Earnings Per Share - Schedule of Calculation for Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Amounts attributable to S&P Global Inc. common shareholders:
Net income	$ 608	$ 797	$ 2,815	$ 2,349
Basic weighted-average number of common shares outstanding (shares)	329,600,000	240,900,000	314,500,000	240,800,000
Effect of stock options and other dilutive securities (shares)	1,300,000	800,000	1,200,000	900,000
Diluted weighted-average number of common shares outstanding (shares)	330,900,000	241,700,000	315,700,000	241,700,000
Net income: Basic (USD per share)	$ 1.84	$ 3.31	$ 8.95	$ 9.76
Net income: Diluted (USD per share)	$ 1.84	$ 3.30	$ 8.91	$ 9.72
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)			700,000	500,000