Earnings per share - Summary Of Earnings Per Share (Details) ₩ / shares in Units, $ / shares in Units, $ in Thousands, ₩ in Millions	12 Months Ended
Dec. 31, 2025 KRW (₩) ₩ / shares shares	Dec. 31, 2025 USD ($) $ / shares shares	Dec. 31, 2024 KRW (₩) ₩ / shares shares	Dec. 31, 2023 KRW (₩) ₩ / shares shares
Basic earnings per share [abstract]
Net income attributable to common shareholders	₩ 3,124,346	$ 2,162,851	₩ 3,085,995	₩ 2,506,296
Dividends to hybrid securities	(150,059)		(158,682)	(131,148)
Net income attributable to common shareholders	₩ 2,974,287		₩ 2,927,313	₩ 2,375,148
Weighted average number of common shares outstanding \| shares	733,713,889	733,713,889	741,273,152	735,000,000
Basic EPS (Unit: Korean Won) \| (per share)	₩ 4,052	$ 2,805	₩ 3,950	₩ 3,230
Diluted EPS (Unit: Korean Won) \| (per share)	₩ 4,052	$ 2,805	₩ 3,950	₩ 3,230

The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator) divided by the weighted average number of ordinary shares outstanding during the period (the denominator).

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The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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The profit (loss) attributable to ordinary equity holders of the parent entity. [Refer: Profit (loss)]

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The profit (loss) from continuing and discontinued operations attributable to owners of the parent. [Refer: Profit (loss)]

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The profit (loss) used in calculating basic earnings (loss) per instrument attributable to equity instruments that participate in profit with ordinary shares according to a predetermined formula. [Refer: Profit (loss)]

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The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor.

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