Commitments and Contingencies - Narrative (Details)
$ in Millions
9 Months Ended
Sep. 30, 2015
USD ($)
Property
tenant
claim
Loss Contingencies [Line Items]  
Outstanding claims | claim 0
Total commitments $ 186.7
Total commitments relating to future acquisitions 180.6
Contingently liable amount of debt owed by tenant $ 5.7
Number of tenants indemnified by | tenant 1
Haggen Operations Holdings, LLC  
Loss Contingencies [Line Items]  
Number of leased properties | Property 20
Monthly lease revenue $ 1.4