Borrowings and Credit Arrangements - Additional Information (Detail)					3 Months Ended					12 Months Ended
	Jun. 25, 2022	Sep. 28, 2020 USD ($)	Dec. 17, 2018 USD ($)	Jan. 19, 2018 USD ($)	Sep. 26, 2020 USD ($)	Dec. 28, 2019 USD ($) debt_instrument	Jun. 29, 2019 USD ($)	Mar. 30, 2019 USD ($)	Dec. 29, 2018 USD ($) $ / shares	Sep. 26, 2020 USD ($)	Sep. 28, 2019 USD ($)	Sep. 29, 2018 USD ($)	Sep. 30, 2017 USD ($)	Feb. 15, 2018 USD ($)	Oct. 10, 2017 USD ($)	Oct. 03, 2017 USD ($)	Feb. 14, 2013 USD ($)	Feb. 29, 2012 USD ($)	Nov. 18, 2010 USD ($)	Dec. 10, 2007 USD ($)
Debt Instrument [Line Items]
Proceeds from revolving credit line										$ 750,000,000.0	$ 480,000,000.0	$ 1,150,000,000.0
Debt extinguishment loss										0	800,000	45,900,000
Payment of debt issuance costs										0	2,700,000	23,500,000
Principal amount of borrowings					$ 1,000,000,000.0					1,000,000,000.0
Repayments of convertible debt										$ 0	$ 0	546,200,000
Deferred taxes, reacquisition of equity component									$ 3,800,000
Adjustments to APIC, equity component of convertible debt									13,400,000			$ (40,700,000)
Subsequent Event
Debt Instrument [Line Items]
Redemption price, percentage		40.00%
2018 Amended Credit Facility
Debt Instrument [Line Items]
Leverage ratio maximum										5.00
Interest coverage ratio										3.75
2018 Amended Credit Facility | Forecast
Debt Instrument [Line Items]
Leverage ratio maximum	4.50
2017 Credit Agreement
Debt Instrument [Line Items]
Debt extinguishment loss						$ (800,000)
Number of debt instruments | debt_instrument						2
Maximum range of present value of cash flow (percent)						10.00%
Third-party costs recorded as interest						$ 800,000
Payment of debt issuance costs						$ 1,900,000
Proceeds from issuance of debt										$ 1,800,000,000
Weighted-average interest rate (percent)											3.79%
Interest rate at end of period											3.43%
2017 Revolver
Debt Instrument [Line Items]
Proceeds from revolving credit line							$ 250,000,000.0
Prior Credit Agreement
Debt Instrument [Line Items]
Debt extinguishment loss									$ 1,000,000.0
Maximum range of present value of cash flow (percent)									10.00%
Third-party costs recorded as interest									$ 1,700,000
Payment of debt issuance costs									4,900,000
Repayments of secured debt										$ 1,320,000,000
Weighted-average interest rate (percent)												3.23%
Interest rate at end of period													3.74%
2022 Senior Notes
Debt Instrument [Line Items]
Debt extinguishment loss								$ 44,900,000
Maximum range of present value of cash flow (percent)								10.00%
Third-party costs recorded as interest								$ 2,600,000
Debt issuance costs reallocated upon debt modification								1,500,000
Debt discount reallocated upon debt modification								1,500,000
Convertible Notes | 2007 Notes
Debt Instrument [Line Items]
Debt instrument face amount																	$ 370,000,000.0	$ 500,000,000.0	$ 450,000,000.0	$ 1,725,000,000
Interest rate (percent)																				2.00%
2012 Notes
Debt Instrument [Line Items]
Debt instrument face amount									39,300,000
Repayments of convertible debt							$ 243,300,000		52,800,000
Repurchase amount								200,500,000
Deferred taxes, reacquisition of equity component								12,000,000.0
Debt instrument remaining to be redeemed									$ 5,500,000
Adjustments to APIC, equity component of convertible debt								$ 42,800,000
Conversion price (in dollars per share) | $ / shares									$ 31.175
Extinguishment of Debt, Amount													$ 117,900,000
2012 Notes | Period One
Debt Instrument [Line Items]
Redemption price as percentage of principle amount plus accrued and unpaid interest										100.00%
2012 Notes | Period Two
Debt Instrument [Line Items]
Redemption price as percentage of principle amount plus accrued and unpaid interest										100.00%
2013 Notes
Debt Instrument [Line Items]
Debt instrument face amount									$ 300,000
Repayments of convertible debt									244,100,000
Repurchase amount									$ 201,700,000
Extinguishment of Debt, Amount													$ 168,000,000.0
Securitization Program
Debt Instrument [Line Items]
Line of credit borrowing capacity					250,000,000.0					$ 250,000,000.0
Basis spread on variable rate										0.70%
Interest expense										$ 3,100,000	$ 7,100,000	$ 5,400,000
Term of accounts receivable securitization program										1 year
Accounts receivable from securitization					200,000,000.0					$ 200,000,000.0
Maximum borrowing under securitization program					200,000,000.0					200,000,000.0
Secured Term Loan | 2018 Amended Term Loan
Debt Instrument [Line Items]
Debt instrument face amount			$ 1,500,000,000
Secured Term Loan | 2018 Amended Term Loan | Minimum
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal Per Quarter			9,375,000
Debt Instrument, Estimated Due At Maturity After Scheduled Principal Payments					$ 1,200,000,000					$ 1,200,000,000
Secured Term Loan | 2018 Amended Term Loan | Maximum
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal Per Quarter			$ 28,125,000
Secured Term Loan | 2018 Amended Term Loan | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate			1.25%
Secured Term Loan | 2017 Term Loan
Debt Instrument [Line Items]
Debt instrument face amount																$ 1,500,000,000
Revolver
Debt Instrument [Line Items]
Interest rate (percent)					1.40%					1.40%
Line of Credit | 2018 Amended Revolver
Debt Instrument [Line Items]
Line of credit borrowing capacity			$ 1,500,000,000
Proceeds from revolving credit line			$ 350,000,000
Line of Credit | 2018 Amended Revolver | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate			1.25%
Line of Credit | 2017 Revolver
Debt Instrument [Line Items]
Line of credit borrowing capacity																$ 1,500,000,000
Senior Notes | 2025 Senior Notes
Debt Instrument [Line Items]
Interest rate (percent)					4.375%					4.375%
Senior notes principal amount				$ 600,000,000											$ 350,000,000
Principal amount of borrowings					$ 950,000,000					$ 950,000,000
Offering price, percent of face value				100.00%											100.00%
Senior Notes | 2025 Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Extinguishment of Debt, Amount		$ 970,800,000
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed		102.20%
Senior Notes | 2028 Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount					$ 400,000,000					$ 400,000,000
Interest rate (percent)					4.625%					4.625%
Proceeds from issuance of senior long-term debt				$ 1,000,000,000.0
Offering price, percent of face value					100.00%					100.00%
Redemption price, percentage										35.00%
Percentage of redemption price, second period					104.625%					104.625%
Percentage of redemption price, third period					102.312%					102.312%
Percentage of redemption price, fourth period					101.541%					101.541%
Percentage of redemption price, fifth period					100.77%					100.77%
Percentage redemption price, sixth period					100.00%					100.00%
Percentage price of principal amount for repurchase of senior notes										101.00%
Senior Notes | 2022 Senior Notes
Debt Instrument [Line Items]
Interest rate (percent)											5.25%
Senior notes principal amount														$ 1,000,000,000.0
Offering price of principal amount														1,040,000,000.00
Make whole provision														$ 37,700,000
Senior Notes | 2029 Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Interest rate (percent)		3.25%
Senior notes principal amount		$ 950,000,000.0
Offering price, percent of face value		100.00%
Redemption price, percentage		100.00%
Senior Notes | 2029 Senior Notes | Period One | Subsequent Event
Debt Instrument [Line Items]
Redemption price, percentage		103.25%
Senior Notes | 2029 Senior Notes | Period Two | Subsequent Event
Debt Instrument [Line Items]
Redemption price, percentage		101.625%
Senior Notes | 2029 Senior Notes | Period Three | Subsequent Event
Debt Instrument [Line Items]
Redemption price, percentage		100.813%
Senior Notes | 2029 Senior Notes | Period Four | Subsequent Event
Debt Instrument [Line Items]
Redemption price, percentage		100.00%
Senior Notes | 2029 Senior Notes | Period Five | Subsequent Event
Debt Instrument [Line Items]
Redemption price, percentage		101.00%
November 18, 2010 Original Notes | Convertible Notes
Debt Instrument [Line Items]
Debt instrument face amount																			$ 450,000,000.0
Interest rate (percent)																			2.00%
February 29, 2012 Original Notes | Convertible Notes
Debt Instrument [Line Items]
Debt instrument face amount																		$ 500,000,000.0
Interest rate (percent)																		2.00%
February 14, 2013 Original Notes | Convertible Notes
Debt Instrument [Line Items]
Debt instrument face amount																	$ 370,000,000.0
Interest rate (percent)																	2.00%
Convertible Notes Payable
Debt Instrument [Line Items]
Interest expense												$ 7,100,000
Securitization Program
Debt Instrument [Line Items]
Repayments of Debt					$ 250,000,000.0
Convertible Debt | 2042 Notes
Debt Instrument [Line Items]
Interest rate (percent)							2.00%