XML 203 R191.htm IDEA: XBRL DOCUMENT v3.19.1

Earnings per Share - Summary of Basic and Diluted Earnings per Share from Operations (Detail) - KRW (₩) ₩ / shares in Units, ₩ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic earnings per share [abstract]
Profit (loss) attributable to ordinary shares	₩ 645,571	₩ 461,559	₩ 745,090
Weighted average number of ordinary shares outstanding	245,049,466	245,017,175	244,892,313
Basic earnings per share (In Korean won)	₩ 2,634	₩ 1,884	₩ 3,043
Profit attributable to ordinary shares (In millions of Korean won)	₩ 645,571	₩ 461,559	₩ 745,090
Adjusted net income attributable to ordinary shares (In millions of Korean won)			(67)
Diluted profit attributable to ordinary shares (In millions of Korean won)	₩ 645,571	₩ 461,559	₩ 745,023
Number of dilutive potential ordinary shares outstanding	1,163	79,880	84,245
Weighted average number of ordinary shares outstanding	245,050,629	245,097,055	244,976,558
Diluted earnings per share (In Korean won)	₩ 2,634	₩ 1,883	₩ 3,041

X

- Definition

The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2018-01-01
-Paragraph 70
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=33&date=2018-03-01&anchor=para_70_b&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_AdjustedWeightedAverageShares
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator) divided by the weighted average number of ordinary shares outstanding during the period (the denominator).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2018-01-01
-Paragraph 66
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=33&date=2018-03-01&anchor=para_66&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_BasicEarningsLossPerShare
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	ifrs-full_BasicEarningsPerShareAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2018-01-01
-Paragraph 66
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=33&date=2018-03-01&anchor=para_66&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_DilutedEarningsLossPerShare
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The profit (loss) attributable to ordinary equity holders of the parent equity. [Refer: Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2018-01-01
-Paragraph 70
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=33&date=2018-03-01&anchor=para_70_a&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_ProfitLossAttributableToOrdinaryEquityHoldersOfParentEntity
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The profit (loss) attributable to ordinary equity holders of the parent equity, adjusted for the effects of all dilutive potential ordinary shares. [Refer: Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2018-01-01
-Paragraph 70
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=33&date=2018-03-01&anchor=para_70_a&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_ProfitLossAttributableToOrdinaryEquityHoldersOfParentEntityIncludingDilutiveEffects
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Adjusted net income attributable to ordinary shares.

+ References

No definition available.

+ Details

Name:	kt_AdjustedNetIncomeAttributableToOrdinaryShares
Namespace Prefix:	kt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Weighted average number of shares basic.

+ References

No definition available.

+ Details

Name:	kt_WeightedAverageNumberOfSharesBasic
Namespace Prefix:	kt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Weighted average number of shares dilutive.

+ References

No definition available.

+ Details

Name:	kt_WeightedAverageNumberOfSharesDilutive
Namespace Prefix:	kt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration