Condensed Consolidating Financial Statements (Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Income Statements, Captions [Line Items]
Revenue	$ 1,453	$ 1,341
Expenses:
Operating-related expenses	411	453
Selling and general expenses	351	334
Depreciation	19	18
Amortization of intangibles	24	24
Total expenses	805	829
Operating profit	648	512
Interest expense (income), net	37	40
Non-operating intercompany transactions	0	0
Income before taxes on income	611	472
(Benefit) provision for taxes on income	181	149
Equity in net income of subsidiaries	0	0
Net income	430	323
Less: net income attributable to noncontrolling interests	(31)	(29)
Net income attributable to S&P Global Inc.	399	294
Comprehensive income	468	343
Eliminations
Condensed Income Statements, Captions [Line Items]
Revenue	(32)	(31)
Expenses:
Operating-related expenses	(32)	(31)
Selling and general expenses	0	0
Depreciation	0	0
Amortization of intangibles	0	0
Total expenses	(32)	(31)
Operating profit	0	0
Interest expense (income), net	0	0
Non-operating intercompany transactions	838	428
Income before taxes on income	(838)	(428)
(Benefit) provision for taxes on income	0	0
Equity in net income of subsidiaries	(1,224)	(862)
Net income	(2,062)	(1,290)
Less: net income attributable to noncontrolling interests	(31)	(29)
Net income attributable to S&P Global Inc.	(2,093)	(1,319)
Comprehensive income	(2,064)	(1,290)
S&P Global Inc.
Condensed Income Statements, Captions [Line Items]
Revenue	180	171
Expenses:
Operating-related expenses	31	22
Selling and general expenses	20	21
Depreciation	7	9
Amortization of intangibles	0	0
Total expenses	58	52
Operating profit	122	119
Interest expense (income), net	39	42
Non-operating intercompany transactions	82	74
Income before taxes on income	1	3
(Benefit) provision for taxes on income	(11)	0
Equity in net income of subsidiaries	1,224	791
Net income	1,236	794
Less: net income attributable to noncontrolling interests	0	0
Net income attributable to S&P Global Inc.	1,236	794
Comprehensive income	1,238	802
Standard & Poor's Financial Services LLC
Condensed Income Statements, Captions [Line Items]
Revenue	438	342
Expenses:
Operating-related expenses	119	139
Selling and general expenses	88	35
Depreciation	3	2
Amortization of intangibles	0	0
Total expenses	210	176
Operating profit	228	166
Interest expense (income), net	0	0
Non-operating intercompany transactions	(19)	(5)
Income before taxes on income	247	171
(Benefit) provision for taxes on income	99	57
Equity in net income of subsidiaries	0	71
Net income	148	185
Less: net income attributable to noncontrolling interests	0	0
Net income attributable to S&P Global Inc.	148	185
Comprehensive income	147	185
Non-Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenue	867	859
Expenses:
Operating-related expenses	293	323
Selling and general expenses	243	278
Depreciation	9	7
Amortization of intangibles	24	24
Total expenses	569	632
Operating profit	298	227
Interest expense (income), net	(2)	(2)
Non-operating intercompany transactions	(901)	(497)
Income before taxes on income	1,201	726
(Benefit) provision for taxes on income	93	92
Equity in net income of subsidiaries	0	0
Net income	1,108	634
Less: net income attributable to noncontrolling interests	0	0
Net income attributable to S&P Global Inc.	1,108	634
Comprehensive income	$ 1,147	$ 646