Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 457	$ 412	$ 887	$ 735
Other comprehensive income:
Foreign currency translation adjustment	42	(54)	72	(40)
Income tax effect	0	(1)	0	(1)
Foreign currency translation adjustment, net of income tax effect	42	(55)	72	(41)
Pension and other postretirement benefit plans	0	12	4	16
Income tax effect	2	(3)	1	(4)
Pension and other post-retirement benefit plans, net of income tax effect	2	9	5	12
Unrealized (loss) gain on investment and forward exchange contracts	(10)	(1)	(3)	3
Income tax effect	2	0	0	(1)
Unrealized gain (loss) on forward exchange contracts, net of income tax effect	(8)	(1)	(3)	2
Comprehensive income	493	365	961	708
Less: comprehensive income attributable to nonredeemable noncontrolling interests	(5)	(2)	(6)	(5)
Less: comprehensive income attributable to redeemable noncontrolling interests	(31)	(27)	(61)	(53)
Comprehensive income attributable to S&P Global Inc.	$ 457	$ 336	$ 894	$ 650