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Business Acquisitions - Narrative, Microsemi (Details) - USD ($) $ in Millions		12 Months Ended
	May 29, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Acquisition of Microsemi, net of cash acquired		$ 0.0	$ 7,850.6	$ 0.0
Microsemi Corporation
Business Acquisition [Line Items]
Cash paid for shares	$ 8,190.0
Non cash consideration of certain share-based payment awards	53.9
Total consideration transferred	8,240.0
Liabilities assumed	3,232.6
Payments to acquire businesses portion funded by additional line of credit borrowings	8,100.0
Transaction and other fees incurred in transaction	$ 22.0
Useful life	13 years
Deferred tax liabilities	$ 856.7
Microsemi Corporation \| Backlog
Business Acquisition [Line Items]
Useful life	1 year
Microsemi Corporation \| Term Loan Facility
Business Acquisition [Line Items]
Payments to acquire businesses portion funded by additional line of credit borrowings	$ 3,000.0
Microsemi Corporation \| Senior Secured Notes
Business Acquisition [Line Items]
Payments to acquire businesses portion funded by additional line of credit borrowings	2,000.0
Microsemi Corporation \| Revolving Credit Facility
Business Acquisition [Line Items]
Payments to acquire businesses portion funded by additional line of credit borrowings	3,100.0
Microsemi Corporation \| Other Liabilities
Business Acquisition [Line Items]
Acquisition of Microsemi, net of cash acquired	$ 2,060.0