Annual report pursuant to Section 13 and 15(d)

Income Taxes - Reconciliation of the Change in Unrecognized Tax Benefits (Details)

v3.20.4
Income Taxes - Reconciliation of the Change in Unrecognized Tax Benefits (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]      
Balance, January 1 $ 1,175 $ 2,197 $ 1,773
Increases related to positions taken during the current year 238 238 395
Increases related to positions taken during prior years 99 401 406
Decreases related to positions taken during prior years (172) (1,102) (371)
Settlements 0 (541) (6)
Expiration of statute of limitations 0 (18) 0
Balance, December 31 $ 1,340 $ 1,175 $ 2,197