Balance Sheet Components (Schedule of Other Accrued Liabilities) (Details) - USD ($) $ in Thousands		Jun. 27, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Current operating lease liabilities		$ 8,894	$ 9,149
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]		ntgr:OperatingLeaseLiabilityCurrentMember	ntgr:OperatingLeaseLiabilityCurrentMember
Sales and marketing		$ 99,597	$ 83,561
Warranty obligations		7,180	9,240
Sales returns	[1]	57,897	66,972
Freight and duty		13,567	14,885
Other		35,768	34,568
Total		$ 222,903	$ 218,375

[1] Inventory expected to be received from future sales returns amounted to $28.0 million and $32.6 million as of June 27, 2021 and December 31, 2020, respectively. Provisions to write down expected returned inventory to net realizable value amounted to $16.5 million and $18.0 million as of June 27, 2021 and December 31, 2020, respectively.