v3.7.0.1
Borrowings - Carrying Value and Fair Value of Long-Term Borrowings (Detail) - USD ($)
$ in Millions
Jun. 30, 2017
Dec. 31, 2016
Debt Instrument [Line Items]    
Maturity Amount $ 4,998  
Unamortized Discount and Debt Issuance Costs (28)  
Carrying Value 4,970 $ 4,915
Fair Value 5,225 $ 5,200
5.00% Notes due 2019 [Member]    
Debt Instrument [Line Items]    
Maturity Amount 1,000  
Unamortized Discount and Debt Issuance Costs (1)  
Carrying Value 999  
Fair Value 1,074  
4.25% Notes due 2021 [Member]    
Debt Instrument [Line Items]    
Maturity Amount 750  
Unamortized Discount and Debt Issuance Costs (4)  
Carrying Value 746  
Fair Value 805  
3.375% Notes due 2022 [Member]    
Debt Instrument [Line Items]    
Maturity Amount 750  
Unamortized Discount and Debt Issuance Costs (4)  
Carrying Value 746  
Fair Value 780  
3.50% Notes due 2024 [Member]    
Debt Instrument [Line Items]    
Maturity Amount 1,000  
Unamortized Discount and Debt Issuance Costs (6)  
Carrying Value 994  
Fair Value 1,050  
1.25% Notes due 2025 [Member]    
Debt Instrument [Line Items]    
Maturity Amount 798  
Unamortized Discount and Debt Issuance Costs (6)  
Carrying Value 792  
Fair Value 809  
3.20% Notes due 2027 [Member]    
Debt Instrument [Line Items]    
Maturity Amount 700  
Unamortized Discount and Debt Issuance Costs (7)  
Carrying Value 693  
Fair Value $ 707