v3.26.1
Borrowings and Debentures - Long-term Borrowings (Detail) - KRW (₩)
₩ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of detailed information about borrowings [line items]    
Long-term borrowings ₩ 503,125 ₩ 515,600
Less: current portions (203,125) (312,475)
Long-term borrowings, excluding current installments 300,000 203,125
Gross amount [member]    
Disclosure of detailed information about borrowings [line items]    
Long-term borrowings ₩ 503,125 515,625
Gross amount [member] | Korea Development Bank Long-term borrowings with 1.87 Due Feb. 10, 2026 [member]    
Disclosure of detailed information about borrowings [line items]    
Annual interest rate (%) [1] 1.87%  
Maturity [1] Feb. 10, 2026  
Long-term borrowings [1] ₩ 3,125 15,625
Gross amount [member] | Mizuho Bank, Ltd. Long-term borrowings With 1.35 Due May. 20, 2024 [member]    
Disclosure of detailed information about borrowings [line items]    
Annual interest rate (%) 2.75%  
Maturity Sep. 22, 2027  
Long-term borrowings ₩ 200,000 0
Gross amount [member] | DBS Bank Ltd. Long-term borrowings With 2.63 Due Mar. 10, 2025 [member]    
Disclosure of detailed information about borrowings [line items]    
Annual interest rate (%) 2.63%  
Maturity Mar. 10, 2025  
Long-term borrowings ₩ 0 200,000
Gross amount [member] | Credit Agricole CIB Long-term borrowings With 4.89 Due Nov. 28, 2025 [member]    
Disclosure of detailed information about borrowings [line items]    
Annual interest rate (%) 4.89%  
Maturity Nov. 28, 2025  
Long-term borrowings ₩ 0 50,000
Gross amount [member] | Mizuho Bank, Ltd. Long-term borrowings With 3M CD + 1.05 Due Jul. 25, 2025 [member]    
Disclosure of detailed information about borrowings [line items]    
Annual interest rate description [2] 3M CD + 1.05  
Maturity [2] Jul. 25, 2025  
Long-term borrowings [2] ₩ 0 50,000
Gross amount [member] | Industrial and Commercial Bank of China Ltd. with Long term Borrowings 2.70 Due Sep.13,2027 [Member]    
Disclosure of detailed information about borrowings [line items]    
Annual interest rate (%) 2.70%  
Maturity Sep. 13, 2027  
Long-term borrowings, excluding current installments ₩ 100,000 0
Gross amount [member] | DBS Bank Ltd. Long-term Borrowings with 3M CD + 0.075 Due Oct. 8,2026 [member]    
Disclosure of detailed information about borrowings [line items]    
Annual interest rate description [2] 3M CD + 0.075  
Maturity [2] Oct. 8, 2026  
Long-term borrowings [2] ₩ 200,000 200,000
Present value discount [member]    
Disclosure of detailed information about borrowings [line items]    
Long-term borrowings ₩ 0 ₩ 25
[1] The long-term borrowings are to be repaid by installments on an annual basis from 2022 to 2026.
[2] Applied interest rate is the 3M CD rate of 2.85% and 3.41% as of December 31, 2025 and 2024, respectively.