Income Taxes (Summary Of Temporary Differences That Give Rise To Deferred Income Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Inventory costing and valuation methods	$ 4,643	$ 4,689
Allowance for doubtful accounts receivable	2,202	1,836
Insurance claims payable	10,807	9,486
Promotions payable	797	456
Accrued legal reserves	39	2,458
Stock based compensation	5,853	5,218
Federal and state benefit of uncertain tax positions	1,632	1,253
Other, net	920	379
Total deferred income tax assets	26,893	25,775
Fixed assets	(48,329)	(31,464)
Total deferred income tax liabilities	(48,329)	(31,464)
Net deferred income tax asset (liability)	$ (21,436)	$ (5,689)