Acquisitions and Divestitures - Purchase Price Allocation (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Sep. 01, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 2,949	$ 2,882		$ 1,387
SNL Financial LC
Business Acquisition [Line Items]
Current assets			$ 29
Property, plant and equipment			19
Goodwill			1,574
Other intangible assets, net			772
Other non-current assets			1
Total assets acquired			2,395
Current liabilities			(43)
Unearned revenue			(117)
Other non-current liabilities			(1)
Total liabilities acquired			(161)
Net assets acquired			2,234
SNL Financial LC | Databases and software
Business Acquisition [Line Items]
Other intangible assets, net			421
SNL Financial LC | Customer relationships
Business Acquisition [Line Items]
Other intangible assets, net			162
SNL Financial LC | Tradenames
Business Acquisition [Line Items]
Other intangible assets, net			185
SNL Financial LC | Other intangibles
Business Acquisition [Line Items]
Other intangible assets, net			$ 4