Business Segments and Geographic Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Sep. 30, 2012	Oct. 02, 2011	Jan. 01, 2012
Statement of Operations Data
Revenues	$ 11,775	$ 12,580	$ 35,271	$ 37,581
Operating income	4,764	4,994	14,238	15,123
Net income	2,708	2,688	7,940	6,848
Balance Sheet Data
Current assets	23,113		23,113
Non-current assets	35,821		35,821		39,110
Current liabilities	4,252		4,252		3,645
Non-current liabilities	36,084		36,084		45,237
Shareholders' equity	$ 18,598		$ 18,598		$ 11,296