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Trade and Other Receivables - Summary of Changes in Allowance for Doubtful Accounts (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of financial assets [line items]
Provision	₩ 523,799
Trade receivables [member]
Disclosure of financial assets [line items]
Beginning balance	470,871	₩ 468,741	₩ 527,617
Provision	38,888	84,975	95,489
Reversal or written-off	(70,121)	(80,518)	(135,318)
Changes in the scope of consolidation	(107)	215	(16,752)
Others	(104)	(2,542)	2,232
Ending balance	439,427	470,871	468,741
Other receivables [member]
Disclosure of financial assets [line items]
Beginning balance	141,616	250,842	311,082
Provision	5,809	7,736	46,066
Reversal or written-off	(61,220)	(108,638)	(33,282)
Changes in the scope of consolidation	(35)	56	(69,732)
Others	(1,798)	(8,380)	(3,272)
Ending balance	₩ 84,372	₩ 141,616	₩ 250,842

X

- Definition

The amount of additional allowance for credit losses of financial assets recognised in profit or loss. [Refer: Allowance account for credit losses of financial assets]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2018-01-01
-Name IFRS
-Number 7
-IssueDate 2017-01-01
-Paragraph 16
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_16&doctype=Standard&book=B
-URIDate 2017-03-09

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X

- Definition

The amount of an allowance account used to record impairments to financial assets due to credit losses. [Refer: Financial assets]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2018-01-01
-Name IFRS
-Number 7
-IssueDate 2017-01-01
-Paragraph 16
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_16&doctype=Standard&book=B
-URIDate 2017-03-09

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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.

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X

- Definition

The increase (decrease) in allowance account for credit losses of financial assets resulting from changes that the entity does not separately disclose in the same statement or note. [Refer: Allowance account for credit losses of financial assets]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2018-01-01
-Name IFRS
-Number 7
-IssueDate 2017-01-01
-Paragraph 16
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_16&doctype=Standard&book=B
-URIDate 2017-03-09

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- Definition

Allowance for doubtful accounts changes in the scope of consolidation.

+ References

No definition available.

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- Definition

Reversal or write off allowance account for credit losses of financial assets.

+ References

No definition available.

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