v3.26.1
Goodwill - Summary of Goodwill (Detail) - KRW (₩)
₩ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill ₩ 2,072,493 ₩ 2,072,493 ₩ 2,075,009
Shinsegi Telecom, Inc. [member]      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill 1,306,236 1,306,236  
SK Broadband Co., Ltd. [member]      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill 764,082 764,082  
Other goodwill [member]      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill ₩ 2,175 ₩ 2,175