Restructuring and Other Related Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 22	$ 28	$ 42	$ 72
Voluntary termination | Limited Voluntary Opportunity Plan (“LVOP”)
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			$ 17	18
Michael K. Tucker
Restructuring Cost and Reserve [Line Items]
Other nonrecurring expense				$ 2