XML 160 R144.htm IDEA: XBRL DOCUMENT v3.20.4
Stock-Based Compensation - General Employees Stock Purchase Plan (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award Activity      
Weighted-average fair value $ 21.58 $ 34.19 $ 41.59
Allocated Share Based Compensation Expense $ 262 $ 278 $ 302
General Employees' Stock Purchase Plan (GESPP)      
Share-based Compensation Arrangement by Share-based Payment Award Activity      
Number of shares authorized 60    
Option price, percentage of market value at date of grant 85.00%    
Weighted-average fair value $ 23.47 $ 27.14 $ 31.91
Option price, discount from market value at date of grant 15.00%    
Allocated Share Based Compensation Expense $ 31 $ 30 $ 30