Consolidated Statements of Income shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares
Income Statement [Abstract]
Revenue	$ 7,442	$ 6,699	$ 6,258
Expenses:
Operating-related expenses	2,092	1,976	1,838
Selling and general expenses	1,543	1,342	1,424
Depreciation	83	82	84
Amortization of intangibles	123	122	122
Total expenses	3,841	3,522	3,468
Gain on dispositions	(16)	(49)	0
Operating profit	3,617	3,226	2,790
Other (income) expense, net	(31)	98	(25)
Interest expense, net	141	141	134
Loss on extinguishment of debt	279	57	0
Income before taxes on income	3,228	2,930	2,681
Provision for taxes on income	694	627	560
Net income	2,534	2,303	2,121
Less: net income attributable to noncontrolling interests	(195)	(180)	(163)
Net income attributable to S&P Global Inc.	$ 2,339	$ 2,123	$ 1,958
Net income:
Basic (USD per share) | $ / shares	$ 9.71	$ 8.65	$ 7.80
Diluted (USD per share) | $ / shares	$ 9.66	$ 8.60	$ 7.73
Weighted-average number of common shares outstanding:
Basic (shares) | shares	241.0	245.4	250.9
Diluted (shares) | shares	242.1	246.9	253.2
Actual shares outstanding at year end (shares) | shares	240.6	244.0	248.4