Goodwill and Acquired Intangible Assets (Schedule of Changes in Goodwill) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Goodwill [Roll Forward]
Balance at beginning of period	$ 6,850
Goodwill acquired	1,888
Divestiture of business	(60)
Other adjustments	(245)
Balance at end of period	8,433
Market Technology
Goodwill [Roll Forward]
Balance at beginning of period	309
Goodwill acquired	1,873
Other adjustments	(11)
Balance at end of period	2,171
Investment Intelligence
Goodwill [Roll Forward]
Balance at beginning of period	2,541
Divestiture of business	(23)
Other adjustments	(90)
Balance at end of period	2,428
Corporate Platforms
Goodwill [Roll Forward]
Balance at beginning of period	481
Other adjustments	(12)
Balance at end of period	469
Market Services
Goodwill [Roll Forward]
Balance at beginning of period	3,519
Goodwill acquired	15
Divestiture of business	(37)
Other adjustments	(132)
Balance at end of period	$ 3,365