XML 67 R54.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Rationalizations Rationalization Text (Details) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 5 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jun. 30, 2016 | Sep. 30, 2014 | Dec. 31, 2015 | Dec. 31, 2016
South African Facility |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Impairment of Long-Lived Assets Held-for-use | $ 600 |  |  |
2014 Corporate and Research & Development Rationalization [Member] |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Percent of positions eliminated |  | 25.00% |  |
Successor [Member] |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Rationalizations |  |  | $ 1,195 | $ 75
Impairment of Long-Lived Assets Held-for-use |  |  | 0 | 2,843
Restructuring costs |  |  | $ 389 | $ 2,365

X
- Definition Current liability established for restructuring and related charges. + References No definition available. + Details
Name: | gti_RestructuringandRelatedLiability
Namespace Prefix: | gti_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 958 -SubTopic 225 -Section 45 -Paragraph 11 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51659069&loc=d3e92212-112881 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Impairment -URI http://asc.fasb.org/extlink&oid=6515133 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51719941&loc=d3e2921-110230 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2420-110228 + Details
Name: | us-gaap_ImpairmentOfLongLivedAssetsHeldForUse
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of positions eliminated during the period as a percentage of total positions eliminated during the period in connection with the restructuring plan(s). + References No definition available. + Details
Name: | us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent
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_RestructuringCostAndReserveLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after cash payment, of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 + Details
Name: | us-gaap_RestructuringCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=gti_SouthAfricanFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringPlanAxis=gti_A2014CorporateandResearchDevelopmentRationalizationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_SuccessorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |