v3.8.0.1

Segment and Geographical Information - Revenue by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Segment Reporting Information [Line Items]
Total revenue	$ 44,216	$ 44,536	$ 41,972	$ 43,366	$ 43,513	$ 40,791	$ 38,184	$ 39,266	$ 174,090	$ 161,754	$ 138,681
Percentage of total revenue									100.00%	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Total revenue									$ 158,207	$ 147,830	$ 129,085
United States | Geographic Concentration | Revenue
Segment Reporting Information [Line Items]
Percentage of total revenue									91.00%	91.00%	93.00%
International
Segment Reporting Information [Line Items]
Total revenue									$ 15,883	$ 13,924	$ 9,596
International | Geographic Concentration | Revenue
Segment Reporting Information [Line Items]
Percentage of total revenue									9.00%	9.00%	7.00%

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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