Investment properties - Rental fee earned and operating expenses directly related to the investment properties (Details) - KRW (₩) ₩ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Rental income from investment property, net of direct operating expense [abstract] | ||
| Rental fee earned from investment properties | ₩ 34,888 | ₩ 23,307 |
| Direct operating expense from investment property generating rental income | ₩ 8,719 | ₩ 8,414 |