Discontinued Operations - Discontinued Operation, Statements of Cash Flows Disclosures (Details) - Spirit MTA REIT - Spinoff - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Net cash provided by operating activities $ 36,589 $ 79,950
Net cash (used in) provided by investing activities $ (31,452) $ 74,130