Segment and Related Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Segment	Sep. 30, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments (in segments) | Segment			4
Revenue	$ 1,324	$ 1,263	$ 3,938	$ 3,761
Operating Profit	410	366	1,493	1,261
S&P Ratings
Segment Reporting Information [Line Items]
Revenue	587	604	1,851	1,837
Operating Profit	194	183	846	730
Insurance recoveries	86		40
Legal settlement charge		60		60
S&P Capital IQ and SNL
Segment Reporting Information [Line Items]
Revenue	356	311	1,000	919
Operating Profit	53	64	178	172
S&P DJ Indices
Segment Reporting Information [Line Items]
Revenue	156	143	446	412
Operating Profit	106	86	297	260
C&C
Segment Reporting Information [Line Items]
Revenue	248	227	707	657
Operating Profit	93	71	265	217
Intersegment elimination
Segment Reporting Information [Line Items]
Revenue	(23)	(22)	(66)	(64)
Operating Profit	0	0	0	0
Total
Segment Reporting Information [Line Items]
Revenue	1,324	1,263	3,938	3,761
Operating Profit	446	404	1,586	1,379
Unallocated expense
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Operating Profit	$ (36)	$ (38)	(93)	$ (118)
Cash proceeds from sale of business			$ 11