XML 45 R31.htm IDEA: XBRL DOCUMENT
v3.21.1

Discontinued Operations (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2021
Discontinued Operations And Disposal Groups [Abstract] |
Summary of Cash Flows from Discontinued Operations Included in Condensed Consolidated Statements of Cash Flows | The following table sets forth a summary of cash flows from discontinued operations which is included in the condensed consolidated statements of cash flows:
|  | Three months ended March 31 |  |
In thousands |  | 2021 |  |  | 2020 |  |
Net cash used by operating activities |  | $ | (78 | ) |  | $ | (316 | ) |
Net cash used by investing activities |  |  | — |  |  |  | — |  |
Net cash provided by financing activities |  |  | — |  |  |  | — |  |
Change in cash and cash equivalents from discontinued operations |  | $ | (78 | ) |  | $ | (316 | ) |

X
- Definition Schedule of disposal groups including discontinued operations cash flow. + References No definition available. + Details
Name: | glt_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsCashFlowTextBlock
Namespace Prefix: | glt_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration