Defined Benefit Liabilities (Assets) - Changes in Plan Assets (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of fair value of plan assets [line items]
Interest income	₩ (3,997)	₩ (2,170)	₩ (3,615)
Plan assets [member]
Disclosure of fair value of plan assets [line items]
Beginning balance	663,617	555,175
Interest income	19,134	13,821
Remeasurement	(7,659)	(5,540)
Contributions	166,624	155,834
Benefit paid	(43,549)	(60,006)
Business combinations	21,417
Others	(2,885)	4,333
Ending balance	₩ 816,699	₩ 663,617	₩ 555,175

The decrease (increase) in the net defined benefit liability (asset) resulting from contributions to a defined benefit plan. [Refer: Net defined benefit liability (asset); Defined benefit plans [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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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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- Definition

The decrease (increase) in a net defined benefit liability (asset) resulting from the remeasurement of that net defined benefit liability (asset). [Refer: Net defined benefit liability (asset)]

+ References

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- Definition

The increase (decrease) in the net defined benefit liability (asset) resulting from business combinations and disposals. [Refer: Business combinations [member]; Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

The increase (decrease) in the net defined benefit liability (asset) resulting from changes that the entity does not separately disclose in the same statement or note. [Refer: Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

The increase (decrease) in the net defined benefit liability (asset) resulting from the passage of time. [Refer: Interest expense; Net defined benefit liability (asset)]

+ References

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- Definition

The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [member]]

+ References

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- Definition

The decrease (increase) in the net defined benefit liability (asset) resulting from payments from the plan. [Refer: Net defined benefit liability (asset)]

+ References

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