Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenue	$ 1,704	$ 1,609	$ 3,275	$ 3,176
Expenses:
Operating-related expenses	452	441	898	877
Selling and general expenses	387	444	755	819
Depreciation	21	19	41	40
Amortization of intangibles	31	33	63	57
Total expenses	891	937	1,757	1,793
Operating profit	813	672	1,518	1,383
Other (income) expense, net	(6)	(11)	97	(16)
Interest expense, net	37	26	73	61
Income before taxes on income	782	657	1,348	1,338
Provision for taxes on income	180	156	293	303
Net income	602	501	1,055	1,035
Less: net income attributable to noncontrolling interests	(47)	(40)	(90)	(84)
Net income attributable to S&P Global Inc.	$ 555	$ 461	$ 965	$ 951
Net income:
Basic (USD per share)	$ 2.25	$ 1.83	$ 3.92	$ 3.78
Diluted (USD per share)	$ 2.24	$ 1.82	$ 3.89	$ 3.75
Weighted-average number of common shares outstanding:
Basic (shares)	246.1	251.1	246.4	251.7
Diluted (shares)	247.4	253.3	247.9	253.8
Actual shares outstanding at period end (shares)			246.3	251.4