Acquisitions and Dispositions - Summary of Aggregate Purchase Price Consideration Allocated to Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 736		$ 732		$ 734
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Goodwill	17	[1]	17	[1]	253	[2]
Intangible assets	25	[3]	12	[4]	194	[5]
Net tangible assets (liabilities)	(8)	[6]	1		(7)	[7]
Deferred tax liabilities, net			(2)		(40)
Total purchase price consideration	$ 34	[8]	$ 28	[9]	$ 400

[1] Goodwill is not deductible for tax purposes.

[2] Goodwill in the amount of $5 million is expected to be deductible for tax purposes.

[3] Identifiable definite-lived intangible assets acquired during 2016 were comprised of trade names of $4 million with a weighted average life of 10 years, customer lists and supplier relationships of $4 million with a weighted average life of 6 years, subscriber relationships of $5 million with a weighted average life of approximately 7 years, and technology and other of $12 million with a weighted average life of approximately 5 years. The overall weighted-average life of the identifiable definite-lived intangible assets acquired in the purchase of these businesses during 2016 was 6 years, and will be amortized on a straight-line basis over their estimated useful lives from acquisition date.

[4] Identifiable definite-lived intangible assets acquired during 2015 were comprised of trade names of $2 million with a weighted average life of approximately 10 years, customer lists and supplier relationships of $7 million with a weighted average life of approximately 6 years and technology and other of $3 million with a weighted average life of approximately 2 years. The overall weighted-average life of the identifiable definite-lived intangible assets acquired in the purchase of these businesses during 2015 was 6 years, and will be amortized on a straight-line basis over their estimated useful lives from acquisition date.

[5] Identifiable definite-lived intangible assets acquired during 2014 were comprised of trade names of $44 million with a weighted average life of 10 years, customer lists and supplier relationships of $82 million with an approximate weighted average life of 7 years, subscriber relationships of $25 million with a weighted average life of 6 years and developed technology and other of $43 million with an approximate weighted average life of 5 years. The overall weighted-average life of the identifiable definite-lived intangible assets acquired in the purchase of the companies during 2014 was approximately 7 years, and will be amortized on a straight-line basis over their estimated useful lives from acquisition date.

[6] Primarily includes cash acquired of $4 million, accounts receivable of $2 million, and liabilities assumed, including accrued expenses and deferred merchant payables of $3 million and $10 million, respectively, which reflect their respective fair values at acquisition.

[7] Includes assets acquired, including cash of $62 million and accounts receivable of $25 million and liabilities assumed, including deferred merchant payables of $76 million, accrued expenses and other current liabilities of $15 million and deferred revenue of $5 million which reflect their respective fair values at acquisition date.

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

[9] Subject to adjustment based on indemnification obligations for general representations and warranties of certain acquired company stockholders.