Debt Obligations, net (Debt Covenants) (Details)	Dec. 31, 2019
Unsecured Debt
Debt Instrument [Line Items]
Unencumbered assets to unsecured indebtedness ratio	1.2
Consolidated fixed charge coverage ratio	1.5
Secured Debt | 2016 Senior Term Loan
Debt Instrument [Line Items]
Collateral coverage ratio	1.25
Secured Debt | 2015 $350 Million Revolving Credit Facility
Debt Instrument [Line Items]
Borrowing base asset value ratio	1.5
Cash flow to fixed charges ratio	1.5