Investment properties, net (Details) - KRW (₩) ₩ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about investment property [Line Items]
Beginning balance	₩ 353,680	₩ 269,910
Depreciation	(1,176)	(678)	₩ (669)
Others	(67,790)	84,448
Endings balance	284,714	353,680	269,910
Carrying Amount Other than Government Grants [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	353,744	269,923
Depreciation	(1,178)	(679)
Others	(67,769)	84,500
Endings balance	284,797	353,744	269,923
Acquisition cost [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	365,589
Endings balance	300,370	365,589
Accumulated depreciation [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	(11,845)
Endings balance	(15,573)	(11,845)
Government grants [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	(64)	(13)
Depreciation	2	1
Others	(21)	(52)
Endings balance	(83)	(64)	(13)
Investment property - Land [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	336,421	253,960
Depreciation	0	0
Others	(72,216)	82,461
Endings balance	264,205	336,421	253,960
Investment property - Land [Member] \| Carrying Amount Other than Government Grants [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	336,421	253,960
Others	(72,216)	82,461
Endings balance	264,205	336,421	253,960
Investment property - Land [Member] \| Acquisition cost [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	336,421
Endings balance	264,205	336,421
Investment property - Buildings [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	17,259	15,950
Depreciation	(1,176)	(678)
Others	4,426	1,987
Endings balance	20,509	17,259	15,950
Investment property - Buildings [Member] \| Carrying Amount Other than Government Grants [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	17,323	15,963
Depreciation	(1,178)	(679)
Others	4,447	2,039
Endings balance	20,592	17,323	15,963
Investment property - Buildings [Member] \| Acquisition cost [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	29,168
Endings balance	36,165	29,168
Investment property - Buildings [Member] \| Accumulated depreciation [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	(11,845)
Endings balance	(15,573)	(11,845)
Investment property - Buildings [Member] \| Government grants [Member]
Disclosure of detailed information about investment property [Line Items]
Beginning balance	(64)	(13)
Depreciation	2	1
Others	(21)	(52)
Endings balance	₩ (83)	₩ (64)	₩ (13)

The amount of depreciation recognised on investment property. [Refer: Depreciation and amortisation expense; Investment property]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 40
-IssueDate 2017-01-01
-Paragraph 79
-Subparagraph d
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=40&date=2017-03-01&anchor=para_79_d_iv&doctype=Standard
-URIDate 2017-03-09

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 40
-IssueDate 2017-01-01
-Paragraph 76
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=40&date=2017-03-01&anchor=para_76&doctype=Standard
-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.

+ Details

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- Definition

The increase (decrease) in investment property resulting from changes that the entity does not separately disclose in the same statement or note. [Refer: Investment property]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 40
-IssueDate 2017-01-01
-Paragraph 79
-Subparagraph d
-Clause viii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=40&date=2017-03-01&anchor=para_79_d_viii&doctype=Standard
-URIDate 2017-03-09

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 40
-IssueDate 2017-01-01
-Paragraph 76
-Subparagraph g
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=40&date=2017-03-01&anchor=para_76_g&doctype=Standard
-URIDate 2017-03-09

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- Definition

Expiry date 2019-01-01: The amount of property (land or a building - or part of a building - or both) held (by the owner or by the lessee under a finance lease) to earn rentals or for capital appreciation or both, rather than for: (a) use in the production or supply of goods or services or for administrative purposes; or (b) sale in the ordinary course of business. Effective 2019-01-01: The amount of property (land or a building - or part of a building - or both) held (by the owner or by the lessee as a right-of-use asset) to earn rentals or for capital appreciation or both, rather than for: (a) use in the production or supply of goods or services or for administrative purposes; or (b) sale in the ordinary course of business.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 40
-IssueDate 2017-01-01
-Paragraph 76
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=40&date=2017-03-01&anchor=para_76&doctype=Standard
-URIDate 2017-03-09

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 40
-IssueDate 2017-01-01
-Paragraph 79
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=40&date=2017-03-01&anchor=para_79_d&doctype=Standard
-URIDate 2017-03-09

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 54
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_54_b&doctype=Standard
-URIDate 2017-03-09

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