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v3.26.1

General Information - Additional Information (Detail) ₩ in Millions | 12 Months Ended
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Dec. 31, 2025 KRW (₩) Entity | Dec. 31, 2024 KRW (₩) | Dec. 31, 2023 KRW (₩)
Disclosure of general information [Line Items] |  |  |
Number of associates and joint ventures | Entity | 115 |  |
Increase (decrease) in ownership interests in subsidiaries | ₩ 772,803 | ₩ 462,168 | ₩ 262,746
Dividends paid by subsidiaries | 946,248 | 1,403,415 | ₩ 441,113
POSCO INTERNATIONAL Corporation And Others [Member] |  |  |
Disclosure of general information [Line Items] |  |  |
Increase (decrease) in ownership interests in subsidiaries |  | ₩ 15,440 |
POSCO HY Clean Metal Co., Ltd. and others [Member] |  |  |
Disclosure of general information [Line Items] |  |  |
Increase (decrease) in ownership interests in subsidiaries | ₩ 35,662 |  |
Domestic [member] |  |  |
Disclosure of general information [Line Items] |  |  |
Number of subsidiaries | Entity | 64 |  |
Foreign [member] |  |  |
Disclosure of general information [Line Items] |  |  |
Number of subsidiaries | Entity | 134 |  |

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- Details
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