Per Share Amounts and Common Shares Outstanding Stock subscription (Details)	6 Months Ended
	Jul. 01, 2017 USD ($) $ / shares shares
Equity [Abstract]
Stock subscription offering, subscription price | $ / shares	$ 9.85	[1]
Stock subscription offering, number of shares subscribed | shares	1,275,428	[1]
stock subscription offering, value of shares subscribed | $	$ 12,563,000
Stock subscription offering, minimum financed amount | $	$ 5,000
Stock subscription offering, down payment	10.00%
Stock subscription offering, term (in years)	7 years
Stock subscription offering, interest rate	2.00%
Stock subscription offering, minimum amount to receive right | $	$ 5,000
Stock subscription offering, number of shares purchased to receive one right | shares	3
Stock subscription offering, number of rights issued | shares	423,600	[1]
Stock subscription offering, portion exercisable per year	14.29%
Stock subscription offering, right expiration term (in years)	7 years

[1] Adjusted for two-for-one stock split