XML 178 R166.htm IDEA: XBRL DOCUMENT
v3.19.1

Retained Earnings - Summary of Retained Earnings (Parenthetical) (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2017
Miscellaneous equity [abstract] |
Minimum percentage of cash dividend declared appropriation to legal reserve | 10.00%
Percentage of legal reserve equal to capital stock issued | 50.00%

X
- References No definition available. + Details
Name: | ifrs-full_MiscellaneousEquityAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum percentage of cash dividend declared appropriation to legal reserve. + References No definition available. + Details
Name: | kt_MinimumPercentageOfCashDividendDeclaredAppropriationToLegalReserve
Namespace Prefix: | kt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of legal reserves equal to capital stock. + References No definition available. + Details
Name: | kt_PercentageOfLegalReservesEqualToCapitalStock
Namespace Prefix: | kt_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration