XML 35 R26.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Segment information - Narrative (Details) | 6 Months Ended
--- | ---
Jun. 30, 2018 segment
Operating Segments [Abstract] |
Number of operating segments | 2

X
- Definition Number Of Operating Segments1 + References No definition available. + Details
Name: | oec_NumberOfOperatingSegments1
Namespace Prefix: | oec_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Operating Segments [Abstract] + References No definition available. + Details
Name: | oec_OperatingSegmentsAbstract
Namespace Prefix: | oec_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration