End date of current fiscal year in the format --MM-DD.

No definition available.

Name:	dei_CurrentFiscalYearEndDate
Namespace Prefix:	dei_
Data Type:	xbrli:gMonthDayItemType
Balance Type:	na
Period Type:	duration

- Definition

The description of the nature of the entity's operations and principal activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 138
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_138_b&doctype=Standard
-URIDate 2019-03-27

+ Details

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

- Definition

The amount of investments accounted for using the equity method. The equity method is a method of accounting whereby the investment is initially recognised at cost and adjusted thereafter for the post-acquisition change in the investor's share of net assets of the investee. The investor's profit or loss includes its share of the profit or loss of the investee. The investor's other comprehensive income includes its share of the other comprehensive income of the investee. [Refer: At cost [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2019-01-01
-Paragraph 24
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_24_a&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2019-01-01
-Paragraph B16
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2019-en-r&anchor=para_B16&doctype=Appendix&subtype=B
-URIDate 2019-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 54
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_54_e&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_InvestmentAccountedForUsingEquityMethod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The principal place of business of an associate. [Refer: Principal place of business; Associates [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2019-01-01
-Paragraph 16
-Subparagraph b
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2019-en-r&anchor=para_16_b_ii&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2019-01-01
-Paragraph 17
-Subparagraph b
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2019-en-r&anchor=para_17_b_ii&doctype=Standard
-URIDate 2019-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2019-01-01
-Paragraph 21
-Subparagraph a
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2019-en-r&anchor=para_21_a_iii&doctype=Standard
-URIDate 2019-03-27

+ Details

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

- Definition

The proportion of ownership interest in an associate attributable to the entity. [Refer: Associates [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2019-01-01
-Paragraph 17
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2019-en-r&anchor=para_17_b_iii&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2019-01-01
-Paragraph 16
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2019-en-r&anchor=para_16_b_iii&doctype=Standard
-URIDate 2019-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2019-01-01
-Paragraph 21
-Subparagraph a
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2019-en-r&anchor=para_21_a_iv&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_ProportionOfOwnershipInterestInAssociate
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Date of incorporation of associate.

+ References

No definition available.

+ Details

Name:	lpl_DateOfIncorporationOfAssociate
Namespace Prefix:	lpl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information about associate and joint ventures associated with domain members defined in one or many axes of the table.

+ References

No definition available.

+ Details

Name:	lpl_DisclosureOfAssociatesAndJointVenturesLineItems
Namespace Prefix:	lpl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_PajuElectricGlassCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_InveniaCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_WooReeEAndLCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_LbGeminiNewGrowthFundNumberSixteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_YasCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_AvatecCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_ArcticSentinelIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_CynoraGmbhMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_MaterialScienceCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=lpl_NanosysIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Investments in Equity Accounted Investees - Summary of Associates (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of associates and joint ventures [Line Items]
Fiscal year end	--12-31
Date of incorporation	2000-08
Carrying amount	₩ 109,611	₩ 113,989	₩ 122,507
Paju Electric Glass Co., Ltd. [member]
Disclosure of associates and joint ventures [Line Items]
Location	Paju, South Korea
Fiscal year end	--12-31
Date of incorporation	2005-01
Business	Manufacture glass for display
Percentage of ownership	40.00%	40.00%
Carrying amount	₩ 50,697	₩ 47,823	₩ 46,511
INVENIA Co., Ltd. (LIG INVENIA Co., Ltd.) [member]
Disclosure of associates and joint ventures [Line Items]
Location	Seongnam, South Korea
Fiscal year end	--12-31
Date of incorporation	2001-01
Business	Develop and manufacture equipment for display manufacture
Percentage of ownership		13.00%
Carrying amount		₩ 4,166
WooRee E&L Co., Ltd. [member]
Disclosure of associates and joint ventures [Line Items]
Location	Ansan, South Korea
Fiscal year end	--12-31
Date of incorporation	2008-06
Business	Manufacture LED back light unit packages
Percentage of ownership	14.00%	14.00%
Carrying amount	₩ 7,310	₩ 4,746
LB Gemini new growth fund no.16 [member]
Disclosure of associates and joint ventures [Line Items]
Fiscal year end	--12-31
YAS Co., Ltd. [member]
Disclosure of associates and joint ventures [Line Items]
Location	Paju, South Korea
Fiscal year end	--12-31
Date of incorporation	2002-04
Business	Develop and manufacture deposition equipment for OLEDs
Percentage of ownership	15.00%	15.00%
Carrying amount	₩ 19,424	₩ 16,308
AVATEC Co., Ltd. [member]
Disclosure of associates and joint ventures [Line Items]
Location	Daegu, South Korea
Fiscal year end	--12-31
Date of incorporation	2000-08
Business	Process and sell glass for display
Percentage of ownership	14.00%	17.00%
Carrying amount	₩ 19,929	₩ 23,441
Arctic Sentinel, Inc. (Fuhu, Inc.) [member]
Disclosure of associates and joint ventures [Line Items]
Location	Los Angeles, U.S.A.
Fiscal year end	--03-31
Date of incorporation	2008-06
Business	Develop and manufacture tablet for kids
Percentage of ownership	10.00%	10.00%
Cynora GmbH [member]
Disclosure of associates and joint ventures [Line Items]
Location	Bruchsal, Germany
Fiscal year end	--12-31
Date of incorporation	2003-03
Business	Develop organic emitting materials for displays and lighting devices
Percentage of ownership	12.00%	14.00%
Carrying amount	₩ 4,714	₩ 8,668
Material Science Co Ltd [member]
Disclosure of associates and joint ventures [Line Items]
Location	Seoul, South Korea
Fiscal year end	--12-31
Date of incorporation	2014-01
Business	Develop, manufacture, and sell materials for display
Percentage of ownership	10.00%	10.00%
Carrying amount	₩ 2,354	₩ 3,346
Nanosys Inc [member]
Disclosure of associates and joint ventures [Line Items]
Location	Milpitas, U.S.A.
Fiscal year end	--12-31
Date of incorporation	2001-07
Business	Develop, manufacture, and sell materials for display
Percentage of ownership	4.00%	4.00%
Carrying amount	₩ 5,183	₩ 5,491