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Business Combination - Additional Information (Detail) ₩ in Millions | 1 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2018 KRW (₩) shares | Dec. 31, 2018 KRW (₩) | Dec. 31, 2017
CJ ENM CO., Ltd [member] |  |  |
Disclosure of detailed information about business combination [Line Items] |  |  |
Percentage of ownership interest | 100.00% |  |
Number of shares acquired | shares | 1,600,000 |  |
SG Safety Corporation [member] |  |  |
Disclosure of detailed information about business combination [Line Items] |  |  |
Consideration | ₩ 27,570 | ₩ 27,544 |
MOS GB Co.,Ltd and MOS Chungcheong Co., Ltd., [member] |  |  |
Disclosure of detailed information about business combination [Line Items] |  |  |
Consideration | ₩ 11,048 |  |
CJ Digital Music Co., Ltd. [member] |  |  |
Disclosure of detailed information about business combination [Line Items] |  |  |
Consideration |  | ₩ 50,948 |
GENIE Music Corporation K T Music Corporation [member] |  |  |
Disclosure of detailed information about business combination [Line Items] |  |  |
Percentage of ownership interest |  | 36.00% | 42.50%
GENIE Music Corporation K T Music Corporation [member] | CJ Digital Music Co., Ltd. [member] | CJ ENM CO., Ltd [member] |  |  |
Disclosure of detailed information about business combination [Line Items] |  |  |
Number of shares issued | 8,922,685 |  |

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