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