Discontinued Operations - Narrative (Details) - Spirit MTA REIT - Spinoff - USD ($)
$ in Millions
1 Months Ended
May 31, 2018
Jun. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Reduction in goodwill as a result of the Spin-Off $ 28.7  
Cash inflows from continuing involvement subsequent to spin-off   $ 9.6
Cash outflows from continuing involvement subsequent to spin-off   $ 7.1