Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue	$ 2,087	$ 1,846	$ 6,209	$ 5,575
Expenses:
Operating-related expenses	543	517	1,603	1,528
Selling and general expenses	423	341	1,157	949
Depreciation	20	20	63	60
Amortization of intangibles	21	32	74	94
Total expenses	1,007	910	2,897	2,631
Gain on dispositions	(3)	(8)	(5)	(16)
Operating profit	1,083	944	3,317	2,960
Other income, net	(22)	(6)	(51)	(16)
Interest expense, net	31	35	94	109
Loss on extinguishment of debt	0	279	0	279
Income before taxes on income	1,074	636	3,274	2,588
Provision for taxes on income	213	138	747	559
Net income	861	498	2,527	2,029
Less: net income attributable to noncontrolling interests	$ (64)	(43)	(178)	(144)
Net income attributable to S&P Global Inc.		$ 455	$ 2,349	$ 1,885
Net income:
Basic (USD per share)	$ 3.31	$ 1.89	$ 9.76	$ 7.82
Diluted (USD per share)	$ 3.30	$ 1.88	$ 9.72	$ 7.78
Weighted-average number of common shares outstanding:
Basic (shares)	240.9	240.6	240.8	241.2
Diluted (shares)	241.7	241.6	241.7	242.3
Actual shares outstanding at period end (shares)	241.0	240.6	241.0	240.6