Goodwill, Reclassified

No definition available.

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Namespace Prefix:	ntgr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

+ Details

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- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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Balance Sheet Components (Schedule Of Goodwill By Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2017
Goodwill [Roll Forward]
Goodwill (period start)	$ 85,463
Goodwill impairment charges	0	$ 0	$ 0
Goodwill (period end)	85,463	85,463
Arlo [Member]
Goodwill [Roll Forward]
Goodwill, Reclassified				$ 21,149
Goodwill (period end)	21,149
Connected Home [Member]
Goodwill [Roll Forward]
Goodwill, Reclassified				28,035
Goodwill (period end)	28,035
SMB [Member]
Goodwill [Roll Forward]
Goodwill, Reclassified				36,279
Goodwill (period end)	36,279
New Segment, Total [Member]
Goodwill [Roll Forward]
Goodwill, Reclassified				85,463
Retail [Member]
Goodwill [Roll Forward]
Goodwill (period start)	49,184	45,442
Goodwill, Acquired during period		3,742
Goodwill, Reclassified				(49,184)
Goodwill (period end)		49,184	45,442
Commercial [Member]
Goodwill [Roll Forward]
Goodwill (period start)	36,279	36,279
Goodwill, Acquired during period		0
Goodwill, Reclassified				(36,279)
Goodwill (period end)		36,279	36,279
Service Provider [Member]
Goodwill [Roll Forward]
Goodwill (period start)	0	0
Goodwill, Acquired during period		0
Goodwill, Reclassified				0
Goodwill (period end)		0	0
Old Segment, Total [Member]
Goodwill [Roll Forward]
Goodwill (period start)	$ 85,463	81,721
Goodwill, Acquired during period		3,742
Goodwill, Reclassified				$ (85,463)
Goodwill (period end)		$ 85,463	$ 81,721