Income Taxes (Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 27, 2015	Dec. 28, 2014
Income Tax Disclosure [Abstract]
Inventory	$ 3,663	$ 3,821
Accounts receivable	939	1,093
Capitalized research and development costs	25,252	23,938
Financing liability	7,036	7,276
Net operating loss and foreign tax credit carryforwards	91,100	88,442
Interest carryforward	5,338	4,661
Deferred revenue	1,745	1,455
Pension	13,349	17,967
Uncertain tax positions	7,030	11,628
Deferred compensation	2,677	3,278
Stock based compensation	7,963	8,861
Depreciation	1,038	1,623
Other	10,472	4,557
Valuation allowance	(150,154)	(148,838)
Deferred tax assets	27,448	29,762
Intangibles	11,232	10,831
Unremitted earnings	8,235	6,177
Deferred tax liabilities	19,467	17,008
Net deferred tax assets	$ 7,981	$ 12,754