Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions		Total	Total SPGI Equity	Common Stock $1 par	Additional Paid-in Capital	Retained Income	Accumulated Other Comprehensive Loss	Less: Treasury Stock	Noncontrolling Interests
Beginning Balance at Dec. 31, 2019		$ 536	$ 479	$ 294	$ 903	$ 12,205	$ (624)	$ (12,299)	$ 57
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	[1]	1,840	1,832			1,885	(53)		8
Dividends		(493)	(484)			(484)			(9)
Share repurchases		(1,164)	(1,164)					1,164
Employee stock plans		17	17		14			(3)
Change in redemption value of redeemable noncontrolling interest		(238)	(238)			(238)
Ending Balance at Sep. 30, 2020		498	442	294	917	13,368	(677)	(13,460)	56
Beginning Balance at Jun. 30, 2020		268	210	294	762	13,189	(704)	(13,331)	58
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	[1]	485	482			455	27		3
Dividends		(168)	(161)			(161)			(7)
Share repurchases		(11)	(11)		120			131
Employee stock plans		37	37		35			(2)
Change in redemption value of redeemable noncontrolling interest		(115)	(115)			(115)
Other		2							2
Ending Balance at Sep. 30, 2020		498	442	294	917	13,368	(677)	(13,460)	56
Beginning Balance at Dec. 31, 2020		571	509	294	946	13,367	(637)	(13,461)	62
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	[1]	2,253	2,236			2,349	(113)		17
Dividends		(567)	(557)			(557)			(10)
Employee stock plans		44	44		55			11
Change in redemption value of redeemable noncontrolling interest		(387)	(387)			(387)
Other		1							1
Ending Balance at Sep. 30, 2021		1,915	1,845	294	1,001	14,772	(750)	(13,472)	70
Beginning Balance at Jun. 30, 2021		1,331	1,265	294	963	14,237	(764)	(13,465)	66
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	[1]	817	811			797	14		6
Dividends		(189)	(186)			(186)			(3)
Employee stock plans		31	31		38			7
Change in redemption value of redeemable noncontrolling interest		(76)	(76)			(76)
Other		1							1
Ending Balance at Sep. 30, 2021		$ 1,915	$ 1,845	$ 294	$ 1,001	$ 14,772	$ (750)	$ (13,472)	$ 70

[1] Excludes comprehensive income of $58 million and $40 million for the three months ended September 30, 2021 and 2020, respectively, and $161 million and $136 million for the nine months ended September 30, 2021 and 2020, respectively, attributable to our redeemable noncontrolling interest.