Borrowings - Lease Agreement/Term Loan (Details)			12 Months Ended
	Dec. 30, 2015 USD ($)	Jul. 29, 2013 USD ($)	Dec. 31, 2015 USD ($) installment	Dec. 31, 2014 USD ($)	Aug. 10, 2012 USD ($)	Jun. 01, 2011 USD ($)
Remaining scheduled principal repayments
Term loan			$ 3,606,000	$ 2,653,000
Master Lease Agreement
Obligations under capital lease			$ 8,961,000	$ 15,128,000
H-P Loan
Term Loan
Term of Term Loan Agreement	5 years
Term debt	$ 3,600,000
Number of quarterly installments for payable of remaining loan principal | installment			20
Repayment of principal in quarterly installments			$ 195,000
Accrued interest (as a percent)			2.95%
Schedule of remaining principal payments
2016			$ 508,000
2017			695,000
2018			715,000
2019			737,000
2020			758,000
2021			193,000
Total			3,606,000
Remaining scheduled principal repayments
2016			508,000
2017			$ 695,000
Master Lease Agreement
Interest, fixed rate (as a percent)			2.95%
Equipment Loan Agreement
Term Loan
Term of Term Loan Agreement			4 years
Term debt						$ 25,500,000
Repayment of principal in quarterly installments			$ 530,600
Accrued interest (as a percent)			3.00%
Interest, base rate			one month LIBOR rate for dollar deposits
Master Lease Agreement
Interest, fixed rate (as a percent)			3.00%
Principal amount outstanding			$ 200,000
Master Lease Agreement
Term Loan
Accrued interest (as a percent)		3.39%
Master Lease Agreement
Master lease facility, amount			$ 5,000,000		$ 25,000,000
Obligations under capital lease		$ 21,200,000
Interest, fixed rate (as a percent)		3.39%
Term of capital lease		48 months	48 months
Ending purchase price of underlying assets		$ 1			$ 1
Amount outstanding under Credit Agreement			$ 8,700,000
The reductions to the remaining principal balance applying the interest method to the estimated minimum lease payments
2016			5,455,000
2017			3,269,000
Capital lease, amount			$ 8,724,000