Fair Value Measurements (Tables)

12 Months Ended

Oct. 01, 2017

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on a Recurring Basis

Assets and Liabilities Measured at Fair Value on a Recurring Basis (in millions):

			Fair Value Measurements at Reporting Date Using
	Balance at Oct 1, 2017		Quoted Prices in Active Markets for  Identical Assets (Level 1)		Significant  Other Observable  Inputs (Level 2)		Significant Unobservable  Inputs (Level 3)
Assets:
Cash and cash equivalents	$	2,462.3	$	2,462.3	$	—	$	—
Short-term investments:
Available-for-sale securities
Agency obligations	7.5		—		7.5		—
Commercial paper	2.0		—		2.0		—
Corporate debt securities	49.4		—		49.4		—
Foreign government obligations	7.1		—		7.1		—
U.S. government treasury securities	81.4		81.4		—		—
Mortgage and other asset-backed securities	2.0		—		2.0		—
Certificates of deposit	2.3		—		2.3		—
Total available-for-sale securities	151.7		81.4		70.3		—
Trading securities	76.9		76.9		—		—
Total short-term investments	228.6		158.3		70.3		—
Prepaid expenses and other current assets:
Derivative assets	13.4		0.1		13.3		—
Long-term investments:
Available-for-sale securities
Agency obligations	21.8		—		21.8		—
Corporate debt securities	207.4		—		207.4		—
Auction rate securities	5.9		—		—		5.9
Foreign government obligations	17.1		—		17.1		—
U.S. government treasury securities	127.4		127.4		—		—
State and local government obligations	7.0		—		7.0		—
Mortgage and other asset-backed securities	155.7		—		155.7		—
Total long-term investments	542.3		127.4		409.0		5.9
Other long-term assets:
Derivative assets	24.4		—		24.4		—
Total assets	$	3,271.0	$	2,748.1	$	517.0	$	5.9
Liabilities:
Accrued liabilities:
Derivative liabilities	$	16.4	$	2.5	$	13.9	$	—
Other long-term liabilities:
Derivative liabilities	22.1		—		22.1		—
Total liabilities	$	38.5	$	2.5	$	36.0	$	—

			Fair Value Measurements at Reporting Date Using
	Balance at Oct 2, 2016		Quoted Prices in Active Markets for  Identical Assets (Level 1)		Significant  Other Observable  Inputs (Level 2)		Significant Unobservable  Inputs (Level 3)
Assets:
Cash and cash equivalents	$	2,128.8	$	2,128.8	$	—	$	—
Short-term investments:
Available-for-sale securities
Agency obligations	1.3		—		1.3		—
Commercial paper	2.6		—		2.6		—
Corporate debt securities	34.2		—		34.2		—
Foreign government obligations	5.5		—		5.5		—
U.S. government treasury securities	15.8		15.8		—		—
State and local government obligations	0.5		—		0.5		—
Certificates of deposit	5.8		—		5.8		—
Total available-for-sale securities	65.7		15.8		49.9		—
Trading securities	68.7		68.7		—		—
Total short-term investments	134.4		84.5		49.9		—
Prepaid expenses and other current assets:
Derivative assets	27.7		3.1		24.6		—
Long-term investments:
Available-for-sale securities
Agency obligations	44.4		—		44.4		—
Corporate debt securities	459.3		—		459.3		—
Auction rate securities	5.7		—		—		5.7
Foreign government obligations	46.7		—		46.7		—
U.S. government treasury securities	358.2		358.2		—		—
State and local government obligations	57.5		—		57.5		—
Mortgage and other asset-backed securities	169.9		—		169.9		—
Total long-term investments	1,141.7		358.2		777.8		5.7
Other long-term assets:
Derivative assets	6.4		—		6.4		—
Total assets	$	3,439.0	$	2,574.6	$	858.7	$	5.7
Liabilities:
Accrued liabilities:
Derivative liabilities	$	18.0	$	1.7	$	16.3	$	—
Other long-term liabilities:
Derivative liabilities	71.6		—		71.6		—
Total	$	89.6	$	1.7	$	87.9	$	—