v3.26.1
Cover Page - shares
3 Months Ended
Mar. 31, 2026
May 05, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Current Fiscal Year End Date --12-31  
Document Transition Report false  
Entity File Number 001-37388  
Entity Registrant Name Talen Energy Corporation  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 47-1197305  
Entity Address, Address Line One 2929 Allen Pkwy, Suite 2200  
Entity Address, City or Town Houston  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 77019  
City Area Code 888  
Local Phone Number 211-6011  
Title of 12(b) Security Common stock, par value $0.001 per share  
Trading Symbol TLN  
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   45,395,007
Entity Central Key Index 0001622536  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Amendment Flag false