Goodwill and Intangible Assets - Summary of Goodwill (Details) - USD ($) $ in Thousands  | 
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2020  | 
Sep. 30, 2019  | 
Sep. 30, 2020  | 
Sep. 30, 2019  | 
|
| Goodwill [Line Items] | ||||
| Balance at December 31, 2019 | $ 17,558 | |||
| Goodwill impairment | $ (10,748) | $ 0 | (10,748) | $ 0 | 
| Balance at September 30, 2020 | 6,810 | 6,810 | ||
| Metals Segment | ||||
| Goodwill [Line Items] | ||||
| Balance at December 31, 2019 | 16,203 | |||
| Goodwill impairment | (10,748) | |||
| Balance at September 30, 2020 | 5,455 | 5,455 | ||
| Specialty Chemicals Segment | ||||
| Goodwill [Line Items] | ||||
| Balance at December 31, 2019 | 1,355 | |||
| Goodwill impairment | 0 | |||
| Balance at September 30, 2020 | $ 1,355 | $ 1,355 | ||
| X | ||||||||||
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
  | 
| X | ||||||||||
- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  | 
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
  | 
| X | ||||||||||
- Details 
  | 
| X | ||||||||||
- Details 
  |