XML 22 R55.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Stock-Based Compensation - Schedule of Information Related to Outstanding SOSARS (Detail) (Stock Only Stock Appreciation Rights (SOSARs) [Member], USD $) In Thousands, except Share data, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2014 | Mar. 31, 2013
Stock Only Stock Appreciation Rights (SOSARs) [Member] |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Beginning Balance, Outstanding | 1,977,133 | 2,121,454
Granted | 275,529 | 361,923
Exercised | (15,974) | (40,986)
Canceled / forfeited |  | (23,920)
Ending Balance, Outstanding | 2,236,688 | 2,418,471
Beginning Balance, Weighted Average Exercise Price, Outstanding | $ 13.91 | $ 12.93
Weighted Average Exercise Price, Granted | $ 29.89 | $ 18.36
Weighted Average Exercise Price, Exercised | $ 15.48 | $ 13.90
Weighted Average Exercise Price, Canceled / forfeited |  | $ 15.61
Ending Balance, Weighted Average Exercise Price, Outstanding | $ 15.86 | $ 13.70
Weighted average grant date fair value per share | $ 9.85 | $ 5.64
Aggregate grant date fair value | $ 2,713 | $ 2,042
Black-Scholes assumptions |  |
Dividend yield | 1.47% | 2.18%
Risk free rate of return | 1.73% | 0.99%
Volatility | 37.59% | 39.62%
Expected life | 6 years | 6 years

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

X
- Definition Share based compensation arrangement by share based payment award options grant date fair value. + References No definition available. + Details
Name: | glt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDateFairValue
Namespace Prefix: | glt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Share based compensation arrangement by share Based payment award options grant date fair value per share. + References No definition available. + Details
Name: | glt_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDateFairValuePerShare
Namespace Prefix: | glt_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.D.2) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section D -Subsection 2 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iv) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average expected volatility rate of share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3)-(4) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average price of options that were either forfeited or expired. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3)-(4) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Gross number of share options (or share units) granted during the period. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of options outstanding, including both vested and non-vested options. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average price at which option holders acquired shares when converting their stock options into shares. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of share options (or share units) exercised during the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28,29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration