Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 2,534	$ 2,303	$ 2,121
Other comprehensive income:
Foreign currency translation adjustments	(24)	10	(96)
Income tax effect	22	8	(4)
Foreign currency translation adjustment, net of income tax effect	(2)	18	(100)
Pension and other postretirement benefit plans	(31)	141	(14)
Income tax effect	8	(39)	9
Pension and other postretirement benefit plans, net of income tax effect	(23)	102	(5)
Unrealized gain (loss) on forward exchange contracts	17	(2)	2
Income tax effect	(5)	0	0
Unrealized loss on investment and forward exchange contracts, net of income tax effect	12	(2)	2
Comprehensive income	2,521	2,421	2,018
Less: comprehensive income attributable to nonredeemable noncontrolling interests	(14)	(10)	(12)
Less: comprehensive income attributable to redeemable noncontrolling interests	(181)	(170)	(151)
Comprehensive income attributable to S&P Global Inc.	$ 2,326	$ 2,241	$ 1,855