Goodwill and Acquired Intangible Assets (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Indefinite-lived Intangible Assets [Line Items]
Goodwill, impairment loss	$ 0	$ 0
Impairment of indefinite-lived intangible assets	0	$ 0
Finite-lived intangible assets, net	1,520,000,000		$ 1,567,000,000
Foreign currency translation adjustment
Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	$ (68,000,000)		$ (62,000,000)