XML 49 R59.htm IDEA: XBRL DOCUMENT v3.2.0.727

Fair Value of Financial Instruments - Carrying Value and Fair Value of Long-Term Debt (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	$ 390,711	$ 404,612
Fair Value	399,932	411,757
Variable Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	83,287	90,555
Fair Value	83,287	90,555
Fixed-Rate Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	250,000	250,000
Fair Value	257,813	255,470
2.40% Term Loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	11,179	12,155
Fair Value	11,581	12,626
2.05% Term Loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Value	46,245	51,902
Fair Value	$ 47,251	$ 53,106

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.

+ References

No definition available.

+ Details

Name:	us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 942



-SubTopic 210



-Section S99



-Paragraph 1



-Subparagraph (SX 210.9-03.16)



-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878



Reference 2: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 210



-SubTopic 10



-Section S99



-Paragraph 1



-Subparagraph (SX 210.5-02.22)



-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682



Reference 3: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 944



-SubTopic 210



-Section S99



-Paragraph 1



-Subparagraph (SX 210.7-03.16)



-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910



Reference 4: http://www.xbrl.org/2003/role/presentationRef



-Publisher SEC



-Name Regulation S-X (SX)



-Number 210



-Section 02



-Paragraph 20, 22



-Article 5

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=glt_VariableRateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=glt_FixedRateBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=glt_TwoPointFourZeroPercentTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=glt_TwoPointZeroFivePercentTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: