XML 97 R59.htm IDEA: XBRL DOCUMENT
v3.23.4

Net Loss Per Share Attributable to Common Stockholders - Schedule of Anti-dilutive Outstanding Shares or Equivalents (Details) - shares | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2022 | Dec. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |  |  |  |
Anti-dilutive outstanding shares or equivalents | 7,264,014 | 11,214,630 | 7,264,014 | 11,214,630 | 10,690,909,000 | 9,930,793,000
Options To Purchase Common Stock |  |  |  |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |  |  |  |
Anti-dilutive outstanding shares or equivalents | 6,380,515 | 7,849,590 | 6,380,515 | 7,849,590 | 7,755,303,000 | 5,056,743,000
Common Stock Subject To Vesting Or Repurchase |  |  |  |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |  |  |  |
Anti-dilutive outstanding shares or equivalents | 873,062 | 3,236,152 | 873,062 | 3,236,152 | 2,767,526,000 | 4,774,798,000
Employee Stock Purchase Plan shares |  |  |  |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |  |  |  |
Anti-dilutive outstanding shares or equivalents | 10,437 | 128,888 | 10,437 | 128,888 | 168,080,000 | 99,252,000

X
- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482662/260-10-50-1 + Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
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_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=grph_OptionsToPurchaseCommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=grph_CommonStockSubjectToVestingOrRepurchaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=grph_EmployeeStockPurchasePlanSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |