|**Segment, Geographic and Other Revenue Information - Revenues By Geographic Area (Detail) - USD ($) $ in Millions**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 3 Months Ended                                                                                                                                                                                                             
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                            
|Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | [1]                                                                                                                                                                                                                        
|Percentage Change In Revenue                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                            
|U.S. [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                            
|**Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                            
|Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                            
|Percentage Change In Revenue                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                            
|Developed Europe [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                            
|**Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                            
|Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | [2]                                                                                                                                                                                                                        
|Percentage Change In Revenue                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | [2]                                                                                                                                                                                                                        
|Developed Rest Of World [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                            
|**Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                            
|Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | [3]                                                                                                                                                                                                                        
|Percentage Change In Revenue                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | [3]                                                                                                                                                                                                                        
|Emerging Markets [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                            
|**Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                            
|Revenues                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | [4]                                                                                                                                                                                                                        
|Percentage Change In Revenue                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | [4]                                                                                                                                                                                                                        
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
|[1]
Amounts may not add due to rounding.[2]
Developed Europe region includes the following markets: Western Europe, Scandinavian countries and Finland.Revenues denominated in euros were$1.5 billionin thefirst quarterof2020and$1.7 billionin thefirst quarterof2019.[3]
Developed Rest of World region includes the following markets: Japan, Canada, South Korea, Australia and New Zealand.[4]
Emerging Markets region includes, but is not limited to, the following markets: Asia (excluding Japan and South Korea), Latin America, Eastern Europe, Africa, the Middle East, Central Europe and Turkey. | [1]                                                                                                                                                                                                                        
|[1]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | Amounts may not add due to rounding.                                                                                                                                                                                       
|[2]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | Developed Europe region includes the following markets: Western Europe, Scandinavian countries and Finland.Revenues denominated in euros were$1.5 billionin thefirst quarterof2020and$1.7 billionin thefirst quarterof2019.
|[3]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | Developed Rest of World region includes the following markets: Japan, Canada, South Korea, Australia and New Zealand.                                                                                                      
|[4]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | Emerging Markets region includes, but is not limited to, the following markets: Asia (excluding Japan and South Korea), Latin America, Eastern Europe, Africa, the Middle East, Central Europe and Turkey.                 

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