Earnings Per Share - Schedule of Calculation for Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Amounts attributable to S&P Global Inc. common shareholders:
Net income	$ 795	$ 1,235
Basic weighted-average number of common shares outstanding (shares)	321,300,000	275,200,000
Effect of stock options and other dilutive securities (shares)	800,000	1,100,000
Diluted weighted-average number of common shares outstanding (shares)	322,100,000	276,300,000
Net income: Basic (USD per share)	$ 2.47	$ 4.49
Net income: Diluted (USD per share)	$ 2.47	$ 4.47
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted earnings (shares)	0	0
Restricted Stock and Unit Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted earnings (shares)	800,000	700,000