Net Income (Loss) Per Share (Schedule of Net Income (Loss) Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ 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
Numerator:
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									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
Less: Net loss attributable to non-controlling interest in discontinued operations									0	(9,167)	0
Net income (loss) attributable to NETGEAR, Inc.	$ (420)	$ 12,529	$ 839	$ 12,843	$ (19,471)	$ 9,949	$ (5,230)	$ 5,590	$ 25,791	$ (9,162)	$ 19,436
Denominator:
Weighted average common shares - basic									30,936	31,626	32,097
Potentially dilutive common share equivalent									1,029	1,511	0
Weighted average common shares - dilutive									31,965	33,137	32,097
Basic net income (loss) per share
Net income (loss) from continuing operations	$ (0.01)	$ 0.41	$ 0.03	$ 0.41	$ (0.02)	$ 0.51	$ 0.02	$ 0.03	$ 0.83	$ 0.55	$ (0.35)
Net income (loss) from discontinued operations attributable to NETGEAR, Inc.									0	(0.84)	0.96
Net income (loss) attributable to NETGEAR, Inc.	(0.01)	0.41	0.03	0.41	(0.62)	0.31	(0.17)	0.18	0.83	(0.29)	0.61
Diluted net income (loss) per share
Net income (loss) from continuing operations	(0.01)	0.39	0.03	0.39	(0.02)	0.49	0.02	0.03	0.81	0.52	(0.35)
Net income (loss) from discontinued operations attributable to NETGEAR, Inc.									0	(0.80)	0.96
Net income (loss) attributable to NETGEAR, Inc.	$ (0.01)	$ 0.39	$ 0.03	$ 0.39	$ (0.62)	$ 0.30	$ (0.16)	$ 0.17	$ 0.81	$ (0.28)	$ 0.61
Anti-dilutive employee stock-based awards, excluded									1,066	815	279