Income Taxes - Significant components of the Company’s deferred taxes (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Deferred income tax liabilities
Property, plant and equipment	$ 24,748,000	$ 23,974,000
Tax-deductible goodwill	5,206,000	2,884,000
Non-deductible intangibles	5,069,000	1,564,000
State deferred taxes	1,487,000	1,286,000
Other	392,000	423,000
Deferred tax liabilities, gross	36,902,000	30,131,000
Deferred income tax assets
Compensation	6,243,000	5,175,000
Inventory valuation	806,000	630,000
Allowance for uncollectible accounts	967,000	1,343,000
Non-deductible accruals	3,820,000	4,199,000
Other	78,000	80,000
Capital loss carryforwards	0	26,138,000
Net operating loss carryforwards	4,975,000	2,037,000
Deferred tax assets, gross	16,889,000	39,602,000
Deferred Tax Assets, Valuation Allowance	(6,060,000)	(28,175,000)
Deferred Tax Assets, Net of Valuation Allowance	10,829,000	11,427,000
Deferred Tax Liabilities, Net	$ 26,073,000	$ 18,704,000