Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 662	$ 535	$ 1,717	$ 1,570
Other comprehensive income:
Foreign currency translation adjustment	(35)	(1)	(33)	(53)
Income tax effect	2	2	6	(1)
Foreign currency translation adjustment, net of income tax effect	(33)	1	(27)	(54)
Pension and other postretirement benefit plans	2	5	116	(6)
Income tax effect	0	(1)	(28)	2
Pension and other postretirement benefit plans, net of income tax effect	2	4	88	(4)
Unrealized gain on investment and forward exchange contracts	(4)		(4)
Income tax effect	1		1
Unrealized gain on investment and forward exchange contracts, net of income tax effect	(3)		(3)
Unrealized gain on investment and forward exchange contracts		(4)		(8)
Income tax effect		1		2
Unrealized gain on investment and forward exchange contracts, net of income tax effect		(3)		(6)
Comprehensive income	628	537	1,775	1,506
Less: comprehensive income attributable to nonredeemable noncontrolling interests	(1)	(4)	(7)	(11)
Less: comprehensive income attributable to redeemable noncontrolling interests	(44)	(36)	(128)	(112)
Comprehensive income attributable to S&P Global Inc.	$ 583	$ 497	$ 1,640	$ 1,383