Long-Term Incentive Plan Units (Narrative) (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Mar. 07, 2018 |
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Common Stock, Capital Shares Reserved for Future Issuance | 1,906,046 | 1,906,046 | |||
| Share-based long term incentive plan unit expense | $ 99 | $ 95 | $ 192 | $ 189 | |
| Long-Term Incentive Plan Units [Member] | |||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| LTIP Unit Grants in Period | 0 | 0 | 1,723 | 0 | |
| Dedicated or partially dedicated personnel [Member] | Long-Term Incentive Plan Units [Member] | |||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| LTIP Unit Grants in Period | 1,723 | ||||