Stockholders' Equity (Schedule of Reclassifications out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Net revenue	$ 252,971	$ 265,858	$ 230,852	$ 249,082	$ 288,928	$ 269,411	$ 255,276	$ 245,201	$ 998,763	$ 1,058,816	$ 1,039,169
Cost of revenue									704,535	717,118	731,453
Research and development									77,982	82,416	71,893
Sales and marketing									138,150	152,569	138,679
General and administrative									49,432	64,857	54,346
Income before income taxes									29,571	43,204	46,224
Tax impact from continuing operations	(1,045)	228	(756)	(2,207)	(19,210)	(5,483)	(1,271)	86	(3,780)	(25,878)	(57,357)
Net income (loss) from continuing operations	(420)	12,529	839	12,843	(535)	16,310	533	1,018	25,791	17,326	(11,133)
Net income (loss) from discontinued operations, net of tax									0	(35,655)	30,569
Net income (loss)	$ (420)	$ 12,529	$ 839	$ 12,843	$ (27,839)	$ 9,150	$ (5,230)	$ 5,590	25,791	(18,329)	19,436
Amount Reclassified from AOCI | Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Net revenue									1,929	665	(5,786)
Cost of revenue									(12)	(9)	18
Research and development									(57)	83	130
Sales and marketing									(284)	(102)	788
General and administrative									(41)	(53)	133
Income before income taxes									1,535	584	(4,717)
Tax impact from continuing operations									(322)	(123)	1,651
Net income (loss) from continuing operations									1,213	461	(3,066)
Net income (loss) from discontinued operations, net of tax									0	4	(1,890)
Net income (loss)									$ 1,213	$ 465	$ (4,956)