Business Acquisitions (Schedule of Purchased Intangible Assets) (Details) - USD ($) $ in Millions			12 Months Ended
	Apr. 04, 2016	Aug. 03, 2015	Mar. 31, 2018
Core/developed technology
Business Acquisition [Line Items]
Purchased intangible assets			$ 7.1
Atmel Corporation
Business Acquisition [Line Items]
Useful life (in years)	9 years
Purchased intangible assets	$ 1,888.4
Atmel Corporation | Core/developed technology
Business Acquisition [Line Items]
Useful life (in years)	11 years
Purchased intangible assets	$ 1,075.0
Atmel Corporation | Customer-related
Business Acquisition [Line Items]
Useful life (in years)	6 years
Purchased intangible assets	$ 630.6
Atmel Corporation | Backlog
Business Acquisition [Line Items]
Useful life (in years)	1 year
Purchased intangible assets	$ 40.3
Atmel Corporation | Other intangible assets
Business Acquisition [Line Items]
Useful life (in years)	5 years
Purchased intangible assets	$ 1.8
Micrel Incorporated
Business Acquisition [Line Items]
Purchased intangible assets		$ 273.5
Micrel Incorporated | Core/developed technology
Business Acquisition [Line Items]
Useful life (in years)		10 years
Purchased intangible assets		$ 175.8
Micrel Incorporated | In-process technology
Business Acquisition [Line Items]
Purchased intangible assets		$ 21.0
Micrel Incorporated | Customer-related
Business Acquisition [Line Items]
Useful life (in years)		5 years
Purchased intangible assets		$ 71.1
Micrel Incorporated | Backlog
Business Acquisition [Line Items]
Useful life (in years)		1 year
Purchased intangible assets		$ 5.6
In-process technology | Atmel Corporation
Business Acquisition [Line Items]
Indefinite-lived Intangible Assets Acquired	$ 140.7