Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 2,303	$ 2,121	$ 1,638
Other comprehensive income:
Foreign currency translation adjustments	10	(96)	93
Income tax effect	8	(4)	0
Foreign currency translation adjustment, net of income tax effect	18	(100)	93
Pension and other postretirement benefit plans	141	(14)	52
Income tax effect	(39)	9	(11)
Pension and other postretirement benefit plans, net of income tax effect	102	(5)	41
Unrealized (loss) gain on investment and forward exchange contracts	(2)	2	(10)
Income tax effect	0	0	0
Unrealized loss on investment and forward exchange contracts, net of income tax effect	(2)	2	(10)
Comprehensive income	2,421	2,018	1,762
Less: comprehensive income attributable to nonredeemable noncontrolling interests	(10)	(12)	(13)
Less: comprehensive income attributable to redeemable noncontrolling interests	(170)	(151)	(129)
Comprehensive income attributable to S&P Global Inc.	$ 2,241	$ 1,855	$ 1,620