Summary Of Significant Accounting Policies (Out of Period Adjustments) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 27, 2015	Mar. 29, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014	Dec. 28, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Decrease in revenue	$ (145,930)		$ (160,595)	$ (422,022)	$ (478,926)
Decrease in gross profit	(58,726)		(70,965)	(176,760)	(205,758)
Decrease in operating expenses	(60,798)		(60,201)	(183,654)	(179,841)
Net (loss) earnings	(3,991)		(4,075)	(16,042)	5,650	$ 10,953
Reduction of income taxes	$ (1,979)		(14,110)	$ (7,251)	$ (17,107)
Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Decrease in operating expenses			1,100
Net (loss) earnings		$ 1,000
Reduction of income taxes		$ 1,000
Correction Of Accounting For Maintenance Agreement [Member] | Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Decrease in revenue			700
Revenue Cutoff [Member] | Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Decrease in revenue			1,100
Decrease in gross profit			$ 600