Earnings Per Share - (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Amounts attributable to S&P Global Inc. common shareholders:
Net income	$ 511	$ 972	$ 1,305	$ 2,207
Basic weighted-average number of common shares outstanding (shares)	319,300,000	338,000,000.0	320,300,000	306,800,000
Effect of stock options and other dilutive securities (shares)	500,000	1,300,000	600,000	1,200,000
Diluted weighted-average number of common shares outstanding (shares)	319,800,000	339,300,000	320,900,000	308,000,000.0
Net income: Basic (USD per share)	$ 1.60	$ 2.87	$ 4.08	$ 7.19
Net income: Diluted (USD per share)	$ 1.60	$ 2.86	$ 4.07	$ 7.17
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted earnings (shares)	0	0	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	600,000