XML 52 R32.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Organization and Summary of Significant Accounting Policies - Additional Information (Detail) shares in Millions |  | 12 Months Ended
--- | --- | ---
May 02, 2017 USD ($) shares | Dec. 31, 2017 USD ($) Subsidiary Agreement shares | Dec. 31, 2016 USD ($) shares | Dec. 31, 2015 USD ($) shares
Organization And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Number of subsidiary wholly-owned by company | Subsidiary |  | 2 |  |
Investment income, net |  | $ 6,238,000 | $ 2,838,000 | $ 1,928,000
Convertible senior notes principal amount |  | $ 517,500,000 |  |
Number of collaboration agreements | Agreement |  | 2 |  |
2.25% Convertible Senior Notes due 2024 |  |  |  |
Organization And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Convertible senior notes |  | 7 years |  |
Fair value of convertible senior note as percentage of principal amount |  | 128.00% |  |
Common share equivalents excluded from computation of earnings per share | shares | 6.8 |  |  |
Convertible senior notes principal amount | $ 517,500,000 |  |  |
Restricted Stock Units and Employee Options |  |  |  |
Organization And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Common share equivalents excluded from computation of earnings per share | shares |  | 3.4 | 3.8 | 4.1
Stock Options |  |  |  |
Organization And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Common share equivalents excluded from computation of earnings per share | shares |  | 0.4 | 0.4 | 0.1
Ingrezza |  |  |  |
Organization And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Advertising costs |  | $ 10,100,000 |  |
Prepaid expenses, advertising costs |  | $ 0 |  |
Minimum |  |  |  |
Organization And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Average estimated useful life of equipment |  | 3 years |  |
Requisite service period of award |  | 3 years |  |
Maximum |  |  |  |
Organization And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Average estimated useful life of equipment |  | 7 years |  |
Requisite service period of award |  | 4 years |  |

X
- Definition Debt instrument fair value percentage of principal. + References No definition available. + Details
Name: | nbix_DebtInstrumentFairValuePercentageOfPrincipal
Namespace Prefix: | nbix_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of collaboration agreements. + References No definition available. + Details
Name: | nbix_NumberOfCollaborationAgreements
Namespace Prefix: | nbix_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Subsidiaries Held + References No definition available. + Details
Name: | nbix_NumberOfSubsidiariesHeld
Namespace Prefix: | nbix_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Organization And Summary Of Significant Accounting Policies [Line Items] + References No definition available. + Details
Name: | nbix_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems
Namespace Prefix: | nbix_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 720 -SubTopic 35 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848 + Details
Name: | us-gaap_AdvertisingExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.8) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.7(a),(b)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.9) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_InvestmentIncomeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of consideration paid in advance for advertising that provides economic benefits within a future period of one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 340 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=84159346&loc=d3e8275-108329 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 720 -SubTopic 35 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (g)(6) -URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 340 -SubTopic 10 -Section 05 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=68074540&loc=d3e5865-108316 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6787-107765 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 340 -SubTopic 10 -Section 05 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=68074540&loc=d3e5879-108316 + Details
Name: | us-gaap_PrepaidAdvertising
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=nbix_SeniorConvertibleNotesTwoPointTwoFivePercentDueInMayTwoThousandTwentyFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | us-gaap_ProductOrServiceAxis=nbix_IngrezzaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |