XML 42 R58.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Leases - Summary of Minimum Lease Payments for Operating Lease Liabilities (Parenthetical) (Detail) $ in Millions | Dec. 31, 2019 USD ($)
--- | ---
Leases [Abstract] |
Non-cancelable future minimum lease payments for operating leases that have not yet commenced | $ 28.3

X
- Definition Non cancelable future minimum lease payments for operating leases not yet commenced. + References No definition available. + Details
Name: | nbix_NonCancelableFutureMinimumLeasePaymentsForOperatingLeasesNotYetCommenced
Namespace Prefix: | nbix_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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