Lease Obligations - Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
2025 (remaining)	$ 1,509
2026	1,790
2027	1,705
2028	1,401
2029	996
Thereafter	6,922
Total lease payments	14,323
Less imputed interest	(5,473)
Total	8,850	$ 8,861
Finance Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
2025 (remaining)	1,692
2026	1,487
2027	1,017
2028	451
2029	6
Thereafter	0
Total lease payments	4,653
Less imputed interest	(544)
Total	$ 4,109	$ 3,959

Finance Lease, Liability, to be Paid, After Year Four

No definition available.

Name:	bcrx_FinanceLeaseLiabilityToBePaidAfterYearFour
Namespace Prefix:	bcrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease due after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.