v3.26.1
Finance Income and Costs - Finance Income and Costs by Category of Financial Instruments (Detail) - KRW (₩)
₩ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about financial instruments [Line items]      
Finance income ₩ 219,358 ₩ 355,035 ₩ 248,376
Finance costs 481,996 605,919 527,401
Derivatives designated as hedging instrument 22,623 (6,573) (17,460)
Other comprehensive income (loss) for the year, net of taxes 1,529,834 160,776 (23,967)
Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income 219,358 355,035 248,376
Finance costs 481,996 605,919 527,401
Financial assets, class [member]      
Disclosure of detailed information about financial instruments [Line items]      
Other comprehensive income (loss) for the year, net of taxes 1,477,958 (1,145) (30,362)
Financial assets, class [member] | Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income 213,675 233,215 238,535
Finance costs 95,413 66,012 137,463
Financial liabilities, class [member]      
Disclosure of detailed information about financial instruments [Line items]      
Other comprehensive income (loss) for the year, net of taxes 1,488,136 4,680 (36,302)
Financial liabilities, class [member] | Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income 5,683 121,820 9,841
Finance costs 386,583 539,907 389,938
Financial assets at fair value through profit or loss [member] | Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income 84,582 95,708 127,001
Finance costs 38,798 52,731 114,668
Financial liabilities at fair value through profit or loss [member] | Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income 2,153 121,061 6,717
Finance costs 2,364 115,592 0
Financial liabilities measured at amortised cost [Member] | Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income 3,530 759 3,124
Finance costs 384,219 424,315 389,938
Financial assets at FVOCI [member]      
Disclosure of detailed information about financial instruments [Line items]      
Financial assets at FVOCI 1,465,513 11,253 (18,842)
Financial assets at FVOCI [member] | Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income 56,199 30,993 39,681
Finance costs 23,356 0 0
Financial assets at amortised cost, class [member] | Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income 72,894 106,514 69,373
Finance costs 33,259 13,281 22,795
Derivatives designated as hedging instrument [member]      
Disclosure of detailed information about financial instruments [Line items]      
Derivatives designated as hedging instrument 12,445 (12,398) (11,520)
Derivatives designated as hedging instrument [member] | Parent Company [Member]      
Disclosure of detailed information about financial instruments [Line items]      
Finance income     2,480
Finance costs     0
Derivatives designated as hedging instrument [member]      
Disclosure of detailed information about financial instruments [Line items]      
Derivatives designated as hedging instrument ₩ 10,178 ₩ 5,825 ₩ (5,940)