Supplemental Guarantor Condensed Consolidating Financials - Schedule of Consolidating Statement of Cash Flows (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Mar. 28, 2015	Mar. 29, 2014
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	$ 311.3	$ 218.3
INVESTING ACTIVITIES
Net proceeds from sale of business	0	2.4
Purchase of property and equipment	(20.0)	(19.8)
Increase in equipment under customer usage agreements	(19.7)	(18.0)
Net sales of insurance contracts	(6.4)	13.8
Purchases of mutual funds	0	29.7
Sales of mutual funds	7.7	18.6
(Increase) decrease in other assets	(0.6)	(1.9)
Net cash used in investing activities	(39.0)	(34.6)
FINANCING ACTIVITIES
Repayment of long-term debt	(357.5)	(562.5)
Payments of Debt Issuance Costs	0	2.4
Payment Of Deferred Acquisition Consideration	0	5.0
Interest Rate Cap Agreements Aggregate Premium Payable	(6.1)	0
Net proceeds from issuance of common stock pursuant to employee stock plans	37.4	53.7
Excess tax benefit related to equity awards	6.0	4.1
Payment of minimum tax withholdings on net share settlements of equity awards	(12.1)	(9.1)
Net cash used in financing activities	(332.3)	(521.2)
Effect of exchange rate changes on cash and cash equivalents	(5.6)	(0.5)
Net decrease in cash and cash equivalents	(65.6)	(338.0)
Cash and cash equivalents, beginning of period	736.1	822.5
Cash and cash equivalents, end of period	670.5	484.5
Eliminations
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	0	0
INVESTING ACTIVITIES
Net proceeds from sale of business		0
Purchase of property and equipment	0	0
Increase in equipment under customer usage agreements	0	0
Net sales of insurance contracts	0	0
Purchases of mutual funds		0
Sales of mutual funds	0	0
(Increase) decrease in other assets	0	0
Net cash used in investing activities	0	0
FINANCING ACTIVITIES
Repayment of long-term debt	0	0
Payments of Debt Issuance Costs		0
Payment Of Deferred Acquisition Consideration		0
Interest Rate Cap Agreements Aggregate Premium Payable	0
Net proceeds from issuance of common stock pursuant to employee stock plans	0	0
Excess tax benefit related to equity awards	0	0
Payment of minimum tax withholdings on net share settlements of equity awards	0	0
Net cash used in financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net decrease in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	0	0
Parent/Issuer
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	420.0	343.4
INVESTING ACTIVITIES
Net proceeds from sale of business		0
Purchase of property and equipment	(5.4)	(5.7)
Increase in equipment under customer usage agreements	0	(0.5)
Net sales of insurance contracts	(6.4)	13.8
Purchases of mutual funds		29.7
Sales of mutual funds	7.7	18.6
(Increase) decrease in other assets	(0.8)	(0.9)
Net cash used in investing activities	(4.9)	(4.4)
FINANCING ACTIVITIES
Repayment of long-term debt	(357.5)	(562.5)
Payments of Debt Issuance Costs		2.4
Payment Of Deferred Acquisition Consideration		5.0
Interest Rate Cap Agreements Aggregate Premium Payable	(6.1)
Net proceeds from issuance of common stock pursuant to employee stock plans	37.4	53.7
Excess tax benefit related to equity awards	6.0	4.1
Payment of minimum tax withholdings on net share settlements of equity awards	(12.1)	(9.1)
Net cash used in financing activities	(332.3)	(521.2)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net decrease in cash and cash equivalents	82.8	(182.2)
Cash and cash equivalents, beginning of period	288.1	321.5
Cash and cash equivalents, end of period	370.9	139.3
Guarantor Subsidiaries
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	(116.7)	(122.5)
INVESTING ACTIVITIES
Net proceeds from sale of business		0
Purchase of property and equipment	(9.5)	(9.6)
Increase in equipment under customer usage agreements	(12.8)	(10.6)
Net sales of insurance contracts	0	0
Purchases of mutual funds		0
Sales of mutual funds	0	0
(Increase) decrease in other assets	(0.1)	(2.0)
Net cash used in investing activities	(22.4)	(22.2)
FINANCING ACTIVITIES
Repayment of long-term debt	0	0
Payments of Debt Issuance Costs		0
Payment Of Deferred Acquisition Consideration		0
Interest Rate Cap Agreements Aggregate Premium Payable	0
Net proceeds from issuance of common stock pursuant to employee stock plans	0	0
Excess tax benefit related to equity awards	0	0
Payment of minimum tax withholdings on net share settlements of equity awards	0	0
Net cash used in financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	(0.5)	0.1
Net decrease in cash and cash equivalents	(139.6)	(144.6)
Cash and cash equivalents, beginning of period	287.8	387.5
Cash and cash equivalents, end of period	148.2	242.9
Non-Guarantor Subsidiaries
OPERATING ACTIVITIES
Net cash provided by (used in) operating activities	8.0	(2.6)
INVESTING ACTIVITIES
Net proceeds from sale of business		2.4
Purchase of property and equipment	(5.1)	(4.5)
Increase in equipment under customer usage agreements	(6.9)	(6.9)
Net sales of insurance contracts	0	0
Purchases of mutual funds		0
Sales of mutual funds	0	0
(Increase) decrease in other assets	0.3	1.0
Net cash used in investing activities	(11.7)	(8.0)
FINANCING ACTIVITIES
Repayment of long-term debt	0	0
Payments of Debt Issuance Costs		0
Payment Of Deferred Acquisition Consideration		0
Interest Rate Cap Agreements Aggregate Premium Payable	0
Net proceeds from issuance of common stock pursuant to employee stock plans	0	0
Excess tax benefit related to equity awards	0	0
Payment of minimum tax withholdings on net share settlements of equity awards	0	0
Net cash used in financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	(5.1)	(0.6)
Net decrease in cash and cash equivalents	(8.8)	(11.2)
Cash and cash equivalents, beginning of period	160.2	113.5
Cash and cash equivalents, end of period	$ 151.4	$ 102.3