XML 109 R125.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Segment and Geographic Information (Details Textual) | 12 Months Ended
--- | ---
Dec. 31, 2012 Customer | Dec. 31, 2011 Customer | Dec. 31, 2010 Customer
Segment Reporting, Revenue Reconciling Item [Line Items] |  |  |
Number of customers accounting for percentage of net sales | 0 | 0 | 0
Segment And Geographic Information (Textual) [Abstract] |  |  |
Customers accounted for certain percentage in net sales | 10.00% |  |
Advanced Airlaid Materials [Member] |  |  |
Segment Reporting, Revenue Reconciling Item [Line Items] |  |  |
Number of customers accounting for percentage of net sales | 1 | 1 | 1

X
- Definition Entity wide revenue major customer threshold percentage. + References No definition available. + Details
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Namespace Prefix: | glt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of customers accounting for percentage of net sales. + References No definition available. + Details
Name: | glt_NumberOfCustomersAccountingForPercentageOfNetSales
Namespace Prefix: | glt_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | glt_SegmentAndGeographicInformationTextualAbstract
Namespace Prefix: | glt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_SegmentReportingRevenueReconcilingItemLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration