Restricted Cash and Short-term Investments - Other-than-temporary Impairment (Details) $ in Thousands	6 Months Ended
Jun. 30, 2018 USD ($)
Short-term investments
Other-then-temporary impairment	$ 0

Amount of other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings and other comprehensive loss (OCI).

No definition available.

Name:	bgne_OtherThanTemporaryImpairmentLossDebtSecuritiesAvailableForSale
Namespace Prefix:	bgne_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration