XML 75 R57.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Employee Benefit Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands |  | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
May 20, 2020 | Mar. 31, 2021 | Oct. 01, 2021 | Dec. 31, 2021 | Jan. 01, 2021 | Jan. 03, 2020 | Dec. 28, 2018
ESPP |  |  |  |  |  |  |
Number of shares available for grant |  |  |  | 11,004,584 |  |  |
Reduction in share reserve after stock option or stock appreciation award (in shares) |  |  |  | 1 |  |  |
Reduction in share reserve after all other awards (in shares) |  |  |  | 1.5 |  |  |
Increase in share reserve under 2017 plan (in shares) | 21,000,000 |  |  |  |  |  |
Stock options granted (in shares) |  |  |  | 2,573,000 |  |  |
Maximum potential to vest |  |  | 25.00% |  |  |  |
Stock-based compensation expense |  |  |  | $ 119,820 | $ 105,070 | $ 56,602 |
Expenses relating to stock match |  |  |  | $ 9,500 | 6,700 | 4,600 |
Minimum |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Number of months following change in control in which an employee was terminated |  |  |  | 1 month |  |  |
Maximum |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Number of months following change in control in which an employee was terminated |  |  |  | 13 months |  |  |
Stock options |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Expiration period |  |  |  | 7 years |  |  |
Total unrecognized compensation expense |  |  |  | $ 27,800 |  |  |
Unrecognized compensation expense weighted-average period for recognition |  |  |  | 2 years 8 months 12 days |  |  |
Intrinsic value of options exercised |  |  |  | $ 76,000 | 106,500 | 54,100 |
Cash received from option exercises and purchases under the ESPP |  |  |  | 14,800 | 26,900 | 16,400 |
Stock-based compensation expense |  |  |  | $ 19,048 | $ 19,863 | 23,422 |
Stock options | Share-based Payment Arrangement, Employee |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Award vesting period |  |  |  | 4 years |  |  |
Stock options | Share-based Payment Arrangement, Nonemployee |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Award vesting period |  |  |  | 1 year |  |  |
Restricted stock units |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Total unrecognized compensation expense |  |  |  | $ 123,600 |  |  |
Unrecognized compensation expense weighted-average period for recognition |  |  |  | 2 years 10 months 24 days |  |  |
Number of awards granted (in shares) |  |  |  | 4,220,000 |  |  |
Number of awards (in shares) |  |  |  | 6,828,000 | 5,378,000 |  |
Stock-based compensation expense |  |  |  | $ 53,629 | $ 35,675 | $ 26,056 |
Restricted stock units | Share-based Payment Arrangement, Employee |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Award vesting period |  |  |  | 4 years |  |  |
Restricted stock units | Share-based Payment Arrangement, Nonemployee |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Award vesting period |  |  |  | 1 year |  |  |
ESPP |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Number of shares available for grant |  |  |  | 3,168,354 |  |  |
Discount rate from market value on purchase date (as a percent) |  |  |  | 85.00% |  |  |
Discount rate from market value on offering date (as a percent) |  |  |  | 85.00% |  |  |
Common stock issued (in shares) |  |  |  | 536,226 | 534,419 | 483,009 |
Average price per share (in dollars per share) |  |  |  | $ 17.76 | $ 14.55 | $ 12.60 |
Proceeds from employee stock purchase plan |  |  |  | $ 9,500 | $ 7,800 | $ 6,100 |
Purchase period |  |  |  | 6 months |  |  |
Stock-based compensation expense |  |  |  | $ 3,715 | $ 2,426 | $ 2,246 |
Performance stock units |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Unrecognized compensation expense weighted-average period for recognition |  |  |  | 3 years |  |  |
Number of awards granted (in shares) |  | 1,027,650 |  | 2,056,000 |  | 3,853,210 | 693,131
Maximum potential to vest |  | 200.00% |  |  | 200.00% | 200.00% |
Additional shares to be earned (in shares) |  | 2,055,300 |  |  | 4,655,680 |  |
Number of awards (in shares) |  |  |  | 6,310,000 | 7,378,000 |  |
Stock-based compensation expense |  |  |  | $ 43,428 | $ 47,106 | $ 4,878 |
Performance stock units | Share-based Payment Arrangement, Tranche One |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Vesting award percentage |  | 50.00% |  |  |  |  |
Performance stock units | Share-based Payment Arrangement, Tranche Two |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Award vesting period |  | 1 year |  |  |  |  |
Performance stock units | Achieved |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Number of awards (in shares) |  |  |  | 4,853,112 |  |  |
Performance stock units | Probable |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Total unrecognized compensation expense |  |  |  | $ 12,100 |  |  |
Performance stock units | Not Probable |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Total unrecognized compensation expense |  |  |  | $ 121,600 |  |  |
Performance Shares, Clinical Trial Results |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Number of awards granted (in shares) |  |  |  |  | 2,327,840 | 1,926,605 |
Performance Shares, Achieved Before December 31, 2020 |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Maximum potential to vest |  |  |  |  | 150.00% |  |
Performance Shares, Achieved Before December 31, 2021 |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Maximum potential to vest |  |  |  | 50.00% |  |  |
2018 Performance Stock Units |  |  |  |  |  |  |
ESPP |  |  |  |  |  |  |
Number of awards vested in period (in shares) |  |  |  |  | 167,726 |  |

X
- Definition Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other than Options, Maximum Number Of Shares To Vest + References No definition available. + Details
Name: | exel_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherthanOptionsMaximumNumberOfSharesToVest
Namespace Prefix: | exel_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-Based Compensation Arrangement By Share-Based Payment Award, Reduction In Share Reserve Due To Other Awards + References No definition available. + Details
Name: | exel_ShareBasedCompensationArrangementByShareBasedPaymentAwardReductionInShareReserveDueToOtherAwards
Namespace Prefix: | exel_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-Based Compensation Arrangement By Share-Based Payment Award, Reduction In Share Reserve Due To Stock Option Or Stock Appreciation Award + References No definition available. + Details
Name: | exel_ShareBasedCompensationArrangementByShareBasedPaymentAwardReductionInShareReserveDueToStockOptionOrStockAppreciationAward
Namespace Prefix: | exel_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-Based Payment Arrangement By Share-Based Payment Award, Termination Of Employment Following Change In Control, Period + References No definition available. + Details
Name: | exel_ShareBasedPaymentArrangementByShareBasedPaymentAwardTerminationOfEmploymentFollowingChangeInControlPeriod
Namespace Prefix: | exel_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Maximum Potential To Vest + References No definition available. + Details
Name: | exel_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsMaximumPotentialToVest
Namespace Prefix: | exel_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date, Purchase Period + References No definition available. + Details
Name: | exel_SharebasedCompensationArrangementbySharebasedPaymentAwardDiscountfromMarketPriceOfferingDatePurchasePeriod
Namespace Prefix: | exel_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=122041274&loc=d3e301413-122809 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 (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cost not yet recognized for nonvested award under share-based payment arrangement. + 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=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents 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=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cash inflow from exercise of option under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120381028&loc=SL79508275-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow associated with the amount received from the stock plan during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromStockPlans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + 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)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount rate from fair value on offering date that participants pay for shares. + 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=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount rate from fair value on purchase date that participants pay for shares. + 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=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + 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 (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. + 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 (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. + 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 (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of additional shares authorized for issuance under share-based payment arrangement. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

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=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. + 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)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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 Per share weighted-average price paid for shares purchased on open market for issuance under share-based payment arrangement. + 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=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 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares issued under share-based payment arrangement. + 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=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of vesting of award under share-based payment arrangement. + 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)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period from grant date that an equity-based award expires, 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 (a)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GranteeStatusAxis=us-gaap_ShareBasedPaymentArrangementEmployeeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GranteeStatusAxis=us-gaap_ShareBasedPaymentArrangementNonemployeeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | exel_StatusAxis=exel_AchievedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | exel_StatusAxis=exel_ProbableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | exel_StatusAxis=exel_NotProbableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=exel_PerformanceSharesClinicalTrialResultsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=exel_PerformanceSharesAchievedBeforeDecember312020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=exel_PerformanceSharesAchievedBeforeDecember312021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=exel_A2018PerformanceStockUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |