Investments (Details 3) $ in Thousands	Dec. 30, 2017 USD ($)
Contractual Maturity of Investment Securities
Due in less than one year, Amortized Cost	$ 280
Due after one year through five years, Amortized Cost	4,223
Due after five years through ten years, Amortized Cost	2,602
Due after ten years, Amortized Cost	9,287
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	16,392
Due in less than one year, Fair Value	279
Due after one year through five years, Fair Value	4,157
Due after five years through ten years, Fair Value	2,536
Due after ten years, Fair Value	9,292
Total Fair Value - Available-for-sale Debt Securities	$ 16,264