Segment Reporting (Narrative) (Details) |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2018
USD ($)
|
Sep. 30, 2018
USD ($)
|
Jun. 30, 2018
USD ($)
|
Mar. 31, 2018
USD ($)
|
Dec. 31, 2017
USD ($)
|
Sep. 30, 2017
USD ($)
|
Jun. 30, 2017
USD ($)
|
Mar. 31, 2017
USD ($)
|
Dec. 31, 2018
USD ($)
segment
|
Dec. 31, 2017
USD ($)
|
Dec. 31, 2016
USD ($)
|
|
| Segment Reporting Information [Line Items] | |||||||||||
| Number of business segments | segment | 2 | ||||||||||
| Total revenues | $ 132,936,000 | $ 132,114,000 | $ 126,589,000 | $ 138,967,000 | $ 143,529,000 | $ 160,018,000 | $ 162,766,000 | $ 149,887,000 | $ 530,606,000 | $ 616,200,000 | $ 613,398,000 |
| Foreign Locations [Member] | |||||||||||
| Segment Reporting Information [Line Items] | |||||||||||
| Total revenues | 0 | 0 | $ 0 | ||||||||
| Long lived assets | $ 0 | $ 0 | $ 0 | $ 0 | |||||||