v3.10.0.1
Contingent Liabilities and Legal Proceedings - Additional Information (Detail)
₨ / shares in Units, € in Millions, £ in Millions, $ in Millions, ₨ in Billions
 6 Months Ended 12 Months Ended
Dec. 31, 2018
GBP (£)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
GBP (£)
Petition
Dec. 31, 2017
USD ($)
Petition
Jun. 30, 2015
GBP (£)
Jun. 30, 2015
USD ($)
Jun. 30, 2014
GBP (£)
shares
Jun. 30, 2014
USD ($)
shares
Jun. 30, 2014
GBP (£)
₨ / shares
Jun. 30, 2013
Dec. 31, 2018
EUR (€)
Dec. 31, 2017
USD ($)
Oct. 31, 2017
GBP (£)
Jun. 30, 2014
INR (₨)
Disclosure of contingent liabilities [line items]                            
Ownership Interest in subsidiary 100.00% 100.00% 100.00% 100.00%                    
United Spirits Limited [member]                            
Disclosure of contingent liabilities [line items]                            
Shares percentage of additional equivalent payments required to be made to shareholders     0.04% 0.04%                    
Diageo Holdings Netherlands BV [member] | Watson Limited [member] | Standard Chartered Bank (SCB) [member]                            
Disclosure of contingent liabilities [line items]                            
Facility payment under guarantee agreement         £ 96 $ 141                
UBHL [member] | United Spirits Limited [member]                            
Disclosure of contingent liabilities [line items]                            
Acquisition price per share | ₨ / shares                 ₨ 1,440          
SPA [member] | United Spirits Limited [member]                            
Disclosure of contingent liabilities [line items]                            
Date of acquisition                   Nov. 09, 2012        
Business acquisition number of shares acquired | shares             21,767,749 21,767,749            
Business acquisition, percentage of interest acquired             14.98%   14.98%         14.98%
Total consideration             £ 349   ₨ 349         ₨ 31.3
Ownership Interest in subsidiary         54.78% 54.78%                
Ownership interest by external party         2.38% 2.38%                
Completion date of original acquisition             Jul. 04, 2013 Jul. 04, 2013            
SPA [member] | UBHL [member]                            
Disclosure of contingent liabilities [line items]                            
Number of pending winding-up petitions | Petition     5 5                    
SPA [member] | UBHL [member] | United Spirits Limited [member]                            
Disclosure of contingent liabilities [line items]                            
Business acquisition number of shares acquired | shares             10,141,437 10,141,437            
Business acquisition, percentage of interest acquired             6.98%   6.98%         6.98%
Contingent Liability for Guarantees [member] | Diageo Holdings Netherlands BV [member] | Watson Limited [member] | Standard Chartered Bank (SCB) [member]                            
Disclosure of contingent liabilities [line items]                            
Guarantee provided in respect of bank facility             £ 92 $ 135            
Tax Contingent Liability [member] | France [member]                            
Disclosure of contingent liabilities [line items]                            
Interest and penalties £ 214                   € 241      
Tax Contingent Liability [member] | Maximum [member]                            
Disclosure of contingent liabilities [line items]                            
Interest and penalties                         £ 278  
Tax Contingent Liability [member] | Maximum [member] | Brazil [member]                            
Disclosure of contingent liabilities [line items]                            
Interest and penalties 260                          
Tax Contingent Liability [member] | Maximum [member] | India [member]                            
Disclosure of contingent liabilities [line items]                            
Interest and penalties 130                          
25 February agreement [member] | Watson Limited [member]                            
Disclosure of contingent liabilities [line items]                            
Claim or damages related to breach of associated security documents     £ 96 $ 141                    
Damages related to breach of associated security documents     £ 105 $ 142                    
Percentage of damages claimed     50.00% 50.00%                    
25 February agreement [member] | Dr Mallya [member]                            
Disclosure of contingent liabilities [line items]                            
Payment relating to disengagement agreements     £ 53 $ 75                    
Global non-compete, non-interference, non-solicitation and standstill commitments term     5 years 5 years                    
Consideration payment period     5 years 5 years                    
Agreement date     Feb. 25, 2016 Feb. 25, 2016                    
Payment relating to disengagement agreements     £ 28 $ 40                    
Amount payable in equal installments to Dr Mallya     5                 $ 7    
Installment not liable to pay related to breaches of several provisions     5 7                    
Demanding the repayment of original amount paid £ 28 $ 40 28 $ 40                    
Counter claim payment     5                 $ 7    
25 February agreement [member] | United Breweries Overseas Limited [member]                            
Disclosure of contingent liabilities [line items]                            
Claim or damages related to breach of associated security documents     £ 30