XML 48 R65.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Subsequent Events (Details) (Subsequent Event, USD $) | 0 Months Ended |
--- | --- | ---
Apr. 29, 2015 | Apr. 29, 2015 series
Subsequent Event [Line Items] |  |
Share purchase price (usd per share) | $ 5.05 us-gaap_SaleOfStockPricePerShare | $ 5.05 us-gaap_SaleOfStockPricePerShare
Preferred Stock |  |
Subsequent Event [Line Items] |  |
Value of shares authorized for transaction | $ 150,000,000 gti_SaleofStockValueofSharesAuthorizedforTransaction / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember | $ 150,000,000 gti_SaleofStockValueofSharesAuthorizedforTransaction / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Preferred stock, dividend rate | 7.00%us-gaap_PreferredStockDividendRatePercentage / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |
Number of series stock will be issued in | 2 gti_SaleofStockNumberofSeriesStockIssued / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember | 2 gti_SaleofStockNumberofSeriesStockIssued / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Series one, maximum conversion percent of outstanding common stock | 19.90%gti_ConvertiblePreferredStockSeriesOneMaximumPercentofOutstandingCommonStock / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember | 19.90%gti_ConvertiblePreferredStockSeriesOneMaximumPercentofOutstandingCommonStock / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Conversion price (usd per share) | $ 5.00 gti_ConvertiblePreferredStockConversionPrice / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember | $ 5.00 gti_ConvertiblePreferredStockConversionPrice / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Series two, maximum conversion percent of outstanding common stock | 2.00%gti_ConvertiblePreferredStockSeriesTwoMaximumPercentofOutstandingCommonStock / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember | 2.00%gti_ConvertiblePreferredStockSeriesTwoMaximumPercentofOutstandingCommonStock / us-gaap_StatementEquityComponentsAxis = us-gaap_PreferredStockMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember

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- Definition Convertible Preferred Stock, Conversion Price + References No definition available. + Details
Name: | gti_ConvertiblePreferredStockConversionPrice
Namespace Prefix: | gti_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

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- Definition Convertible Preferred Stock, Series One, Maximum Percent of Outstanding Common Stock + References No definition available. + Details
Name: | gti_ConvertiblePreferredStockSeriesOneMaximumPercentofOutstandingCommonStock
Namespace Prefix: | gti_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Definition Convertible Preferred Stock, Series Two, Maximum Percent of Outstanding Common Stock + References No definition available. + Details
Name: | gti_ConvertiblePreferredStockSeriesTwoMaximumPercentofOutstandingCommonStock
Namespace Prefix: | gti_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Definition Sale of Stock, Number of Series Stock Issued + References No definition available. + Details
Name: | gti_SaleofStockNumberofSeriesStockIssued
Namespace Prefix: | gti_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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- Definition Sale of Stock, Value of Shares Authorized for Transaction + References No definition available. + Details
Name: | gti_SaleofStockValueofSharesAuthorizedforTransaction
Namespace Prefix: | gti_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition The percentage rate used to calculate dividend payments on preferred stock. + References No definition available. + Details
Name: | us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

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

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- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_PreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |