v3.26.1
Property and Equipment - Summary of Property and Equipment (Detail) - KRW (₩)
₩ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment ₩ 11,902,173 ₩ 12,617,394 ₩ 13,006,196
Acquisition cost [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 47,597,637 47,188,174  
Accumulated depreciation [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (35,680,781) (34,556,379)  
Accumulated impairment loss [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (14,683) (14,401)  
Land [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 1,319,260 1,260,712 1,248,200
Land [member] | Acquisition cost [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 1,319,260 1,260,712  
Buildings and structures [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 892,732 765,818 773,392
Buildings and structures [member] | Acquisition cost [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 2,041,946 1,822,695  
Buildings and structures [member] | Accumulated depreciation [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (1,148,764) (1,056,427)  
Buildings and structures [member] | Accumulated impairment loss [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (450) (450)  
Structures [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 185,826 210,987 234,879
Structures [member] | Acquisition cost [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 965,034 955,360  
Structures [member] | Accumulated depreciation [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (777,607) (742,772)  
Structures [member] | Accumulated impairment loss [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (1,601) (1,601)  
Machinery [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 7,334,543 7,722,566 7,890,654
Machinery [member] | Acquisition cost [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 38,731,865 38,191,687  
Machinery [member] | Accumulated depreciation [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (31,385,515) (30,457,696)  
Machinery [member] | Accumulated impairment loss [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (11,807) (11,425)  
Other      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 284,284 369,007 485,157
Other | Acquisition cost [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 1,466,321 1,631,503  
Other | Accumulated depreciation [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (1,181,476) (1,262,496)  
Other | Accumulated impairment loss [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (561)    
Rights-of-use assets [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 1,372,525 1,608,219  
Rights-of-use assets [member] | Acquisition cost [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 2,559,944 2,645,207  
Rights-of-use assets [member] | Accumulated depreciation [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment (1,187,419) (1,036,988)  
Rights-of-use assets [member] | Accumulated impairment loss [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 0    
Construction in progress [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 513,003 680,085 ₩ 761,963
Construction in progress [member] | Acquisition cost [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment 513,267 681,010  
Construction in progress [member] | Accumulated impairment loss [member]      
Disclosure of detailed information about property, plant and equipment [line items]      
Property and equipment ₩ (264) ₩ (925)