Selected Quarterly Financial Data (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended
Dec. 30, 2014	Sep. 30, 2014	Jul. 01, 2014	Apr. 01, 2014	Dec. 31, 2013	Oct. 01, 2013	Jul. 02, 2013	Apr. 02, 2013	Dec. 30, 2014	Dec. 31, 2013	Jan. 01, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 108,546us-gaap_SalesRevenueNet	$ 106,216us-gaap_SalesRevenueNet	$ 99,459us-gaap_SalesRevenueNet	$ 89,519us-gaap_SalesRevenueNet	$ 91,468us-gaap_SalesRevenueNet	$ 88,936us-gaap_SalesRevenueNet	$ 89,239us-gaap_SalesRevenueNet	$ 81,280us-gaap_SalesRevenueNet	$ 403,741us-gaap_SalesRevenueNet	$ 350,924us-gaap_SalesRevenueNet	$ 300,410us-gaap_SalesRevenueNet
Operating income	5,474us-gaap_OperatingIncomeLoss	5,045us-gaap_OperatingIncomeLoss	5,941us-gaap_OperatingIncomeLoss	2,456us-gaap_OperatingIncomeLoss	5,163us-gaap_OperatingIncomeLoss	5,580us-gaap_OperatingIncomeLoss	937us-gaap_OperatingIncomeLoss	2,572us-gaap_OperatingIncomeLoss	18,915us-gaap_OperatingIncomeLoss	14,252us-gaap_OperatingIncomeLoss	16,052us-gaap_OperatingIncomeLoss
Net income	$ 3,535us-gaap_NetIncomeLoss	$ 2,943us-gaap_NetIncomeLoss	$ 3,527us-gaap_NetIncomeLoss	$ 1,424us-gaap_NetIncomeLoss	$ 2,407us-gaap_NetIncomeLoss	$ 3,265us-gaap_NetIncomeLoss	$ 68us-gaap_NetIncomeLoss	$ 924us-gaap_NetIncomeLoss	$ 11,428us-gaap_NetIncomeLoss	$ 6,665us-gaap_NetIncomeLoss	$ 5,163us-gaap_NetIncomeLoss
Basic EPS (USD per share)	$ 0.12us-gaap_EarningsPerShareBasic	$ 0.10us-gaap_EarningsPerShareBasic	$ 0.12us-gaap_EarningsPerShareBasic	$ 0.05us-gaap_EarningsPerShareBasic	$ 0.09us-gaap_EarningsPerShareBasic	$ 0.11us-gaap_EarningsPerShareBasic	$ 0.01us-gaap_EarningsPerShareBasic	$ 0.04us-gaap_EarningsPerShareBasic	$ 0.38us-gaap_EarningsPerShareBasic	$ 0.25us-gaap_EarningsPerShareBasic	$ 0.22us-gaap_EarningsPerShareBasic
Diluted EPS (USD per share)	$ 0.11us-gaap_EarningsPerShareDiluted	$ 0.10us-gaap_EarningsPerShareDiluted	$ 0.11us-gaap_EarningsPerShareDiluted	$ 0.05us-gaap_EarningsPerShareDiluted	$ 0.08us-gaap_EarningsPerShareDiluted	$ 0.11us-gaap_EarningsPerShareDiluted	$ 0.01us-gaap_EarningsPerShareDiluted	$ 0.04us-gaap_EarningsPerShareDiluted	$ 0.37us-gaap_EarningsPerShareDiluted	$ 0.24us-gaap_EarningsPerShareDiluted	$ 0.22us-gaap_EarningsPerShareDiluted

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References+ Details

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 20

-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Other Comprehensive Income

-URI http://asc.fasb.org/extlink&oid=6519514

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Net Income

-URI http://asc.fasb.org/extlink&oid=6518256

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.19)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.18)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.22)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e565-108580

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 19

-Article 5

+ Details