XML 43 R32.htm IDEA: XBRL DOCUMENT
v3.19.2

Stock Options - Additional Information (Details) - USD ($) $ in Millions |  | 6 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Mar. 12, 2019 | Jun. 30, 2019 | Dec. 31, 2018 | Jun. 30, 2018 | May 31, 2018 | Dec. 31, 2016 | Apr. 30, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |
Options outstanding |  | 8,105,482 | 7,763,464 |  |  |  |
Stock options outstanding |  | 998,177 |  |  |  |  |
Unrecognized compensation cost |  | $ 25.0 |  |  |  |  |
Weighted-average period for recognition of compensation cost |  | 3 years 2 months 8 days |  |  |  |  |
Intrinsic value of options exercised |  | $ 4.6 |  | $ 0.6 |  |  |
2006 Plan |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |
Remaining shares available to be granted |  |  |  |  |  | 0 |
Options outstanding |  | 1,397,203 |  |  |  |  |
2015 Plan |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |
Options outstanding |  | 6,260,520 |  |  |  |  |
Common stock reserved for issuance |  |  |  |  | 8,211,980 |  | 5,270,095
2019 Plan |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |
Common stock reserved for issuance | 4,750,000 |  |  |  |  |  |
Allowed annual percentage increase in shares authorized as percentage of outstanding shares of common stock | 4.00% |  |  |  |  |  |
Maximum shares of common stock may be issued | 5,000,000 |  |  |  |  |  |
Stock options outstanding |  | 447,759 |  |  |  |  |
2019 ESPP |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |
Common stock reserved for issuance | 525,000 |  |  |  |  |  |
Allowed annual percentage increase in shares authorized as percentage of outstanding shares of common stock | 1.00% |  |  |  |  |  |
Maximum shares allowed to be issued under ESPP | 5,250,000 |  |  |  |  |  |
Purchase of common stock through payroll deductions expressed in percentage of fair market value | 85.00% |  |  |  |  |  |
Purchase rights outstanding under the ESPP |  | 0 |  |  |  |  |

X
- Definition Allowed annual percentage increase in shares authorized as percentage of outstanding shares of common stock. + References No definition available. + Details
Name: | dtil_AllowedAnnualPercentageIncreaseInSharesAuthorizedAsPercentageOfOutstandingSharesOfCommonStock
Namespace Prefix: | dtil_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum shares allowed to be issued. + References No definition available. + Details
Name: | dtil_MaximumSharesAllowedToBeIssued
Namespace Prefix: | dtil_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Maximum shares allowed to be issued under ESPP. + References No definition available. + Details
Name: | dtil_MaximumSharesAllowedToBeIssuedUnderESPP
Namespace Prefix: | dtil_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Purchase rights outstanding under the Employee Stock Purchase Plan. + References No definition available. + Details
Name: | dtil_PurchaseRightsOutstandingUnderESPP
Namespace Prefix: | dtil_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Share based compensation arrangement by share based payment award purchase price of common stock through payroll deductions percentage. + References No definition available. + Details
Name: | dtil_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePriceOfCommonStockThroughPayrollDeductionsPercentage
Namespace Prefix: | dtil_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + 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 (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unrecognized cost of unvested options awarded to employees as compensation. + 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 (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + 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 (a)(3) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + 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 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Gross number of share options (or share units) granted during the period. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of options outstanding, including both vested and non-vested options. + 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 -URI http://asc.fasb.org/extlink&oid=109197908&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 (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable. + 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 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_PlanNameAxis=dtil_TwoThousandSixStockIncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=dtil_TwoThousandFifteenStockIncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=dtil_TwoThousandNineteenIncentiveAwardPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=dtil_TwoThousandNineteenEmployeeStockPurchasePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |