SCHEDULE II - Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Allowance for Uncollectible Accounts
Changes in valuation and qualifying accounts
Balance at Beginning of Year	$ 122,000	$ 86,000
Additions Charged to Costs and Expenses	62,000	42,000
Deductions	(27,000)	(6,000)
Balance at End of Year	157,000	122,000
Inventory Reserves
Changes in valuation and qualifying accounts
Balance at Beginning of Year	1,110,000	1,042,000
Additions Charged to Costs and Expenses	1,191,000	889,000
Deductions	(827,000)	(821,000)
Balance at End of Year	1,474,000	1,110,000
Self-insurance Accrual
Changes in valuation and qualifying accounts
Additions Charged to Costs and Expenses		49,000
Deductions		(84,000)
Balance at End of Year		$ 35,000