XML 129 R119.htm IDEA: XBRL DOCUMENT v3.26.1
Investments in Associates and Joint Ventures - Changes in Investments in Associates and Joint Ventures (Detail) - KRW (₩)
₩ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance ₩ 4,738,793 ₩ 5,020,264  
Acquisition 213,279 298,176  
Dividends (376,109) (511,189)  
Share of profits (losses) 349,910 (256,458) ₩ 269,678
Other increase (decrease) 54,280 188,000  
Book value, ending balance 4,980,153 4,738,793 5,020,264
Domestic [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 764,354 792,855  
Acquisition 43,106 38,217  
Dividends (8,238) (18,282)  
Share of profits (losses) (32,147) (22,382)  
Other increase (decrease) (1,144) (26,054)  
Book value, ending balance 765,931 764,354 792,855
Domestic [member] | Samcheok Blue Power Co.,Ltd. [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 392,269 323,521  
Acquisition 17,509 25,680  
Dividends (2,795) (10,993)  
Share of profits (losses) 7,595 54,140  
Other increase (decrease) 7,121 (79)  
Book value, ending balance 421,699 392,269 323,521
Domestic [member] | SNNC [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 38,046 100,692  
Dividends 0    
Share of profits (losses) (35,826) (61,898)  
Other increase (decrease) 144 (748)  
Book value, ending balance 2,364 38,046 100,692
Domestic [member] | Chun-cheon Energy Co., Ltd. [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 14,054 15,040  
Share of profits (losses) 2,016 1,807  
Other increase (decrease) 615 (2,793)  
Book value, ending balance 16,685 14,054 15,040
Domestic [member] | Pocheon-Hwado Highway Corp. [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 14,834 23,998  
Share of profits (losses) 2,360 (9,164)  
Book value, ending balance 17,194 14,834 23,998
Domestic [member] | CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 12,401 13,967  
Share of profits (losses) (306) (384)  
Other increase (decrease) 1 (1,182)  
Book value, ending balance 12,096 12,401 13,967
Domestic [member] | PCC Amberstone Private Equity Fund 1 [Member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 6,181 8,904  
Acquisition 0 175  
Dividends (227) (490)  
Share of profits (losses) (469) (484)  
Other increase (decrease) (2,694) (1,924)  
Book value, ending balance 2,791 6,181 8,904
Domestic [member] | POSCO MC MATERIALS [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 153,839 155,748  
Dividends (3,000) (1,800)  
Share of profits (losses) (5,072) 403  
Other increase (decrease) 271 (512)  
Book value, ending balance 146,038 153,839 155,748
Domestic [member] | Other associates and joint ventures One [Member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 132,730 150,985  
Acquisition 25,597 12,362  
Dividends (2,216) (4,999)  
Share of profits (losses) (2,445) (6,802)  
Other increase (decrease) (6,602) (18,816)  
Book value, ending balance 147,064 132,730 150,985
Foreign [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 3,974,439 4,227,409  
Acquisition 170,173 259,959  
Dividends (367,871) (492,907)  
Share of profits (losses) 382,057 (234,076)  
Other increase (decrease) 55,424 214,054  
Book value, ending balance 4,214,222 3,974,439 4,227,409
Foreign [member] | Roy Hill Holdings Pty Ltd. [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 1,397,824 1,400,009  
Dividends (213,794) (284,541)  
Share of profits (losses) 161,274 203,130  
Other increase (decrease) 96,072 79,226  
Book value, ending balance 1,441,376 1,397,824 1,400,009
Foreign [member] | POSCO-NPS Niobium LLC [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 477,898 419,192  
Dividends (44,955) (29,225)  
Share of profits (losses) 43,229 29,336  
Other increase (decrease) (9,680) 58,595  
Book value, ending balance 466,492 477,898 419,192
Foreign [member] | KOBRASCO [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 119,820 99,768  
Dividends (22,955) (5,761)  
Share of profits (losses) 17,761 37,914  
Other increase (decrease) 12,317 (12,101)  
Book value, ending balance 126,943 119,820 99,768
Foreign [member] | BX STEEL POSCO Cold Rolled Sheet Co., Ltd. [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 126,906 111,001  
Dividends (11,440) (10,772)  
Share of profits (losses) 15,399 14,207  
Other increase (decrease) 1,751 12,470  
Book value, ending balance 132,616 126,906 111,001
Foreign [member] | DMSA/AMSA [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance   16,572  
Share of profits (losses)   (17,299)  
Other increase (decrease)   727  
Book value, ending balance     16,572
Foreign [member] | PT NICOLE METAL INDUSTRY [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 578,604 284,351  
Acquisition 62,574 247,824  
Share of profits (losses) 19,497 (315)  
Other increase (decrease) (11,213) 46,744  
Book value, ending balance 649,462 578,604 284,351
Foreign [member] | HBIS-POSCO Automotive Steel Co.,Ltd      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 179,841 208,765  
Share of profits (losses) (47,669) (49,480)  
Other increase (decrease) 2,232 20,556  
Book value, ending balance 134,404 179,841 208,765
Foreign [member] | M RES NSW HCC II Pty Ltd [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Acquisition 104,511    
Share of profits (losses) (2,210)    
Other increase (decrease) (417)    
Book value, ending balance 101,884    
Foreign [member] | South-East Asia Gas Pipeline Company Ltd. [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 279,349 287,282  
Dividends (37,273) (64,208)  
Share of profits (losses) 57,362 45,923  
Other increase (decrease) (36,063) 10,352  
Book value, ending balance 263,375 279,349 287,282
Foreign [member] | AES Mong Duong Power Company Limited [Member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance   230,699  
Dividends   (34,821)  
Share of profits (losses)   (82,075)  
Other increase (decrease)   (113,803)  
Book value, ending balance     230,699
Foreign [member] | 9404-5515 Quebec Inc. [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 426,276 346,724  
Dividends (21,180) (17,764)  
Share of profits (losses) 12,359 35,241  
Other increase (decrease) (5,853) 62,075  
Book value, ending balance 411,602 426,276 346,724
Foreign [member] | AMCI (WA) PTY LTD [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 68,478 60,225  
Share of profits (losses) 95,188 (5,127)  
Other increase (decrease) (1,060) 13,380  
Book value, ending balance 162,606 68,478 60,225
Foreign [member] | NCR LLC [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance   253,121  
Acquisition   4,275  
Share of profits (losses)   (266,425)  
Other increase (decrease)   9,029  
Book value, ending balance     253,121
Foreign [member] | KOREA LNG LTD. [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 25,622 58,759  
Dividends (5,040) (17,829)  
Share of profits (losses) 5,192 17,714  
Other increase (decrease) (6,250) (33,022)  
Book value, ending balance 19,524 25,622 58,759
Foreign [member] | Nickel mining company SAS [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance   87,967  
Share of profits (losses)   (94,353)  
Other increase (decrease)   6,386  
Book value, ending balance     87,967
Foreign [member] | Zhejiang Huayou Posco Esm Co Ltd [Member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance   105,300  
Share of profits (losses)   (117,143)  
Other increase (decrease)   11,843  
Book value, ending balance     105,300
Foreign [member] | PT. Wampu Electric Power [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 17,680 15,632  
Dividends (1,708) (1,764)  
Share of profits (losses) 739 1,238  
Other increase (decrease) (228) 2,574  
Book value, ending balance 16,483 17,680 15,632
Foreign [member] | POS-SeAH Steel Wire(Nantong) Co., Ltd. [Member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 10,713 8,642  
Share of profits (losses) 983 573  
Other increase (decrease) 298 1,498  
Book value, ending balance 11,994 10,713 8,642
Foreign [member] | Other associates and joint ventures [member]      
Disclosure of investments in associates and joint ventures [Line Items]      
Book value, beginning balance 265,428 233,400  
Acquisition 3,088 7,860  
Dividends (9,526) (26,222)  
Share of profits (losses) 2,953 12,865  
Other increase (decrease) 13,518 37,525  
Book value, ending balance ₩ 275,461 ₩ 265,428 ₩ 233,400