Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Revenues	$ 874,837	$ 450,712	$ 331,412
Less:
Cost of product sales	19,075	12,269	4,481
Research and development (excluding stock-based compensation)	166,126	174,638	216,566
Stock-based compensation	85,066	65,413	55,615
Interest expense	78,872	98,516	108,239
Loss on extinguishment of debt	17,332	0	29,019
Other income	(12,090)	0	0
Income tax expense	3,530	1,927	310
Net income (loss)	263,861	(88,881)	(226,539)
Consolidated net income (loss)	263,861	(88,881)	(226,539)
Reportable Segment
Segment Reporting Information [Line Items]
Revenues	874,837	450,712	331,412
Less:
Cost of product sales	19,075	12,269	4,481
Sales and marketing (excluding stock-based compensation)	177,085	152,166	134,262
General and administrative (excluding stock-based compensation)	116,006	80,054	53,574
Stock-based compensation	85,066	65,413	55,615
Interest income	(10,668)	(14,746)	(15,777)
Interest expense	78,872	98,516	108,239
Foreign currency losses, net	152	641	1,039
Loss on extinguishment of debt	17,332	0	29,019
Other income	(12,090)	0	0
Income tax expense	3,530	1,927	310
Net income (loss)	263,861	(88,881)	(226,539)
Adjustments and reconciling items	0	0	0
Consolidated net income (loss)	263,861	(88,881)	(226,539)
Reportable Segment | Berotralstat
Less:
Research and development (excluding stock-based compensation)	12,148	10,950	13,780
Reportable Segment | BCX17725
Less:
Research and development (excluding stock-based compensation)	17,304	12,389	10,218
Reportable Segment | Avoralstat
Less:
Research and development (excluding stock-based compensation)	9,497	7,547	6,314
Reportable Segment | Factor D Program
Less:
Research and development (excluding stock-based compensation)	456	8,534	40,111
Reportable Segment | Research, discovery and preclinical programs
Less:
Research and development (excluding stock-based compensation)	17,677	12,733	12,286
Reportable Segment | Compensation and related personnel costs
Less:
Research and development (excluding stock-based compensation)	51,576	59,010	64,377
Reportable Segment | Other non-program specific and indirect costs
Less:
Research and development (excluding stock-based compensation)	$ 27,958	$ 32,190	$ 40,103