Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 1,689	$ 1,546	$ 4,964	$ 4,721
Expenses:
Operating-related expenses	438	410	1,337	1,287
Selling and general expenses	360	379	1,115	1,197
Depreciation	20	20	61	60
Amortization of intangibles	29	33	92	91
Total expenses	847	842	2,605	2,635
Gain on dispositions	(49)	0	(49)	0
Operating profit	891	704	2,408	2,086
Other expense (income), net	8	(6)	104	(22)
Interest expense, net	32	38	105	98
Income before taxes on income	851	672	2,199	2,010
Provision for taxes on income	189	137	482	440
Net income	662	535	1,717	1,570
Less: net income attributable to noncontrolling interests	(45)	(40)	(135)	(123)
Net income attributable to S&P Global Inc.	$ 617	$ 495	$ 1,582	$ 1,447
Net income:
Basic (USD per share)	$ 2.52	$ 1.97	$ 6.43	$ 5.75
Diluted (USD per share)	$ 2.50	$ 1.95	$ 6.40	$ 5.70
Weighted-average number of common shares outstanding:
Basic (shares)	245.0	251.3	245.9	251.6
Diluted (shares)	246.5	253.5	247.4	253.7
Actual shares outstanding at period end (shares)	244.4	250.9	244.4	250.9