Income Taxes (Details 2) (USD $)	12 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 30, 2012
Deferred Tax Asset:
State taxes	$ 2,635,000	$ 452,000
Reserves and contingent liabilities	8,860,000	5,883,000
Allowance for doubtful accounts	6,084,000	7,345,000
Accrued liabilities	12,212,000	14,425,000
Stock-based compensation	10,273,000	10,778,000
Loss carry-forwards	10,815,000	9,563,000
Valuation allowance on loss carry-forwards	(7,576,000)	(7,459,000)
Total deferred tax asset	43,303,000	40,987,000
Deferred Tax Liability:
Unbilled revenue	(49,150,000)	(47,281,000)
Prepaid expense	(5,834,000)	(7,522,000)
Intangibles	(29,257,000)	(24,933,000)
Property and equipment	(8,235,000)	(9,946,000)
Total deferred tax liability	(92,476,000)	(89,682,000)
Net deferred tax liability	(49,173,000)	(48,695,000)
Undistributed earnings of foreign subsidiaries	52,600,000
Unrecognized tax benefits that would affect the effective tax rate, if recognized	21,700,000
Period during which unrecognized tax benefits would affect the effective tax rate	12 months
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Beginning balance	25,886,000	24,092,000	25,940,000
Additions for current year tax positions	1,243,000	2,661,000	6,273,000
Additions for prior year tax positions	1,416,000	4,951,000	19,000
Reductions for prior year tax positions		(5,818,000)	(8,072,000)
Settlements	(6,828,000)		(68,000)
Ending balance	21,717,000	25,886,000	24,092,000
Amount of interest expense (net of interest income) accrued	900,000	2,300,000
Foreign
Deferred Tax Liability:
Net operating loss carry forwards which expire at various dates	36,800,000
Net operating loss carry forwards which have no expiration date	10,600,000
Expiration dates through 2034 | State
Deferred Tax Liability:
Net operating loss carry forwards which expire at various dates	22,800,000
Expiration dates through 2033 | Foreign
Deferred Tax Liability:
Net operating loss carry forwards which expire at various dates	$ 26,200,000