Selected Quarterly Data (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 15, 2013	Jun. 16, 2012	Jun. 15, 2013	Jun. 16, 2012
Product Revenues	$ 28,906	$ 31,941	$ 55,464	$ 53,157
Service Revenues	34,644	30,330	68,093	59,623
Total revenues	63,550	62,271	123,557	112,780
Selling, general, and administrative expenses	7,049	6,237	13,640	11,994
Depreciation and amortization	2,163	1,911	4,022	3,683
Other expense (income) - net	(101)	2	(93)	2
Operating income (loss)	2,036	2,217	1,315	2,860
Income (loss) before income taxes	1,929	2,071	1,102	2,527
Provision for income taxes	872	853	465	1,039
Net Income (Loss) Attributable to Parent			591	1,488
Basic	18,138	16,689	18,125	15,588
Diluted	18,456	17,140	18,449	16,050
Unallocated Amount to Segment [Member]
Selling, general, and administrative expenses	7,049	6,237	13,640	11,994
Other expense (income) - net	$ 101	$ 2