Quarterly report [Sections 13 or 15(d)]

Investments - Schedule of Fair Value Based upon Assumptions (Details)

v3.26.1
Investments - Schedule of Fair Value Based upon Assumptions (Details) - Valuation Technique Binomial Monte-Carlo Cliquet Option Pricing Model [Member]
₩ / shares in Units, ₩ in Billions
3 Months Ended 12 Months Ended
Mar. 31, 2026
KRW (₩)
₩ / shares
Dec. 31, 2025
KRW (₩)
₩ / shares
Mar. 31, 2026
$ / shares
Dec. 31, 2025
$ / shares
Schedule Of Investments [Line Items]        
Principal outstanding (South Korean won) | ₩ ₩ 17.0 ₩ 17.0    
Stock price | ₩ / shares ₩ 825 ₩ 917    
Expected Life (in years) [Member]        
Schedule Of Investments [Line Items]        
Expected life (in years) 4 years 6 months 18 days 4 years 9 months 14 days    
Selected Yield [Member]        
Schedule Of Investments [Line Items]        
Investment in convertible bonds, measurement input 15.00 13.50    
Expected Volatility (Telcon common stock) [Member]        
Schedule Of Investments [Line Items]        
Investment in convertible bonds, measurement input 69.25 67.04    
Risk-free Interest Rate (South Korea government bond) [Member]        
Schedule Of Investments [Line Items]        
Investment in convertible bonds, measurement input 3.76 3.21    
Expected Dividend Yield [Member]        
Schedule Of Investments [Line Items]        
Investment in convertible bonds, measurement input 0 0    
Conversion Price [Member]        
Schedule Of Investments [Line Items]        
Conversion price | (per share) ₩ 1,000 ₩ 1,000 $ 0.66 $ 0.69