Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Revenue		$ 391	$ 405	$ 743	$ 768
Costs and expenses:
Cost of revenue	[1]	20	16	36	29
Selling and marketing	[2]	202	192	374	350
Technology and content	[2]	62	50	123	99
General and administrative	[2]	34	44	72	77
Depreciation		17	15	33	28
Amortization of intangible assets		8	9	15	16
Total costs and expenses:		343	326	653	599
Operating income		48	79	90	169
Other income (expense):
Interest expense		(3)	(2)	(6)	(4)
Interest income and other, net			5		3
Total other income (expense), net		(3)	3	(6)	(1)
Income before income taxes		45	82	84	168
Provision for income taxes		(11)	(24)	(22)	(47)
Net income		$ 34	$ 58	$ 62	$ 121
Earnings per share attributable to common stockholders (Note 4):
Basic		$ 0.23	$ 0.40	$ 0.42	$ 0.85
Diluted		$ 0.23	$ 0.40	$ 0.42	$ 0.83
Weighted average common shares outstanding (Note 4):
Basic		145,732	143,709	145,588	143,427
Diluted		147,060	145,959	146,982	145,916

[1] Excludes amortization as follows:

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