XML 76 R63.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Debt And Liquidity (Revolving Faciltity) (Details) - USD ($) | Feb. 27, 2015 | Dec. 31, 2016 | Apr. 27, 2016 | Aug. 11, 2015 | Jul. 28, 2015 | Apr. 23, 2014
--- | --- | --- | --- | --- | --- | ---
Debt Instrument [Line Items] |  |  |  |  |  |
Minimum Liquidity |  |  | $ 25,000,000 |  |  |
12 Month Trailing EBITDA |  | $ 75,000,000 |  |  |  |
12 Month Trailing EBITDA Minimum (Low End) |  |  | 40,000,000 |  |  |
12 Month Trailing EBITDA Minimum (High End) |  |  | 35,000,000 |  |  |
Revolving Credit Facility Balance |  | 61,200,000 |  |  |  |
Letters of Credit Outstanding, Amount |  | 12,300,000 |  |  |  |
Term Loan Balance |  | $ 29,500,000 |  | $ 40,000,000 |  |
Revolving Credit Facility [Member] | Amended and Restated Credit Agreement February 2015 [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  |  |  |  | $ 400,000,000
Revolving Credit Facility [Member] | Amended and Restated Credit Agreement July 2015 [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  | $ 225,000,000 |  | $ 375,000,000 |
Term Loan Facility [Member] | Amended and Restated Credit Agreement February 2015 [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | $ 40,000,000 |  |  |  |  |
Term Loan Facility [Member] | Amended and Restated Credit Agreement July 2015 [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  |  |  | $ 40,000,000 |
Minimum [Member] | Amended and Restated Credit Agreement February 2015 [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.35% |  |  |  |  |
Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member] | Amended and Restated Credit Agreement February 2015 [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 2.25% |  |  |  |  |
Maximum [Member] | Amended and Restated Credit Agreement February 2015 [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 0.70% |  |  |  |  |
Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member] | Amended and Restated Credit Agreement February 2015 [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 4.75% |  |  |  |  |

X
- Definition 12 Month Trailing EBITDA + References No definition available. + Details
Name: | gti_A12MonthTrailingEBITDA
Namespace Prefix: | gti_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 12 Month Trailing EBITDA Minimum (High End) + References No definition available. + Details
Name: | gti_A12MonthTrailingEBITDAMinimumHighEnd
Namespace Prefix: | gti_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 12 Month Trailing EBITDA Minimum (Low End) + References No definition available. + Details
Name: | gti_A12MonthTrailingEBITDAMinimumLowEnd
Namespace Prefix: | gti_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Minimum liquidity required by credit facility + References No definition available. + Details
Name: | gti_MinimumLiquidity
Namespace Prefix: | gti_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Revolving credit facility portion of total credit facility outstanding + References No definition available. + Details
Name: | gti_RevolvingCreditFacilityBalance
Namespace Prefix: | gti_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Term loan portion of revolving credit facility balance + References No definition available. + Details
Name: | gti_TermLoanBalance
Namespace Prefix: | gti_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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 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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
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 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility. + References No definition available. + Details
Name: | us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gti_AmendedandRestatedCreditAgreementFebruary2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gti_AmendedandRestatedCreditAgreementJuly2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=gti_TermLoanFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |