commitments relating to future acquisitions       24,700
Funded commitments       43,600
Contingently liable amount of debt owed by tenant       $ 5,700
Number of tenants indemnified by | tenant       1
Haggen Operations Holdings, LLC        
Loss Contingencies [Line Items]        
Number of leased properties | Property   20    
Monthly lease revenue   $ 1,400    
Number of stores assumed by tenant upon settlement | store 5      
Subsidiaries        
Loss Contingencies [Line Items]        
Number of stores assumed from settlement | store 9      
Operators assigned to assumed stores | business 3      
Stores returned upon settlement | store 6      
Unsecured stipulated damages claim received $ 21,000   $ 21,000  
Properties under master lease, partially assigned | Property     4  
Properties under master lease | Property     5  
Annual reduction of rent     $ 350  
Amount in return for rent concessions     3,000  
Amount of allowed administrative claim     800  
Amount of allowed unsecured claim     2,600  
Amount of allowed unsecured claim with administrative priority     1,800  
Stipulated claims collected     2,500  
Lease termination income     $ 1,800