CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012
Cash flows from operating activities:
Net income	$ 4,760,374	$ 11,449,408
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	2,657,081	2,363,367
Provision for losses on doubtful receivables	77,278	30,034
Deferred income taxes	230,462	(817,134)
Stock-based compensation expense	313,563	216,834
Gains on sale of property, plant and equipment, net	(352,893)	(362,098)
Changes in operating assets and liabilities	(5,382,460)	(4,935,149)
Net cash provided by operating activities	2,303,405	7,945,262
Cash flows from investing activities:
Additions to property, plant and equipment	(5,042,419)	(5,354,288)
Proceeds from sale of property, plant and equipment	1,251,959	4,213,153
Purchases of investments	(20,824)	(11,635)
Proceeds from sale of investments	41,646
Decrease in other assets		129,878
Net cash used in investing activities	(3,769,638)	(1,022,892)
Cash flows from financing activities:
Proceeds from revolving line of credit and other long-term debt	59,583,131	226,248,425
Repayments of revolving line of credit and other long-term debt	(57,933,289)	(229,906,247)
Payment of debt issuance costs	(358,975)
Proceeds from exercise of stock options	136,148	88,515
Net cash provided by (used in) financing activities	1,427,015	(3,569,307)
Change in cash and cash equivalents	(39,218)	3,353,063
Cash and cash equivalents, beginning of period	59,056	106,833
Cash and cash equivalents, end of period	$ 19,838	$ 3,459,896