XML 187 R175.htm IDEA: XBRL DOCUMENT v3.20.4
Authorised and issued share capital - Summary of Authorised and Issued Share Capital (Detail)
£ in Millions
 12 Months Ended
Dec. 31, 2019
GBP (£)
shares
Dec. 31, 2018
GBP (£)
shares
Dec. 31, 2017
GBP (£)
shares
Dec. 31, 2016
GBP (£)
shares
Disclosure of classes of share capital [line items]        
Issued and fully paid capital, Beginning balance [1] £ 133.3 £ 133.3    
Share cancellations [1] (47.7)      
Issued and fully paid capital, Ending balance [1] £ 132.8 £ 133.3 £ 133.3  
Ordinary shares [member]        
Disclosure of classes of share capital [line items]        
Equity ordinary shares, authorised | shares 1,750,000,000 1,750,000,000 1,750,000,000 1,750,000,000
Nominal value of Authorised shares £ 175.0 £ 175.0 £ 175.0 £ 175.0
Number of shares issued and fully paid, Beginning balance | shares 1,332,678,227 1,332,511,552 1,331,880,730  
Exercise of share options | shares 75,625 166,675 630,822  
Share cancellations | shares (4,586,039)      
Number of shares issued and fully paid, Ending balance | shares 1,328,167,813 1,332,678,227 1,332,511,552  
Issued and fully paid capital, Beginning balance £ 133.3 £ 133.3 £ 133.2  
Exercise of share options     0.1  
Share cancellations (0.5)      
Issued and fully paid capital, Ending balance £ 132.8 £ 133.3 £ 133.3  
[1] Figures have been restated, as described in the accounting policies.