Revenue (Details) $ in Thousands, ¥ in Billions	3 Months Ended
	Mar. 31, 2025 USD ($)	Mar. 31, 2024	Mar. 31, 2025 JPY (¥)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue recognized	$ 17,389
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	us-gaap:LicenseMember	us-gaap:LicenseMember
Deferred revenue, non-current	$ 2,611
Collaborative Arrangement for Product ESK-001
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, Remaining Performance Obligation	24,100
Collaborative Arrangement for Product ESK-001 | Development services obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, Remaining Performance Obligation	20,800
Collaborative Arrangement for Product ESK-001 | Material right obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, Remaining Performance Obligation	3,300
Kaken Pharmaceutical Co., Ltd | Collaborative Arrangement for Product ESK-001
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Upfront, non-refundable payment	20,000
Global development cost reimbursement	20,000
Maximum achievement of regulatory milestones	36,000
Maximum achievement of commercial milestones | ¥			¥ 15.5
Amount allocated to license obligation	17,400
Amount allocated to Development Services Obligation	20,800
Amount allocated to Material Right Obligation	3,300
Kaken Pharmaceutical Co., Ltd | Collaborative Arrangement for Product ESK-001 | Global development cost reimbursement in the dermatology field through the end of 2026
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Global development cost reimbursement	20,000
Kaken Pharmaceutical Co., Ltd | Collaborative Arrangement for Product ESK-001 | Estimated global development cost reimbursement in the dermatology field after 2026
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Global development cost reimbursement	$ 1,500