Consolidated Statements of Operations (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Income Statement [Abstract]
Revenue	$ 363		$ 281
Costs and expenses:
Cost of revenue	13	[1]	8	[1]
Selling and marketing	157	[2]	101	[2]
Technology and content	49	[2]	38	[2]
General and administrative	33	[2]	26	[2]
Depreciation	14		10
Amortization of intangible assets	7		2
Total costs and expenses:	273		185
Operating income	90		96
Other income (expense):
Interest expense	(2)		(2)
Interest income and other, net	(2)
Total other expense, net	(4)		(2)
Income before income taxes	86		94
Provision for income taxes	(23)		(26)
Net income	$ 63		$ 68
Earnings per share attributable to common stockholders (Note 13):
Basic	$ 0.44		$ 0.48
Diluted	$ 0.43		$ 0.47
Weighted average common shares outstanding (Note 13):
Basic	143,145		142,399
Diluted	145,872		145,665

[1] Excludes amortization as follows:

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