XML 50 R36.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Organization And Summary Of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Debt Instrument [Line Items] |  |
Number of major product categories | 7 gti_NumberofMajorProductCategories |
Other Assets [Member] |  |
Debt Instrument [Line Items] |  |
Capitalized bank fees | $ 11.9 us-gaap_UnamortizedDebtIssuanceExpense / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherAssetsMember | $ 9.7 us-gaap_UnamortizedDebtIssuanceExpense / us-gaap_BalanceSheetLocationAxis = us-gaap_OtherAssetsMember

X
- Definition Number of Major Product Categories + References No definition available. + Details
Name: | gti_NumberofMajorProductCategories
Namespace Prefix: | gti_
Data Type: | xbrli:integerItemType
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 The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset. + 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 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_UnamortizedDebtIssuanceExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |