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v3.19.1

Critical Accounting Estimates and Assumptions - Additional Information (Detail) | 12 Months Ended
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Dec. 31, 2018
Bottom of range [member] |
Disclosure of changes in accounting estimates [line items] |
Amortization term of contract assets and contract liabilities | 20 months
Top of range [member] |
Disclosure of changes in accounting estimates [line items] |
Amortization term of contract assets and contract liabilities | 34 months

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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Definition Amortization term of contract assets and contract liabilities. + References No definition available. + Details
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Namespace Prefix: | kt_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |