Commitments And Contingencies (Narrative) (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2013 USD ($) $ / products	Dec. 31, 2017 USD ($) claims patent case	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) $ / products	Sep. 14, 2010 patents
Loss contingencies [Line Items]
Operating leases expiration date		Dec. 31, 2026
Operating Leases, Rent Expense		$ 10,100,000	$ 9,500,000	$ 9,800,000
Continued vesting period after termination without cause (in years)		1 year
Number of days for non-cancellation of purchase obligations prior to expected shipment date (in days)		30 days
Non-cancelable purchase commitments		$ 153,100,000
Liability for Director and Officer Indemnification Agreements		0
Liability For Customers, Distributors, and Resellers Indemnification Agreements		0
Liabilities for executive's employment agreements		$ 0
Number of exiting cases and proceedings that the Company currently believes are liking to have a material adverse effect on its financial position | claims		0
The future legnth the Company currently considered regarding existing cases and proceedings that are likely to have a material advese effect on it (in months)		12 months
Number of patents company is accused of infringing (in patents) | patents						8
Estimated future RAND royalty rate 2018 through 2020 | $ / products	5
Reasonable and nondiscriminatory (RAND) royalty rate (USD per unit) | $ / products	15
Ericsson v. NETGEAR [Member]
Loss contingencies [Line Items]
Foregone colleting verdict amount (in USD)					$ 3,600,000
Foregone reasonable and nondiscriminatory (RAND) royalty rate | $ / products					0.15
Chrismar Systems vs. NETGEAR [Member]
Loss contingencies [Line Items]
Number of patents company is accused of infringing (in patents) | patent		4
Number of active cases the suing company has | case		40
Realtime Data v. NETGEAR [Member]
Loss contingencies [Line Items]
Number of patents company is accused of infringing (in patents) | patent		4
Vivato v. NETGEAR [Member]
Loss contingencies [Line Items]
Number of patents company is accused of infringing (in patents) | patent		3
Hera Wireless v. NETGEAR [Member]
Loss contingencies [Line Items]
Number of patents company is accused of infringing (in patents) | patent		3
D-Link [Member] | Ericsson v. NETGEAR [Member]
Loss contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	$ 435,000
NETGEAR [Member] | Ericsson v. NETGEAR [Member]
Loss contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	3,555,000
Toshiba [Member] | Ericsson v. NETGEAR [Member]
Loss contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	2,445,000
Belkin [Member] | Ericsson v. NETGEAR [Member]
Loss contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	600,000
Acer Gateway [Member] | Ericsson v. NETGEAR [Member]
Loss contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	1,170,000
Dell [Member] | Ericsson v. NETGEAR [Member]
Loss contingencies [Line Items]
Loss Contingency, Damages Awarded, Value	$ 1,920,000
46 To 60 Days [Member]
Loss contingencies [Line Items]
Percentage of cancelable orders		50.00%
31 To 45 Days [Member]
Loss contingencies [Line Items]
Percentage of cancelable orders		25.00%
Chief Executive Officer [Member]
Loss contingencies [Line Items]
Number of weeks for which salary is payable upon termination of employment without cause (in days)		365 days
Number of years after change of control to trigger full accelerated vest of unvested portion of stock options (in years)		1 year
Senior Vice President Of Worldwide Operations And Support [Member]
Loss contingencies [Line Items]
Number of weeks for which salary is payable upon termination of employment without cause (in days)		273 days
Other Key Executives [Member]
Loss contingencies [Line Items]
Number of weeks for which salary is payable upon termination of employment without cause (in days)		182 days
Maximum number of years covered by accelerated vest for other key executives if term without cause is within one year of change in control (in years)		2 years
Minimum [Member] | 46 To 60 Days [Member]
Loss contingencies [Line Items]
Required notice period prior to the expected shipment date (in days)		46 days
Minimum [Member] | 31 To 45 Days [Member]
Loss contingencies [Line Items]
Required notice period prior to the expected shipment date (in days)		31 days
Maximum [Member] | 46 To 60 Days [Member]
Loss contingencies [Line Items]
Required notice period prior to the expected shipment date (in days)		60 days
Maximum [Member] | 31 To 45 Days [Member]
Loss contingencies [Line Items]
Required notice period prior to the expected shipment date (in days)		45 days
Earliest Tax Year [Member] | ITALY
Loss contingencies [Line Items]
Income Tax Examination, Year under Examination		2004
Latest Tax Year [Member] | ITALY
Loss contingencies [Line Items]
Income Tax Examination, Year under Examination		2012