Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) segment	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Segment Information
Number of reportable segments | segment			2
Accumulated deficit	$ 933,375		$ 933,375		$ 902,861
Total revenue	1,777	$ 2,766	3,232	$ 5,163
Total research and development	11,449	8,759	23,033	18,604
General and administrative	5,386	4,752	11,525	11,596
Licensing	1,335	1,285	2,345	2,316
Revaluation of contingent consideration	1,500	200	1,800	3,000
Segment operating loss	(18,408)	(12,854)	(36,492)	(31,786)
Other income	2,979	1,868	5,978	3,859
Loss before income taxes	(15,429)	(10,986)	(30,514)	(27,927)
Operating Segments | Therapeutics Segment
Segment Information
Total revenue	1,335	2,141	2,345	3,882
Total research and development project expenses	7,108	5,144	14,376	9,842
Personnel	2,984	2,329	5,911	7,032
Other research and development expense	1,580	1,500	3,193	2,177
Total research and development	11,672	8,973	23,480	19,051
Licensing	1,335	1,285	2,345	2,316
Revaluation of contingent consideration	1,500	200	1,800	3,000
Segment operating loss	(13,172)	(8,317)	(25,280)	(20,485)
Operating Segments | Contract Research Segment
Segment Information
Total revenue	442	625	887	1,281
Cost of revenue	3,812	3,832	7,529	8,073
General and administrative	622	1,020	1,522	2,128
Segment operating loss	(472)	(805)	(1,209)	(1,833)
Operating Segments | Bosakitug | Therapeutics Segment
Segment Information
Total research and development project expenses	2,847		6,231
Operating Segments | ATI-2138 | Therapeutics Segment
Segment Information
Total research and development project expenses	1,118	753	2,926	815
Operating Segments | ATI-052 | Therapeutics Segment
Segment Information
Total research and development project expenses	1,418		2,037
Operating Segments | Lepzacitinib | Therapeutics Segment
Segment Information
Total research and development project expenses		296		1,368
Operating Segments | Zunsemetinib | Therapeutics Segment
Segment Information
Total research and development project expenses	105	2,490	216	4,514
Operating Segments | Discovery | Therapeutics Segment
Segment Information
Total research and development project expenses	1,620	1,605	2,966	3,145
Intersegment Eliminations
Segment Information
Total revenue	(3,520)	(3,422)	(6,955)	(7,087)
Cost of revenue	(3,297)	(3,208)	(6,508)	(6,640)
Total research and development	(223)	(214)	(447)	(447)
Intersegment Eliminations | Contract Research Segment
Segment Information
Total revenue	3,520	3,422	6,955	7,087
Total
Segment Information
Total revenue	1,777	2,766	3,232	5,163
Cost of revenue	515	624	1,021	1,433
Total research and development project expenses	7,108	5,144	14,376	9,842
Personnel	2,984	2,329	5,911	7,032
Other research and development expense	1,580	1,500	3,193	2,177
Total research and development	11,449	8,759	23,033	18,604
General and administrative	622	1,020	1,522	2,128
Licensing	1,335	1,285	2,345	2,316
Revaluation of contingent consideration	1,500	200	1,800	3,000
Segment operating loss	(13,644)	(9,122)	(26,489)	(22,318)
Total | Bosakitug
Segment Information
Total research and development project expenses	2,847		6,231
Total | ATI-2138
Segment Information
Total research and development project expenses	1,118	753	2,926	815
Total | ATI-052
Segment Information
Total research and development project expenses	1,418		2,037
Total | Lepzacitinib
Segment Information
Total research and development project expenses		296		1,368
Total | Zunsemetinib
Segment Information
Total research and development project expenses	105	2,490	216	4,514
Total | Discovery
Segment Information
Total research and development project expenses	1,620	1,605	2,966	3,145
Reconciliation of segment
Segment Information
General and administrative	4,764	3,732	10,003	9,468
Other income	$ 2,979	$ 1,868	$ 5,978	$ 3,859