Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital in Excess of Par value of Common Stock	Retained Earnings	Accumulated Other Comprehensive Income
Balance (in shares) at Sep. 28, 2014		95.6
Balance at Sep. 28, 2014	$ 1,115.6	$ 19.1	$ 799.1	$ 298.6	$ (1.2)
Proceeds from exercise of stock options (in shares)		2.1
Proceeds from exercise of stock options	48.4	$ 0.4	48.0
Tax withholding on restricted stock units	(18.1)		(18.1)
Grants and cancellations of restricted share awards (in shares)		0.1
Grants and cancellations of restricted share awards	0.0	$ 0.0	0.0
Issuance of stock related to acquisition	3.8		3.8
Stock-based compensation expense	49.8
Stock-based compensation	49.8
Other comprehensive income, net of tax	(1.9)				(1.9)
Repurchase of outstanding common stock (in shares)		(2.7)
Repurchase of outstanding common stock	(75.0)	$ (0.5)	(74.5)
Net income	84.6			84.6
Balance (in shares) at Sep. 27, 2015		95.1
Balance at Sep. 27, 2015	1,207.2	$ 19.0	808.1	383.2	(3.1)
Proceeds from exercise of stock options (in shares)		2.2
Proceeds from exercise of stock options	4.6	$ 0.4	4.2
Shares Paid for Tax Withholding for Share Based Compensation		(1.2)
Tax withholding on restricted stock units	(42.5)	$ (0.2)	(42.3)
Grants and cancellations of restricted share awards (in shares)		0.8
Grants and cancellations of restricted share awards	0.0	$ 0.2	(0.2)
Issuance of stock related to acquisition (in shares)		15.8
Issuance of stock related to acquisition	474.5	$ 3.2	471.3
Issuance of stock awards related to acquisition (in shares)		0.1
Issuance of stock awards related to acquisition	15.7	$ 0.0	15.7
Stock-based compensation expense	101.0
Stock-based compensation	101.1
Other comprehensive income, net of tax	0.9				0.9
Stock-based compensation expense		0.8
Stock-based compensation expense		$ 0.1
Net income	(32.6)			(32.6)
Balance (in shares) at Oct. 02, 2016		113.6
Balance at Oct. 02, 2016	1,728.9	$ 22.7	1,357.8	350.6	(2.2)
Proceeds from exercise of stock options (in shares)		2.8
Proceeds from exercise of stock options	2.4	$ 0.6	1.8
Shares Paid for Tax Withholding for Share Based Compensation		0.1
Tax withholding on restricted stock units	(4.9)	$ 0.0	(4.9)
Stock-based compensation expense	89.0		89.0
Stock-based compensation	89.0
Other comprehensive income, net of tax	2.6				2.6
Stock-based compensation expense		0.0
Stock-based compensation expense		$ 0.0
Net income	176.3
Balance (in shares) at Oct. 01, 2017		116.3
Balance at Oct. 01, 2017	$ 1,994.3	$ 23.3	$ 1,443.7	$ 526.9	$ 0.4