v3.26.3
Property, Plant and Equipment & Natural Gas Properties - Oil and Gas, Capitalized Exploratory Well Cost, Roll Forward (Details) - Unproved properties - USD ($)
$ in Thousands
 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Oil and Gas, Capitalized Exploratory Well Cost [Roll Forward]    
Balance at the beginning of the year $ 342,314 $ 230,119
Additions through asset acquisitions 287,049  
Capital expenditure 149,291 102,937
Restoration assets 136 524
Interest on finance lease liability and related depreciation of ROU assets capitalized 11,953 12,633
Disposal (444)  
Government grant (120) (6,169)
Effect of changes in foreign exchange rates 16,857 2,270
Balance at the end of the year 807,036 342,314
EP 161    
Oil and Gas, Capitalized Exploratory Well Cost [Roll Forward]    
Balance at the beginning of the year 25,091 23,744
Additions through asset acquisitions 0  
Capital expenditure 3,557 1,181
Restoration assets 0 0
Interest on finance lease liability and related depreciation of ROU assets capitalized 0 0
Disposal 0  
Government grant (66) 0
Effect of changes in foreign exchange rates 1,120 166
Balance at the end of the year 29,702 25,091
EP 136    
Oil and Gas, Capitalized Exploratory Well Cost [Roll Forward]    
Balance at the beginning of the year 45,483 51,035
Additions through asset acquisitions 0  
Capital expenditure 181 315
Restoration assets 0 0
Interest on finance lease liability and related depreciation of ROU assets capitalized 0 0
Disposal (444)  
Government grant (54) (6,169)
Effect of changes in foreign exchange rates 2,258 302
Balance at the end of the year 47,424 45,483
EP 76, 98 & 117    
Oil and Gas, Capitalized Exploratory Well Cost [Roll Forward]    
Balance at the beginning of the year 271,740 155,340
Additions through asset acquisitions 285,435  
Capital expenditure 145,553 101,441
Restoration assets 136 524
Interest on finance lease liability and related depreciation of ROU assets capitalized 11,953 12,633
Disposal 0  
Government grant 0 0
Effect of changes in foreign exchange rates 13,479 1,802
Balance at the end of the year 728,296 271,740
Mako Trough    
Oil and Gas, Capitalized Exploratory Well Cost [Roll Forward]    
Balance at the beginning of the year 0 0
Additions through asset acquisitions 1,614  
Capital expenditure 0 0
Restoration assets 0 0
Interest on finance lease liability and related depreciation of ROU assets capitalized 0 0
Disposal 0  
Government grant 0 0
Effect of changes in foreign exchange rates 0 0
Balance at the end of the year $ 1,614 $ 0