v3.25.1
Cover - shares
 3 Months Ended
Mar. 31, 2025
May 01, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2025  
Document Transition Report false  
Entity File Number 001-38210  
Entity Registrant Name Krystal Biotech, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 82-1080209  
Entity Address, Address Line One 2100 Wharton Street  
Entity Address, Address Line Two Suite 701  
Entity Address, City or Town Pittsburgh  
Entity Address, State or Province PA  
Entity Address, Postal Zip Code 15203  
City Area Code 412  
Local Phone Number 586-5830  
Title of 12(b) Security Common Stock  
Trading Symbol KRYS  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   28,898,680
Entity Central Index Key 0001711279  
Amendment Flag false  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q1  
Current Fiscal Year End Date --12-31