Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 52,848	$ 25,692
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	38,864	33,285
Stock-based compensation	23,703	26,074
Excess tax benefits from stock-based awards	(139)	(453)
Other non-cash items, net	138	211
Changes in operating assets and liabilities, excluding the effects of acquisitions:
Accounts receivable	22,185	38,698
Accounts payable and accrued expenses	(6,111)	(6,233)
Accrued compensation and benefits	(18,631)	(7,635)
Deferred revenue	30,843	33,482
Accrued and deferred income taxes	(40,553)	(11,901)
Other current assets and prepaid expenses	(3,197)	3,573
Other noncurrent assets and liabilities	(3,518)	(1,759)
Net cash provided by operating activities	96,432	133,034
Cash flows from investing activities:
Additions to property and equipment	(12,426)	(16,624)
Acquisitions of businesses, net of cash acquired	(222,423)	(1,170)
Net cash used by investing activities	(234,849)	(17,794)
Cash flows from financing activities:
Borrowings under credit facility	0	40,000
Repayments of borrowings under credit facility	(61,875)	(80,000)
Repurchases of common stock	(34,947)	(14,983)
Proceeds from issuance of common stock	2,874	14,123
Excess tax benefits from stock-based awards	139	453
Payments of withholding taxes in connection with vesting of stock-based awards	(12,891)	(19,465)
Net cash used by financing activities	(106,700)	(59,872)
Effect of exchange rate changes on cash and cash equivalents	(3,617)	861
Net (decrease) increase in cash and cash equivalents	(248,734)	56,229
Cash and cash equivalents, beginning of period	489,543	167,878
Cash and cash equivalents, end of period	$ 240,809	$ 224,107