Subsequent Events (Details) $ in Thousands			12 Months Ended
	Jan. 24, 2017 USD ($) shares	Jan. 20, 2017 USD ($) building	Nov. 30, 2016 USD ($)	Dec. 23, 2016 USD ($) a
Subsequent events
Stock repurchased			$ 3,354
Common stock repurchase program, remaining authorized amount			$ 1,646
LIBOR
Subsequent events
Variable interest rate (as a percent)			2.75%
Subsequent events
Subsequent events
Stock repurchased (in shares) | shares	19,173
Stock repurchased	$ 595
Common stock repurchase program, remaining authorized amount	$ 1,051
Number of buildings used as collateral | building		2
Term of debt		10 years
Number of acres to be sold | a				67
Area of Land | a				268
Sale price				$ 10,250
Subsequent events | Maximum
Subsequent events
New mortgage		$ 12,000
Subsequent events | LIBOR
Subsequent events
Variable interest rate (as a percent)		1.95%