XML 64 R52.htm IDEA: XBRL DOCUMENT
v3.25.1

SHARE CAPITAL AND SHARE PREMIUM - Summary of Movements in the Company's Share Capital and Share Premium (Details) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2025 USD ($) shares
Share Capital [Roll Forward] |
Beginning balance | $ 2,696,013
Exercise of share options | 2,373
Reclassification of vesting of restricted share units | 14,495
Ending balance | $ 2,712,881
Number of shares in issue |
Share Capital [Roll Forward] |
Beginning balance (in shares) | shares | 367,298,315
Exercise of share option (in shares) | shares | 286,658
Reclassification of vesting of restricted share units (in shares) | shares | 473,106
Ending balance (in shares) | shares | 368,058,079
Share capital |
Share Capital [Roll Forward] |
Beginning balance | $ 37
Exercise of share options | 0
Reclassification of vesting of restricted share units | 0
Ending balance | 37
Share premium |
Share Capital [Roll Forward] |
Beginning balance | 2,695,976
Exercise of share options | 2,373
Reclassification of vesting of restricted share units | 14,495
Ending balance | $ 2,712,844

X
- Definition Exercise of share option. + References No definition available. + Details
Name: | legn_ExerciseOfShareOption
Namespace Prefix: | legn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Exercise of share option number of shares in issue. + References No definition available. + Details
Name: | legn_ExerciseOfShareOptionNumberOfSharesInIssue
Namespace Prefix: | legn_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reclassification of vested restricted stock units, number of shares in issue. + References No definition available. + Details
Name: | legn_ReclassificationOfVestedRestrictedStockUnitsNumberOfSharesInIssue
Namespace Prefix: | legn_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reclassification of vested restricted stock units, share capital and share premium. + References No definition available. + Details
Name: | legn_ReclassificationOfVestedRestrictedStockUnitsShareCapitalAndSharePremium
Namespace Prefix: | legn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Share capital and share premium. + References No definition available. + Details
Name: | legn_ShareCapitalAndSharePremium
Namespace Prefix: | legn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Share capital and share premium, number of shares in issue. + References No definition available. + Details
Name: | legn_ShareCapitalAndSharePremiumNumberOfSharesInIssue
Namespace Prefix: | legn_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Share Capital + References No definition available. + Details
Name: | legn_ShareCapitalRollForward
Namespace Prefix: | legn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=ifrs-full_IssuedCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=legn_ShareCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=ifrs-full_SharePremiumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |