Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Revenue		$ 352	$ 363
Costs and expenses:
Cost of revenue	[1]	16	13
Selling and marketing	[2]	172	157
Technology and content	[2]	61	49
General and administrative	[2]	37	33
Depreciation		16	14
Amortization of intangible assets		8	7
Total costs and expenses:		310	273
Operating income		42	90
Other income (expense):
Interest expense		(4)	(2)
Interest income and other, net			(2)
Total other expense, net		(4)	(4)
Income before income taxes		38	86
Provision for income taxes		(11)	(23)
Net income		$ 27	$ 63
Earnings per share attributable to common stockholders (Note 11):
Basic		$ 0.19	$ 0.44
Diluted		$ 0.18	$ 0.43
Weighted average common shares outstanding (Note 11):
Basic		145,445	143,145
Diluted		146,903	145,872

[1] Excludes amortization as follows:

[2] Includes stock-based compensation expense as follows: