Acquisitions and Dispositions - Summary of Purchase Price Allocation Initially Recorded on Unaudited Consolidated Balance Sheet for all Acquisitions (Details) - USD ($) $ in Millions		Sep. 30, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill		$ 735	$ 734
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Goodwill		17
Intangible assets	[1]	12
Net tangible assets (liabilities)		1
Deferred tax liabilities, net		(2)
Total purchase price consideration	[2]	$ 28

[1] Identifiable definite-lived intangible assets acquired during 2015 were comprised of trade names of $2 million with a weighted average life of 9.9 years, customer lists and supplier relationships of $7 million with a weighted average life of 5.9 years and technology and other of $3 million with a weighted average life of 2.5 years. The overall weighted-average life of the identifiable definite-lived intangible assets acquired in the purchase of these businesses during 2015 was 6.0 years, and will be amortized on a straight-line basis over their estimated useful lives from acquisition date.

[2] Subject to adjustment based on (i) final working capital adjustment calculations to be determined for BestTables and Dimmi, and (ii) indemnification obligations for general representations and warranties of the acquired company stockholders.