For each balance sheet presented, the amount of accumulated amortization for capitalized computer software costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
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Additions made to capitalized computer software costs during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
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-Name Accounting Standards Codification
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-Section S99
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Summary of Significant Accounting Policies - Property, Equipment and Capitalized Software Costs - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jul. 01, 2016	Jun. 30, 2017	Jul. 01, 2016	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Capitalized computer software, additions	$ 200	$ 100	$ 800	$ 200
Capitalized software developed for internal use	23,160		23,160		$ 21,918
Depreciation and amortization expense			769	830
Capitalized software costs, accumulated amortization	500	200	500	200
Capitalized Software [Member]
Property Plant And Equipment [Line Items]
Capitalized software developed for internal use	1,900	800	1,900	800
Depreciation and amortization expense	$ 100	$ 100	$ 100	$ 100
Capitalized Software [Member] \| Minimum [Member]
Property Plant And Equipment [Line Items]
Property, equipment and capitalized software, useful life			2 years
Capitalized Software [Member] \| Maximum [Member]
Property Plant And Equipment [Line Items]
Property, equipment and capitalized software, useful life			5 years