Earnings Per Share - (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Amounts attributable to S&P Global Inc. common shareholders:
Net income	$ 742	$ 608	$ 2,047	$ 2,815
Basic weighted-average number of common shares outstanding (shares)	317,500,000	329,600,000	319,400,000	314,500,000
Effect of stock options and other dilutive securities (shares)	500,000	1,300,000	500,000	1,200,000
Diluted weighted-average number of common shares outstanding (shares)	318,000,000.0	330,900,000	319,900,000	315,700,000
Net income: Basic (USD per share)	$ 2.34	$ 1.84	$ 6.41	$ 8.95
Net income: Diluted (USD per share)	$ 2.33	$ 1.84	$ 6.40	$ 8.91
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	700,000