XML 159 R121.htm IDEA: XBRL DOCUMENT v3.20.4
Income Taxes - Unrecognized Tax Benefits (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2020
Unrecognized Tax Benefits        
Unrecognized tax benefits $ 28 $ 34 $ 34 $ 30
Unrecognized tax benefit, if recognized, would have an impact on effective tax rate       $ 30
Activity for unrecognized tax benefits [Roll Forward]        
Balance at beginning of period 28 34 22  
Tax positions related to current year additions 1 1 11  
Additions for tax positions of prior years 2 0 2  
Reductions due to lapse of statute of limitations on tax positions (1) (7) (1)  
Balance at end of period $ 30 $ 28 $ 34