v3.26.1
Derivative Instruments - Details of Fair Values of the Above Derivatives Recorded in Assets or Liabilities (Detail) - KRW (₩)
₩ in Millions
Dec. 31, 2025
Dec. 31, 2024
Disclosure of detailed information about hedged items [line items]    
Short-term derivative financial assets ₩ 6,945 ₩ 119,500
Long-term derivative financial assets 303,201 221,608
Long-term derivative financial liabilities (621) ₩ (3,437)
Cash flow hedge [member]    
Disclosure of detailed information about hedged items [line items]    
Short-term derivative financial assets 201,262  
Long-term derivative financial liabilities (621)  
Fair value [member]    
Disclosure of detailed information about hedged items [line items]    
Short-term derivative financial assets 201,262  
Long-term derivative financial liabilities (621)  
Floating-to-fixed interest rate swap,Oct. 7,2024 [member] | Cash flow hedge [member]    
Disclosure of detailed information about hedged items [line items]    
Long-term derivative financial liabilities (621)  
Floating-to-fixed interest rate swap,Oct. 7,2024 [member] | Fair value [member]    
Disclosure of detailed information about hedged items [line items]    
Long-term derivative financial liabilities (621)  
Fixed-to-fixed cross currency swap, Jul. 20, 2007 [member] | Cash flow hedge [member]    
Disclosure of detailed information about hedged items [line items]    
Long-term derivative financial assets 137,222  
Fixed-to-fixed cross currency swap, Jul. 20, 2007 [member] | Fair value [member]    
Disclosure of detailed information about hedged items [line items]    
Long-term derivative financial assets 137,222  
Floating-to-fixed cross-currency interest rate swap, Mar. 4, 2020 [member] | Cash flow hedge [member]    
Disclosure of detailed information about hedged items [line items]    
Short-term derivative financial assets 19,034  
Floating-to-fixed cross-currency interest rate swap, Mar. 4, 2020 [member] | Fair value [member]    
Disclosure of detailed information about hedged items [line items]    
Short-term derivative financial assets 19,034  
Fixed-to-fixed cross currency swap, Jun. 28, 2023 [member] | Cash flow hedge [member]    
Disclosure of detailed information about hedged items [line items]    
Long-term derivative financial assets 45,006  
Fixed-to-fixed cross currency swap, Jun. 28, 2023 [member] | Fair value [member]    
Disclosure of detailed information about hedged items [line items]    
Long-term derivative financial assets ₩ 45,006