v3.10.0.1
Subsequent Event (Details) - USD ($)
shares in Millions
 12 Months Ended
Feb. 12, 2019
Feb. 07, 2019
Jun. 20, 2016
Mar. 10, 2016
Mar. 08, 2016
Dec. 31, 2018
Dec. 31, 2017
 [2]
Dec. 31, 2016
 [3]
Feb. 28, 2019
Oct. 23, 2014
Subsequent Event [Line Items]                    
Accelerated share repurchases, authorized amount         $ 5,000,000,000         $ 11,000,000,000
Accelerated share repurchases, cash paid       $ (5,000,000,000)            
Shares repurchased     18 136   307 [1] 150 154    
Accelerated share repurchase, percentage of agreement         80.00%          
Amount of remaining shares authorized in stock purchase plan, value           $ 14,200,000,000        
Subsequent Event [Member]                    
Subsequent Event [Line Items]                    
Accelerated share repurchases, authorized amount   $ 6,800,000,000                
Accelerated share repurchases, cash paid $ 6,800,000,000                  
Shares repurchased 130                  
Accelerated share repurchase, percentage of agreement   80.00%                
Amount of remaining shares authorized in stock purchase plan, value                 $ 5,300,000,000  
[1] Represents shares purchased pursuant to the accelerated share repurchase agreement with Citibank entered into on March 12, 2018, as well as other share repurchases. See above for additional information.
[2] Represents shares purchased pursuant to the accelerated share repurchase agreement with Citibank entered into on February 2, 2017. See above for additional information.
[3] Represents shares purchased pursuant to the accelerated share repurchase agreement entered into on March 8, 2016. See above for additional information.