XML 80 R60.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Long-Term Debt - Additional Information (Detail) | 3 Months Ended |  | 3 Months Ended |  | 3 Months Ended |  | 3 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 31, 2014 USD ($) | Mar. 31, 2014 IKB Loan [Member] Installment | Apr. 11, 2013 IKB Loan [Member] USD ($) | Apr. 11, 2013 IKB Loan [Member] EUR (€) | Mar. 31, 2014 Maximum [Member] | Mar. 31, 2014 Federal Funds Rate [Member] | Mar. 31, 2014 5.375% Notes [Member] | Oct. 03, 2012 5.375% Notes [Member] USD ($) | Mar. 31, 2014 Revolving Credit Facility [Member] | Nov. 21, 2011 Revolving Credit Facility [Member] USD ($) | Mar. 31, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] | Mar. 31, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] Minimum [Member] | Mar. 31, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] Maximum [Member] | Mar. 31, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] Daily Euro Rate [Member] Minimum [Member] | Mar. 31, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] Daily Euro Rate [Member] Maximum [Member] | Mar. 31, 2014 Letters of Credit [Member] USD ($) | Dec. 31, 2013 Letters of Credit [Member] USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  |  | $ 350,000,000 |  |  |  |  |  |  |
Debt instrument maturity date |  |  |  |  |  |  | Oct. 15, 2020 |  | Nov. 21, 2016 |  | Nov. 30, 2016 |  |  |  |  |  |
Federal fund rate spread |  |  |  |  |  | 0.50% |  |  |  |  |  | 0.25% | 1.25% | 1.25% | 2.25% |  |
Margin over Euro-rate | 1.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Leverage ratio | 2.36 |  |  |  | 3.50 |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  | 57,600,000 | 42,700,000 |  |  |  | 250,000,000 |  |  |  |  |  |  |  |  |
Percentage of aggregate principal amount of outstanding |  | 2.05% |  |  |  |  | 5.375% | 5.375% |  |  |  |  |  |  |  |  |
Net proceeds used to refinance previous debt | 200,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Frequency of interest payable |  |  |  |  |  |  | Semiannually |  |  |  |  |  |  |  |  |  |
Number of installments |  | 32 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Installments beginning date |  | Jun. 30, 2015 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Installments ending date |  | Mar. 31, 2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Letters of credit issued |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,200,000 | 5,200,000
Letters of credit outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 |

X
- Definition Amount of Letters of Credit Issued and Reducing Availability under Revolving Credit Facility + References No definition available. + Details
Name: | glt_AmountOfLettersOfCreditIssuedAndReducingAvailabilityUnderRevolvingCreditFacility
Namespace Prefix: | glt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt instrument number of installment payment. + References No definition available. + Details
Name: | glt_DebtInstrumentNumberOfInstallmentPayment
Namespace Prefix: | glt_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ratio of EBITDA over net debt. + References No definition available. + Details
Name: | glt_LeverageRatio
Namespace Prefix: | glt_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loan repayable installments end date. + References No definition available. + Details
Name: | glt_LoanRepayableInstallmentsEndDate
Namespace Prefix: | glt_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loan repayable installments start date. + References No definition available. + Details
Name: | glt_LoanRepayableInstallmentsStartDate
Namespace Prefix: | glt_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Margin over Euro-rate. + References No definition available. + Details
Name: | glt_MarginOverEuroRate
Namespace Prefix: | glt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Description of the frequency of periodic payments (monthly, quarterly, annual). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 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 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentFrequencyOfPeriodicPayment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 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(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 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(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash inflow from a borrowing with the highest claim on the assets of the entity in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle, if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration