v3.26.3
Cover
Oct. 25, 2026
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Oct. 25, 2026
Entity File Number 001-36182
Entity Registrant Name XENCOR, INC.
Entity Central Index Key 0001326732
Entity Tax Identification Number 20-1622502
Entity Incorporation, State or Country Code DE
Entity Address, Address Line One 465 North Halstead Street, Suite 200
Entity Address, City or Town Pasadena
Entity Address, State or Province CA
Entity Address, Postal Zip Code 91107
City Area Code 626
Local Phone Number 305-5900
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common Stock, par value $0.01 per share
Trading Symbol XNCR
Security Exchange Name NASDAQ
Entity Emerging Growth Company false