XML 95 R123.htm IDEA: XBRL DOCUMENT v3.20.2
Share Capital - Summary of Share Capital (Parenthetical) (Detail)
$ / shares in Units, $ in Millions
 1 Months Ended 2 Months Ended 12 Months Ended
Dec. 31, 2018
USD ($)
Sep. 03, 2020
shares
Jun. 30, 2020
$ / shares
shares
Jun. 30, 2019
USD ($)
$ / shares
shares
Jun. 30, 2018
$ / shares
shares
Jun. 30, 2020
£ / shares
Jun. 30, 2019
£ / shares
Jun. 30, 2018
£ / shares
Disclosure of classes of share capital [line items]                
Off-market buy-back program | $ $ 5,200     $ 5,220        
BHP Group Limited [member]                
Disclosure of classes of share capital [line items]                
Par value | $ / shares     $ 0.50          
Number of ordinary shares issued on the exercise of awards     6,893,113 5,902,588 7,339,522      
BHP Group Limited [member] | Major ordinary share transactions [member]                
Disclosure of classes of share capital [line items]                
Number of ordinary shares issued on the exercise of awards   0            
BHP Group Plc [member]                
Disclosure of classes of share capital [line items]                
Par value | $ / shares     $ 0.50          
Number of ordinary shares issued on the exercise of awards     222,245 275,984 711,705      
BHP Group Plc [member] | Major ordinary share transactions [member]                
Disclosure of classes of share capital [line items]                
Number of ordinary shares issued on the exercise of awards   0            
Special Voting share of US$0.50 par value [member] | BHP Group Plc [member]                
Disclosure of classes of share capital [line items]                
Par value | $ / shares     $ 0.50 $ 0.50 $ 0.50      
5.5% Preference shares [member]                
Disclosure of classes of share capital [line items]                
Par value | £ / shares           £ 1 £ 1 £ 1
Dividend rate percentage     5.50% 5.50% 5.50%      
5.5% Preference shares [member] | BHP Group Plc [member]                
Disclosure of classes of share capital [line items]                
Par value | £ / shares           £ 1 £ 1 £ 1
Dividend rate percentage     5.50% 5.50% 5.50%