Strategic Initiatives - Restructuring Liability (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	$ 36	$ 52	$ 56	$ 33
Restructuring costs accrued during the period	12	8	34	49
Restructuring costs paid during the period	(18)	(7)	(60)	(29)
Restructuring liability at end of period	30	53	30	53
Severance and Other Employee Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	2	6	10	10
Restructuring costs accrued during the period	4	3	8	8
Restructuring costs paid during the period	(2)	(2)	(14)	(11)
Restructuring liability at end of period	4	7	4	7
Lease Termination and Associated Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	34	46	46	23
Restructuring costs accrued during the period	3	2	3	32
Restructuring costs paid during the period	(11)	(2)	(23)	(9)
Restructuring liability at end of period	26	46	26	46
Other
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	0	0	0	0
Restructuring costs accrued during the period	5	3	23	9
Restructuring costs paid during the period	(5)	(3)	(23)	(9)
Restructuring liability at end of period	$ 0	$ 0	$ 0	$ 0