Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets:
Allowance for bad debts	$ 194	$ 151
Deferred preservation costs and inventory reserves	392	699
Investment in equity securities	925	802
Property	2,644	2,380
Intangible assets	502
Accrued expenses	3,782	2,859
Loss carryforwards	17,539	11,842
Credit carryforwards	2,166	4,124
Stock compensation	2,319	1,636
Other	969	717
Less valuation allowance	(2,292)	(2,395)
Total deferred tax assets	29,140	22,815
Deferred tax liabilities:
Prepaid items	(314)	(348)
Intangible assets	(5,814)	(3,935)
Other	(348)	(20)
Total deferred tax liabilities	(6,476)	(4,303)
Total net deferred tax assets	$ 22,664	$ 18,512