Discontinued Operations - Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations, net of income tax	$ 0	$ 14,609	$ (42,704)	$ 24,818
Separation costs	$ 200	400	500	800
GoTo Business Division [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenues		168,993	58,215	335,898
Cost of net revenues		37,131	15,456	76,412
Gross margin		131,862	42,759	259,486
Research and development		24,110	9,108	45,837
Sales, marketing and services		52,528	20,881	111,349
General and administrative		18,626	7,636	31,586
Amortization of other intangible assets		3,464	1,176	7,138
Restructuring		436	3,189	945
Separation		13,550	40,573	27,781
Total operating expenses		112,714	82,563	224,636
Income (loss) from discontinued operations before income taxes		19,148	(39,804)	34,850
Income tax expense		4,539	2,900	10,032
Income (loss) from discontinued operations, net of income tax		$ 14,609	$ (42,704)	$ 24,818