Earnings per Share - (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Amount attributable to S&P Global Inc. common shareholders:
Net income	$ 2,626	$ 3,248	$ 3,024
Basic weighted-average number of common shares outstanding (shares)	318,400,000	316,900,000	240,800,000
Effect of stock options and other dilutive securities (shares)	500,000	1,600,000	1,000,000.0
Diluted weighted-average number of common shares outstanding (shares)	318,900,000	318,500,000	241,800,000
Net income:
Basic (USD per share)	$ 8.25	$ 10.25	$ 12.56
Diluted (USD per share)	$ 8.23	$ 10.20	$ 12.51
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted EPS (shares)	0	0	0
Restricted performance shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted EPS (shares)	700,000	600,000	500,000