Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 808	$ 689
Other comprehensive income:
Foreign currency translation adjustments	(25)	(37)
Income tax effect	(5)	6
Foreign currency translation adjustment, net of income tax effect	(30)	(31)
Pension and other postretirement benefit plans	21	3
Income tax effect	(4)	(1)
Pension and other postretirement benefit plans, net of income tax effect	17	2
Unrealized gain (loss) on cash flow hedges	2	(9)
Income tax effect	0	2
Unrealized gain on investment and forward exchange contracts, net of income tax effect	2	(7)
Comprehensive income	797	653
Less: comprehensive income attributable to nonredeemable noncontrolling interests	(2)	(1)
Less: comprehensive income attributable to redeemable noncontrolling interests	(51)	(49)
Comprehensive income attributable to S&P Global Inc.	$ 744	$ 603