Goodwill and Other Intangible Assets - Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Goodwill, Beginning balance	$ 1,387	$ 1,409
Acquisitions	1,602	42
Dispositions		(32)
Reclassifications	(75)
Other (primarily Fx)	(32)	(32)
Goodwill, Ending balance	2,882	1,387
S&P Ratings
Goodwill [Roll Forward]
Goodwill, Beginning balance	122	125
Acquisitions	0	4
Dispositions		0
Reclassifications	0
Other (primarily Fx)	(8)	(7)
Goodwill, Ending balance	114	122
S&P Capital IQ and SNL
Goodwill [Roll Forward]
Goodwill, Beginning balance	452	469
Acquisitions	1,563	0
Dispositions		0
Reclassifications	0
Other (primarily Fx)	(17)	(17)
Goodwill, Ending balance	1,998	452
S&P DJ Indices
Goodwill [Roll Forward]
Goodwill, Beginning balance	376	376
Acquisitions	0	0
Dispositions		0
Reclassifications	0
Other (primarily Fx)	0	0
Goodwill, Ending balance	376	376
C&C
Goodwill [Roll Forward]
Goodwill, Beginning balance	437	439
Acquisitions	39	38
Dispositions		(32)
Reclassifications	(75)
Other (primarily Fx)	(7)	(8)
Goodwill, Ending balance	$ 394	$ 437