Stockholders' Equity - Restricted Stock Units and Awards (Details) - $ / shares	12 Months Ended
Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Restricted stock units and awards
Number of Shares, Restricted stock granted	286,294	227,905	62,225
Restricted Stock Units (RSUs)
Restricted stock units and awards
Outstanding, Number of Shares, Beginning Balance	147,589	277,390	269,259
Number of Shares, Restricted stock granted	285,005	225,392	59,780
Number of Shares, Restricted stock released	(30,789)	(209,193)	(46,759)
Number of Shares, Restricted stock forfeited	(66,000)	(146,000)	(4,890)
Outstanding, Number of Shares, Ending Balance	335,805	147,589	277,390
Outstanding, Weighted Average Grant Date Fair Value, Beginning Balance	$ 8.59	$ 5.52	$ 4.42
Weighted Average Grant Date Fair Value, Restricted stock granted	11.89	8.66	9.76
Weighted Average Grant Date Fair Value, Restricted stock released	8.30	4.82	4.29
Weighted Average Grant Date Fair Value, Restricted stock forfeited	9.67	8.28	8.18
Outstanding, Weighted Average Grant Date Fair Value, Ending Balance	$ 11.20	$ 8.59	$ 5.52
Restricted Stock Awards
Restricted stock units and awards
Outstanding, Number of Shares, Beginning Balance	2,513	2,445	3,503
Number of Shares, Restricted stock granted	1,289	2,513	2,445
Number of Shares, Restricted stock released	(2,513)	(2,445)	(3,503)
Outstanding, Number of Shares, Ending Balance	1,289	2,513	2,445
Outstanding, Weighted Average Grant Date Fair Value, Beginning Balance	$ 7.96	$ 8.18	$ 5.71
Weighted Average Grant Date Fair Value, Restricted stock granted	15.51	7.96	8.18
Weighted Average Grant Date Fair Value, Restricted stock released	7.96	7.96	5.71
Outstanding, Weighted Average Grant Date Fair Value, Ending Balance	$ 15.51	$ 7.96	$ 8.18

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- 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.

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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