Commitments and Contingencies - Additional Information (Details)
1 Months Ended 12 Months Ended 36 Months Ended
Dec. 31, 2018
USD ($)
ground_lease
tenant
claim
Dec. 31, 2018
USD ($)
ground_lease
tenant
claim
renewal_option
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Property
Dec. 31, 2017
USD ($)
Loss Contingencies [Line Items]            
Number of outstanding claims | claim 0 0        
Total commitments $ 80,700,000 $ 80,700,000        
Total commitments relating to future acquisitions 47,700,000 47,700,000        
Commitments to purchase capital assets within one year expected to be funded within one year $ 79,300,000 79,300,000        
Contingently liable amount of debt owed by tenant   $ 5,700,000        
Number of tenants indemnified by for any payments the Company may be required to make on debt | tenant 1 1        
Accruals made for environmental remediation $ 0 $ 0        
Operating lease number of renewal options | renewal_option   2        
Operating lease renewal term 5 years 5 years        
Number of properties subject to ground leases | ground_lease 7 7        
General and Administrative Expense            
Loss Contingencies [Line Items]            
Rental expense   $ 900,000 $ 900,000 $ 1,500,000    
Property Costs            
Loss Contingencies [Line Items]            
Rental expense   900,000 $ 1,500,000 1,400,000    
Albertons, LLC            
Loss Contingencies [Line Items]            
Amount of bankruptcy claims settled       3,000,000    
Haggen Operations Holdings, LLC            
Loss Contingencies [Line Items]            
Amount of bankruptcy claims settled       $ 3,400,000    
Spirit Realty, L.P.            
Loss Contingencies [Line Items]            
Other expense   $ 5,300,000        
Subsidiaries | Haggen Operations Holdings, LLC            
Loss Contingencies [Line Items]            
Properties leased | Property         20  
Spirit Realty, Inc. | Haggen Operations Holdings, LLC            
Loss Contingencies [Line Items]            
Initial litigation settlement         $ 21,000,000  
Haggen Operations Holdings, LLC Bankruptcy Claim            
Loss Contingencies [Line Items]            
Settlement proceeds $ 19,700,000         $ 5,500,000
Proceeds from settlements used to relieve accruals 600,000          
Haggen Operations Holdings, LLC Bankruptcy Claim | Other income            
Loss Contingencies [Line Items]            
Settlement proceeds $ 19,100,000