Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenue (Note 3)	[1]	$ 422	$ 433	$ 798	$ 811
Costs and expenses:
Cost of revenue	[2]	27	24	48	44
Selling and marketing	[3]	180	217	357	416
Technology and content	[3]	74	68	148	135
General and administrative	[3]	45	46	88	88
Depreciation		23	21	46	41
Amortization of intangible assets		7	8	15	16
Total costs and expenses:		356	384	702	740
Operating income		66	49	96	71
Other income (expense):
Interest expense		(2)	(3)	(3)	(6)
Interest income and other, net		4	(4)	8	(2)
Total other income (expense), net		2	(7)	5	(8)
Income before income taxes		68	42	101	63
Provision for income taxes		(34)	(10)	(41)	(27)
Net income		$ 34	$ 32	$ 60	$ 36
Earnings per share attributable to common stockholders (Note 4):
Basic		$ 0.24	$ 0.23	$ 0.43	$ 0.26
Diluted		$ 0.24	$ 0.23	$ 0.43	$ 0.26
Weighted average common shares outstanding (Note 4):
Basic		139,070	137,831	138,744	138,572
Diluted		140,805	139,619	141,037	139,971

[1] Our revenue is recognized primarily at a point in time for all reported segments.

[2] Excludes amortization as follows:

[3] Includes stock-based compensation expense as follows