Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Cash flows from operating activities:
Net loss	$ (9,141)	$ (23,892)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	21,454	20,613
Stock-based compensation	17,988	23,189
Excess tax benefits from stock-based awards	(102)	(56)
Non-cash portion of restructuring charges	260	0
Other non-cash items, net	330	45
Changes in operating assets and liabilities, excluding the effects of acquisitions:
Accounts receivable	21,184	35,219
Accounts payable, accrued expenses and other current liabilities	232	(1,679)
Accrued compensation and benefits	(53,840)	12,054
Deferred revenue	(11,726)	1,262
Accrued and deferred income taxes	(6,096)	(3,355)
Other current assets and prepaid expenses	(15,229)	1,441
Other noncurrent assets and liabilities	(13,292)	(3,587)
Net cash provided by (used in) operating activities	(47,978)	61,254
Cash flows from investing activities:
Additions to property and equipment	(7,100)	(4,185)
Acquisitions of businesses, net of cash acquired	0	(64,780)
Proceeds from sales of investments	1,502	0
Net cash used by investing activities	(5,598)	(68,965)
Cash flows from financing activities:
Borrowings	60,000	50,000
Repayments of borrowings under credit facility	(80,000)	0
Proceeds from issuance of common stock	0	1
Excess tax benefits from stock-based awards	102	56
Credit facility origination costs	0	(1,050)
Contingent consideration	(2,711)	(1,250)
Payments of withholding taxes in connection with vesting of stock-based awards	(18,623)	(14,833)
Net cash provided (used) by financing activities	(41,232)	32,924
Effect of exchange rate changes on cash and cash equivalents	(9,760)	(1,833)
Net increase (decrease) in cash and cash equivalents	(104,568)	23,380
Cash and cash equivalents, beginning of period	277,935	273,417
Cash and cash equivalents, end of period	$ 173,367	$ 296,797