Supplemental Guarantor Condensed Consolidating Financials - Schedule of Consolidating Statement of Cash Flows (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 29, 2012
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	$ 508.4	$ 493.8	$ 370.2
INVESTING ACTIVITIES
Acquisition of businesses, net of cash acquired	0	(6.3)	(3,762.4)
Payment of additional acquisition consideration	0	(16.8)	(9.8)
Proceeds from sale of business, net of cash transferred	10.1	85.1	0
Purchase of property and equipment	(44.3)	(49.0)	(33.1)
Increase in equipment under customer usage agreements	(35.9)	(41.1)	(45.6)
Acquisition of in-process research and development assets	0	0	(4.5)
Net sales (purchases) of insurance contracts	13.8	(4.0)	0
Purchases of mutual funds	(29.7)	0	0
Sales of mutual funds	22.4	0	0
Proceeds from sale of intellectual property	0	60.0	12.5
Purchase of cost-method equity investments	0	(3.7)	(0.3)
Sale of a cost-method equity investment	0	2.1	0
Investment in subsidiaries		0
Increase in other assets	(3.4)	(7.5)	(7.6)
Net cash (used in) provided by investing activities	(67.0)	18.8	(3,850.8)
Proceeds from long-term debt	0	0	3,476.3
FINANCING ACTIVITIES
Repayment of long-term debt	(595.0)	(265.0)	0
Payment of debt issuance costs	(2.4)	(9.4)	(81.4)
Payment of contingent consideration	0	(43.0)	(51.7)
Payment of deferred acquisition consideration	(5.0)	(1.6)	(44.2)
Net proceeds from issuance of common stock pursuant to employee stock plans	81.4	75.1	28.6
Excess tax benefit related to equity awards	5.7	7.4	6.2
Payment of minimum tax withholdings on net share settlements of equity awards	(9.8)	(12.3)	(5.7)
Intercompany dividend		0
Net cash (used in) provided by financing activities	(525.1)	(248.8)	3,328.1
Effect of exchange rate changes on cash and cash equivalents	(2.7)	(1.7)	0.6
Net (decrease) increase in cash and cash equivalents	(86.4)	262.1	(151.9)
Cash and cash equivalents, beginning of period	822.5	560.4	712.3
Cash and cash equivalents, end of period	736.1	822.5	560.4
Eliminations [Member]
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	0	0	0
INVESTING ACTIVITIES
Acquisition of businesses, net of cash acquired		0	0
Payment of additional acquisition consideration		0	0
Proceeds from sale of business, net of cash transferred	0	0
Purchase of property and equipment	0	0	0
Increase in equipment under customer usage agreements	0	0	0
Acquisition of in-process research and development assets			0
Net sales (purchases) of insurance contracts	0	0
Purchases of mutual funds	0
Sales of mutual funds	0
Proceeds from sale of intellectual property		0	0
Purchase of cost-method equity investments		0	0
Sale of a cost-method equity investment		0
Investment in subsidiaries		0
Increase in other assets	0	0	0
Net cash (used in) provided by investing activities	0	0	0
Proceeds from long-term debt			0
FINANCING ACTIVITIES
Repayment of long-term debt	0	0
Payment of debt issuance costs	0	0	0
Payment of contingent consideration		0	0
Payment of deferred acquisition consideration	0	0	0
Net proceeds from issuance of common stock pursuant to employee stock plans	0	0	0
Excess tax benefit related to equity awards	0	0	0
Payment of minimum tax withholdings on net share settlements of equity awards	0	0	0
Intercompany dividend		0
Net cash (used in) provided by financing activities	0	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Net (decrease) increase in cash and cash equivalents	0	0	0
Cash and cash equivalents, beginning of period	0	0	0
Cash and cash equivalents, end of period	0	0	0
Parent/Issuer [Member]
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	500.4	237.4	236.1
INVESTING ACTIVITIES
Acquisition of businesses, net of cash acquired		(6.1)	(3,972.0)
Payment of additional acquisition consideration		(16.8)	(8.9)
Proceeds from sale of business, net of cash transferred	0	0
Purchase of property and equipment	(13.8)	(15.5)	(13.2)
Increase in equipment under customer usage agreements	(0.5)	(0.4)	0
Acquisition of in-process research and development assets			(4.5)
Net sales (purchases) of insurance contracts	13.8	(4.0)
Purchases of mutual funds	(29.7)
Sales of mutual funds	22.4
Proceeds from sale of intellectual property		0	0
Purchase of cost-method equity investments		(3.5)	0
Sale of a cost-method equity investment		2.1
Investment in subsidiaries		0
Increase in other assets	(1.0)	(2.0)	(0.6)
Net cash (used in) provided by investing activities	(8.8)	(46.2)	(3,999.2)
Proceeds from long-term debt			3,476.3
FINANCING ACTIVITIES
Repayment of long-term debt	(595.0)	(265.0)
Payment of debt issuance costs	(2.4)	(9.4)	(81.4)
Payment of contingent consideration		(43.0)	(51.7)
Payment of deferred acquisition consideration	(5.0)	(1.6)	(44.2)
Net proceeds from issuance of common stock pursuant to employee stock plans	81.4	75.1	28.6
Excess tax benefit related to equity awards	5.7	7.4	6.2
Payment of minimum tax withholdings on net share settlements of equity awards	(9.8)	(12.3)	(5.7)
Intercompany dividend		169.2
Net cash (used in) provided by financing activities	(525.1)	(79.6)	3,328.1
Effect of exchange rate changes on cash and cash equivalents	0	0	0.3
Net (decrease) increase in cash and cash equivalents	(33.5)	111.6	(434.7)
Cash and cash equivalents, beginning of period	321.6	210.0	644.7
Cash and cash equivalents, end of period	288.1	321.6	210.0
Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	(52.7)	205.0	104.1
INVESTING ACTIVITIES
Acquisition of businesses, net of cash acquired		0	196.8
Payment of additional acquisition consideration		0	0
Proceeds from sale of business, net of cash transferred	0	83.6
Purchase of property and equipment	(22.5)	(23.4)	(12.4)
Increase in equipment under customer usage agreements	(20.9)	(24.4)	(30.7)
Acquisition of in-process research and development assets			0
Net sales (purchases) of insurance contracts	0	0
Purchases of mutual funds	0
Sales of mutual funds	0
Proceeds from sale of intellectual property		60.0	12.5
Purchase of cost-method equity investments		(0.2)	(0.3)
Sale of a cost-method equity investment		0
Investment in subsidiaries		1.8
Increase in other assets	(3.5)	(4.2)	(2.2)
Net cash (used in) provided by investing activities	(46.9)	93.2	163.7
Proceeds from long-term debt			0
FINANCING ACTIVITIES
Repayment of long-term debt	0	0
Payment of debt issuance costs	0	0	0
Payment of contingent consideration		0	0
Payment of deferred acquisition consideration	0	0	0
Net proceeds from issuance of common stock pursuant to employee stock plans	0	0	0
Excess tax benefit related to equity awards	0	0	0
Payment of minimum tax withholdings on net share settlements of equity awards	0	0	0
Intercompany dividend		(175.0)
Net cash (used in) provided by financing activities	0	(175.0)	0
Effect of exchange rate changes on cash and cash equivalents	0	(5.2)	1.6
Net (decrease) increase in cash and cash equivalents	(99.6)	118.0	269.4
Cash and cash equivalents, beginning of period	387.4	269.4	0
Cash and cash equivalents, end of period	287.8	387.4	269.4
Non-Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	60.7	51.4	30.0
INVESTING ACTIVITIES
Acquisition of businesses, net of cash acquired		(0.2)	12.8
Payment of additional acquisition consideration		0	(0.9)
Proceeds from sale of business, net of cash transferred	10.1	1.5
Purchase of property and equipment	(8.0)	(10.1)	(7.5)
Increase in equipment under customer usage agreements	(14.5)	(16.3)	(14.9)
Acquisition of in-process research and development assets			0
Net sales (purchases) of insurance contracts	0	0
Purchases of mutual funds	0
Sales of mutual funds	0
Proceeds from sale of intellectual property		0	0
Purchase of cost-method equity investments		0	0
Sale of a cost-method equity investment		0
Investment in subsidiaries		(1.8)
Increase in other assets	1.1	(1.3)	(4.8)
Net cash (used in) provided by investing activities	(11.3)	(28.2)	(15.3)
Proceeds from long-term debt			0
FINANCING ACTIVITIES
Repayment of long-term debt	0	0
Payment of debt issuance costs	0	0	0
Payment of contingent consideration		0	0
Payment of deferred acquisition consideration	0	0	0
Net proceeds from issuance of common stock pursuant to employee stock plans	0	0	0
Excess tax benefit related to equity awards	0	0	0
Payment of minimum tax withholdings on net share settlements of equity awards	0	0	0
Intercompany dividend		5.8
Net cash (used in) provided by financing activities	0	5.8	0
Effect of exchange rate changes on cash and cash equivalents	(2.7)	3.5	(1.3)
Net (decrease) increase in cash and cash equivalents	46.7	32.5	13.4
Cash and cash equivalents, beginning of period	113.5	81.0	67.6
Cash and cash equivalents, end of period	$ 160.2	$ 113.5	$ 81.0