CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 2,303,806	$ 2,481,526
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	871,046	796,610
Provision for losses on doubtful receivables	73,076
Deferred income taxes	1,315,209
Stock-based compensation expense	80,094	56,411
Gains on sale of property, plant and equipment, net	(398,206)	(325,644)
Changes in operating assets and liabilities	(4,529,487)	(5,606,369)
Net cash used in operating activities	(284,462)	(2,597,466)
Cash flows from investing activities:
Additions to property, plant and equipment	(1,673,417)	(2,561,707)
Proceeds from sale of property, plant and equipment	1,229,753	664,146
Proceeds from sale of investments	1,289
Decrease in other assets		102,186
Net cash used in investing activities	(442,375)	(1,795,375)
Cash flows from financing activities:
Proceeds from revolving line of credit and other long-term debt	21,208,662	72,542,810
Repayments of revolving line of credit and other long-term debt	(20,512,686)	(68,208,356)
Payment of debt issuance costs	(41,575)
Proceeds from exercise of stock options	41,588	16,807
Net cash provided by financing activities	695,989	4,351,261
Change in cash and cash equivalents	(30,848)	(41,580)
Cash and cash equivalents, beginning of period	59,056	106,833
Cash and cash equivalents, end of period	$ 28,208	$ 65,253