Discontinued Operations - Discontinued Operations, Statement of Cash Flows Disclosure (Details) - Spirit MTA REIT - Spinoff - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Net cash provided by operating activities $ 144 $ 160 $ 173
Net cash provided by investing activities $ 136 $ 100 $ 262