Employee Benefit Plans (Details)	12 Months Ended				55 Months Ended
	Jan. 01, 2019 USD ($) $ / shares shares	Jan. 02, 2018 USD ($) $ / shares	Jan. 03, 2017 USD ($) $ / shares	Dec. 31, 2013 shares	Jan. 02, 2018 USD ($) shares
Multiemployer Plans [Line Items]
Required employee age	21 years
Percentage of participants contributions vested	100.00%
Contributions by employer	$ 0	$ 0	$ 0
Weighted-average fair value per share at date of grant | $ / shares	$ 5.11	$ 1.74	$ 2.85
Employee Stock Purchase Plan [Member]
Multiemployer Plans [Line Items]
Maximum employee salary percentage				15.00%
Offering date percentage				85.00%
Purchase date percentage				85.00%
Number of shares authorized | shares				750,000
Shares issued | shares	23,170				140,551
Reserved for future issuance | shares	609,449
Weighted-average fair value per share at date of grant | $ / shares	$ 1.57
Employee stock purchase plan, compensation expense	$ 36,000
Other long-term liabilities
Multiemployer Plans [Line Items]
Deferred compensation plan liability	1,000,000.0	$ 1,300,000			$ 1,300,000
Other Assets [Member]
Multiemployer Plans [Line Items]
Deferred compensation plan asset	$ 1,800,000	$ 1,900,000			$ 1,900,000
Measurement Input, Risk Free Interest Rate | Employee Stock Purchase Plan [Member]
Multiemployer Plans [Line Items]
Expected volatility rate	0.0211
Measurement Input, Expected Term | Employee Stock Purchase Plan [Member]
Multiemployer Plans [Line Items]
Expected volatility rate	0.25
Measurement Input, Price Volatility | Employee Stock Purchase Plan [Member]
Multiemployer Plans [Line Items]
Expected volatility rate	0.572
Measurement Input, Expected Dividend Rate | Employee Stock Purchase Plan [Member]
Multiemployer Plans [Line Items]
Expected volatility rate	0