Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 602	$ 501	$ 1,055	$ 1,035
Other comprehensive income:
Foreign currency translation adjustment	(17)	(75)	1	(52)
Income tax effect	2	15	4	(3)
Foreign currency translation adjustment, net of income tax effect	(15)	(60)	5	(55)
Pension and other postretirement benefit plans	0	(15)	114	(11)
Income tax effect	0	4	(28)	3
Pension and other postretirement benefit plans, net of income tax effect	0	(11)	86	(8)
Unrealized gain on investment and forward exchange contracts	(4)		0
Income tax effect	1		0
Unrealized gain on investment and forward exchange contracts, net of income tax effect	(3)		0
Unrealized gain on investment and forward exchange contracts		(5)		(4)
Income tax effect		1		1
Unrealized gain on investment and forward exchange contracts, net of income tax effect		(4)		(3)
Comprehensive income	584	426	1,146	969
Less: comprehensive income attributable to nonredeemable noncontrolling interests	(3)	(5)	(6)	(8)
Less: comprehensive income attributable to redeemable noncontrolling interests	(44)	(36)	(84)	(76)
Comprehensive income attributable to S&P Global Inc.	$ 537	$ 385	$ 1,056	$ 885