Strategic Initiatives - Restructuring Liability (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	$ 56	$ 33
Restructuring costs accrued during the period	53	65
Restructuring costs paid during the period	(61)	(42)
Restructuring liability at end of period	48	56
Remaining restructuring liability	48	56	$ 15
Severance and Other Employee Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	10	10
Restructuring costs accrued during the period	23	12
Restructuring costs paid during the period	(17)	(12)
Restructuring liability at end of period	16	10
Remaining restructuring liability	16	10
Lease Termination and Associated Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	46	23
Restructuring costs accrued during the period	2	38
Restructuring costs paid during the period	(16)	(15)
Restructuring liability at end of period	32	46
Remaining restructuring liability	32	46
Other
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	0	0
Restructuring costs accrued during the period	28	15
Restructuring costs paid during the period	(28)	(15)
Restructuring liability at end of period	0	0
Remaining restructuring liability	$ 0	$ 0