Consolidated Statement of (Deficit) Equity - USD ($) $ in Millions		Total		Total SPGI (Deficit) Equity		Common Stock $1 par	Additional Paid-in Capital	Retained Income	Accumulated Other Comprehensive Loss	Less: Treasury Stock	Noncontrolling Interests
Balance at beginning of period at Dec. 31, 2018		$ 684		$ 628		$ 294	$ 833	$ 11,284	$ (742)	$ (11,041)	$ 56
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income		522	[1]	519	[1]			410	109		3
Dividends		(141)		(141)				(141)
Share repurchases		(644)		(644)						644
Employee stock plans		(14)		(14)			(61)			(47)
Capital contribution from noncontrolling interest		(36)		(36)				(36)
Change in redemption value of redeemable noncontrolling interest		15		15				15
Other		2									2
Balance at end of period at Mar. 31, 2019		388		327		294	772	11,532	(633)	(11,638)	61
Balance at beginning of period at Dec. 31, 2019		536		479		294	903	12,205	(624)	(12,299)	57
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	[1]	604		603				639	(36)		1
Dividends		(161)		(161)				(161)
Share repurchases		(1,153)		(1,153)			(120)			1,033
Employee stock plans		(26)		(26)			(29)			(3)
Change in redemption value of redeemable noncontrolling interest		11		11				11
Other		(5)		(3)				(3)			(2)
Balance at end of period at Mar. 31, 2020		$ (194)		$ (250)		$ 294	$ 754	$ 12,691	$ (660)	$ (13,329)	$ 56

[1] Excludes comprehensive income of $49 million and $40 million for the three months ended March 31, 2020 and 2019, respectively, attributable to our redeemable noncontrolling interest.