Strategic Initiatives - Restructuring Liability (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	$ 33	$ 0
Restructuring costs accrued during the period	65	57
Restructuring costs paid during the period	(42)	(24)
Restructuring liability at end of period	56	33
Severance and Other Employee Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	10	0
Restructuring costs accrued during the period	12	28
Restructuring costs paid during the period	(12)	(18)
Restructuring liability at end of period	10	10
Lease Termination and Associated Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	23	0
Restructuring costs accrued during the period	38	29
Restructuring costs paid during the period	(15)	(6)
Restructuring liability at end of period	46	23
Other
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	0	0
Restructuring costs accrued during the period	15	0
Restructuring costs paid during the period	(15)	0
Restructuring liability at end of period	$ 0	$ 0