XML 47 R35.htm IDEA: XBRL DOCUMENT
v3.20.2

Stock-Based Compensation (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2020
Share-based Payment Arrangement [Abstract] |
Shares Authorized For Distribution | Stock-based compensation awards granted by our Board of Directors for the three and nine months ended September 30, 2020 and 2019 were as follows:
| For the Three Months Ended September 30, |  | For the Nine Months Ended September 30, |  |
| 2020 |  | 2019 |  | 2020 |  | 2019 |  |  |  |
Award type: |  |  |  |  |  |  |  |  |  |  |
Stock options | 4,000 |  |  | — |  |  | 304,000 |  |  | 207,000 |  |  |  |  |
Deferred share units | 20,027 |  |  | 16,176 |  |  | 44,670 |  |  | 23,121 |  |  |  |  |
Restricted stock units | 16,729 |  |  | 1,551 |  |  | 328,720 |  |  | 235,170 |  |  |  |  |
Share-based Compensation, Stock Options, Activity | Stock Option, Deferred Share Unit and Restricted Stock Unit awards activity under the Omnibus Equity Incentive Plan for the nine months ended September 30, 2020 was as follows: Stock Options
| Number of Shares |  | Weighted- Average Exercise Price
Outstanding unvested as of December 31, 2019 | 931,658 |  |  | $ | 15.06 |
Granted | 304,000 |  |  | 8.99 |
Vested | (186,162) |  |  | 15.20 |
Forfeited | (143,960) |  |  | 14.82 |
Outstanding unvested as of September 30, 2020 | 905,536 |  |  | $ | 13.03 |
Share-based Compensation, Deferred Share Unit And Restricted Stock Unit, Activity |
| Number of Shares |  | Weighted- Average Grant Date Fair Value
Outstanding unvested as of December 31, 2019 | 282,716 |  |  | $ | 12.83 |
Granted | 373,390 |  |  | 8.77 |
Vested | (87,112) |  |  | 10.18 |
Forfeited | (45,760) |  |  | 12.24 |
Outstanding unvested as of September 30, 2020 | 523,234 |  |  | $ | 10.43 |

X
- Definition Share-based Compensation, Deferred Share Unit And Restricted Stock Unit, Activity [Table Text Block] + References No definition available. + Details
Name: | gti_SharebasedCompensationDeferredShareUnitAndRestrictedStockUnitActivityTableTextBlock
Namespace Prefix: | gti_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Shares Authorized For Distribution [Table Text Block] + References No definition available. + Details
Name: | gti_SharesAuthorizedForDistributionTableTextBlock
Namespace Prefix: | gti_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration