XML 139 R155.htm IDEA: XBRL DOCUMENT v3.20.1
Provision for post-employment benefits - Life Expectancies For Defined Benefit Pension Plans (Detail)
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Years life expectancy after age 65 - Current pensioners (at age 65) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 22 years 2 months 12 days 22 years 2 months 12 days
Years life expectancy after age 65 - Current pensioners (at age 65) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 23 years 8 months 12 days 23 years 10 months 24 days
Years life expectancy after age 65 - Future pensioners (current age 45) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 23 years 9 months 18 days 24 years
Years life expectancy after age 65 - Future pensioners (current age 45) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 25 years 4 months 24 days 25 years 8 months 12 days
North America [member] | Years life expectancy after age 65 - Current pensioners (at age 65) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 21 years 10 months 24 days  
North America [member] | Years life expectancy after age 65 - Current pensioners (at age 65) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 23 years 3 months 18 days  
North America [member] | Years life expectancy after age 65 - Future pensioners (current age 45) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 23 years 4 months 24 days  
North America [member] | Years life expectancy after age 65 - Future pensioners (current age 45) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 24 years 10 months 24 days  
United Kingdom [member] | Years life expectancy after age 65 - Current pensioners (at age 65) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 23 years 1 month 6 days  
United Kingdom [member] | Years life expectancy after age 65 - Current pensioners (at age 65) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 24 years 1 month 6 days  
United Kingdom [member] | Years life expectancy after age 65 - Future pensioners (current age 45) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 24 years 8 months 12 days  
United Kingdom [member] | Years life expectancy after age 65 - Future pensioners (current age 45) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 25 years 10 months 24 days  
Western Continental Europe [member] | Years life expectancy after age 65 - Current pensioners (at age 65) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 20 years 9 months 18 days  
Western Continental Europe [member] | Years life expectancy after age 65 - Current pensioners (at age 65) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 23 years 10 months 24 days  
Western Continental Europe [member] | Years life expectancy after age 65 - Future pensioners (current age 45) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 23 years 2 months 12 days  
Western Continental Europe [member] | Years life expectancy after age 65 - Future pensioners (current age 45) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 26 years  
Asia Pacific, Latin America, Africa & Middle East and Central & Eastern Europe [member] | Years life expectancy after age 65 - Current pensioners (at age 65) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 14 years  
Asia Pacific, Latin America, Africa & Middle East and Central & Eastern Europe [member] | Years life expectancy after age 65 - Current pensioners (at age 65) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 17 years 4 months 24 days  
Asia Pacific, Latin America, Africa & Middle East and Central & Eastern Europe [member] | Years life expectancy after age 65 - Future pensioners (current age 45) - male [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 14 years  
Asia Pacific, Latin America, Africa & Middle East and Central & Eastern Europe [member] | Years life expectancy after age 65 - Future pensioners (current age 45) - female [member]    
Disclosure of defined benefit plans [line items]    
Actuarial assumption of life expectancy 17 years 4 months 24 days