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Operating Expenses - Summary of Operating Expenses (Detail) - KRW (₩) ₩ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Profit (loss) [abstract] |  |  |
Salaries and wages | ₩ 4,215,810 | ₩ 4,123,680 | ₩ 3,974,233
Depreciation | 2,605,594 | 2,605,128 | 2,530,252
Depreciation of right-of-use assets | 398,716 | 404,175 | 442,627
Amortization of intangible assets | 603,327 | 624,982 | 656,611
Commissions | 1,125,944 | 965,461 | 1,115,477
Interconnection charges | 507,567 | 500,081 | 534,025
International interconnection fee | 192,008 | 172,529 | 240,254
Purchase of inventories | 3,753,792 | 3,681,801 | 4,453,820
Changes of inventories | 20,491 | 257,041 | 282,957
Sales commission | 2,343,375 | 2,337,127 | 2,315,731
Service cost | 2,296,324 | 2,102,875 | 1,610,261
Utilities | 364,373 | 360,797 | 332,816
Taxes and dues | 268,651 | 283,197 | 277,742
Rent | 123,246 | 136,355 | 193,357
Insurance premium | 66,717 | 71,018 | 82,404
Installation fee | 154,542 | 132,117 | 155,178
Advertising expenses | 171,400 | 132,466 | 150,166
Research and development expenses | 168,969 | 156,940 | 165,028
Card service cost | 3,114,047 | 2,941,669 | 3,066,766
Loss on disposal of property and equipment | 71,417 | 75,879 | 71,233
Loss on disposal of intangible assets | 3,885 | 3,207 | 5,965
Loss on disposal of right-of-use assets | 11,457 | 7,844 | 4,502
Direct cost of government subsidies | 42,732 | 31,447 | 23,248
Loss on disposal of investments in subsidiaries | 13,727 | 0 | 7,586
Impairment loss on property and equipment | 2,115 | 79,775 | 43,260
Impairment loss on intangible assets | 3,747 | 211,637 | 61,899
Donations | 10,981 | 20,745 | 98,659
Other allowance for bad debts | 28,066 | 51,333 | 26,372
Others | 823,242 | 947,008 | 949,790
Total | ₩ 23,506,262 | ₩ 23,418,314 | ₩ 23,872,219

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- Definition The amount of amortisation expense. Amortisation is the systematic allocation of depreciable amounts of intangible assets over their useful lives. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_112_c&doctype=Standard -URIDate 2021-03-24 + Details
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- Definition The amount of depreciation expense. Depreciation is the systematic allocation of depreciable amounts of tangible assets over their useful lives. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_112_c&doctype=Standard -URIDate 2021-03-24 + Details
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- Definition The amount of expense arising from donations and subsidies. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_112_c&doctype=Standard -URIDate 2021-03-24 + Details
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- Definition The amount of impairment loss recognised in profit or loss for property, plant and equipment. [Refer: Impairment loss recognised in profit or loss; Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2021-01-01 -Paragraph 73 -Subparagraph e -Clause v -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_73_e_v&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 98 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_98_a&doctype=Standard -URIDate 2021-03-24 + Details
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- Definition The amount of expense arising from purchased insurance. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_112_c&doctype=Standard -URIDate 2021-03-24 + Details
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