Segment Information - Information on Reportable Segments for Reconciliation to Consolidated Net Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues
Total revenues	$ 141,569	$ 117,181	$ 357,752	$ 282,519
Operating income:
Total operating income	17,774	20,377	62,390	57,636
Other loss, net	(3,724)	(6,304)	(7,793)	(7,309)
Income tax expense	(5,313)	(5,667)	(19,873)	(18,313)
Net income	8,737	8,406	34,724	32,014
Operating Segments | Search and Content
Revenues
Total revenues	79,818	94,497	186,583	195,098
Operating income:
Total operating income	14,032	17,912	33,262	36,182
Operating Segments | Tax Preparation
Revenues
Total revenues	26,452	22,684	98,731	87,421
Operating income:
Total operating income	17,211	14,438	54,613	45,222
Operating Segments | E-Commerce
Revenues
Total revenues	35,299	0	72,438	0
Operating income:
Total operating income	2,378	0	5,856	0
Operating Segments | Corporate-level activity [Member]
Operating income:
Total operating income	$ (15,847)	$ (11,973)	$ (31,341)	$ (23,768)