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, 2020	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income from continuing operations									$ 58,293	$ 25,791	$ 17,326
Net loss from discontinued operations									0	0	(35,655)
Net income (loss)	$ 30,948	$ 25,535	$ 5,983	$ (4,173)	$ (420)	$ 12,529	$ 839	$ 12,843	58,293	25,791	(18,329)
Less: Net loss attributable to non-controlling interest in discontinued operations									0	0	(9,167)
Net income (loss) attributable to NETGEAR, Inc.									$ 58,293	$ 25,791	$ (9,162)
Denominator:
Weighted average common shares - basic									29,897	30,936	31,626
Potentially dilutive common share equivalent									743	1,029	1,511
Weighted average common shares - dilutive									30,640	31,965	33,137
Basic net income (loss) per share
Net income from continuing operations									$ 1.95	$ 0.83	$ 0.55
Net loss from discontinued operations attributable to NETGEAR, Inc.									0	0	(0.84)
Net income (loss) attributable to NETGEAR, Inc.	$ 1.02	$ 0.85	$ 0.20	$ (0.14)	$ (0.01)	$ 0.41	$ 0.03	$ 0.41	1.95	0.83	(0.29)
Diluted net income (loss) per share
Net income from continuing operations									1.90	0.81	0.52
Net loss from discontinued operations attributable to NETGEAR, Inc.									0	0	(0.80)
Net income (loss) attributable to NETGEAR, Inc.	$ 0.99	$ 0.83	$ 0.20	$ (0.14)	$ (0.01)	$ 0.39	$ 0.03	$ 0.39	$ 1.90	$ 0.81	$ (0.28)
Anti-dilutive employee stock-based awards, excluded									832	1,066	815