Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Abstract]
Carrying value of inventories	$ 2,786	$ 2,240
Accrued liabilities and allowances deductible for tax purposes on a cash basis	8,956	5,367
Goodwill	10,526	14,397
Stock-based compensation	8,251	7,398
Net operating loss carryforwards	39,670	49,561
Tax credit carryforwards	5,848	5,400
Other	7,564	9,850
Gross deferred tax assets	83,601	94,213
Less: valuation allowance	(41,858)	(42,524)
Net deferred tax assets	41,743	51,689
Plant and equipment, due to differences in depreciation	(3,887)	(4,586)
Other	(1,188)	(1,508)
Gross deferred tax liability	(5,075)	(6,094)
Net deferred tax assets	36,668	45,595
Current deferred tax assets	8,889	8,175
Non-current deferred tax assets	29,535	37,420
Non-current deferred tax liabilities	$ (1,756)