Intangible Assets and Goodwill (Tables)

12 Months Ended

Mar. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets, Indefinite-Lived

Intangible assets consist of the following (in millions):

	March 31, 2020
	Gross Amount		Accumulated Amortization			Net Amount
Core and developed technology	$	7,331.9	$	(1,924.6	)	$	5,407.3
Customer-related	903.6		(674.7		)	228.9
In-process research and development	8.8		—			8.8
Distribution rights and other	126.0		(68.7		)	57.3
Total	$	8,370.3	$	(2,668.0	)	$	5,702.3

	March 31, 2019
	Gross Amount		Accumulated Amortization			Net Amount
Core and developed technology	$	7,339.2	$	(1,102.2	)	$	6,237.0
Customer-related	917.1		(544.0		)	373.1
In-process research and development	7.7		—			7.7
Distribution rights and other	81.4		(13.6		)	67.8
Total	$	8,345.4	$	(1,659.8	)	$	6,685.6

Schedule of Intangible Assets, Finite-Lived

Intangible assets consist of the following (in millions):

	March 31, 2020
	Gross Amount		Accumulated Amortization			Net Amount
Core and developed technology	$	7,331.9	$	(1,924.6	)	$	5,407.3
Customer-related	903.6		(674.7		)	228.9
In-process research and development	8.8		—			8.8
Distribution rights and other	126.0		(68.7		)	57.3
Total	$	8,370.3	$	(2,668.0	)	$	5,702.3

	March 31, 2019
	Gross Amount		Accumulated Amortization			Net Amount
Core and developed technology	$	7,339.2	$	(1,102.2	)	$	6,237.0
Customer-related	917.1		(544.0		)	373.1
In-process research and development	7.7		—			7.7
Distribution rights and other	81.4		(13.6		)	67.8
Total	$	8,345.4	$	(1,659.8	)	$	6,685.6

Schedule of Projected Amortization Expense

The following is an expected amortization schedule for the intangible assets for fiscal 2021 through fiscal 2025, absent any future acquisitions or impairment charges (in millions):

Fiscal Year Ending March 31,	Projected Amortization Expense
2021	$	985.8
2022	$	903.3
2023	$	693.1
2024	$	617.6
2025	$	501.4

Schedule of Amortization Expense by Intangible Asset Class

Amortization expense attributed to intangible assets are assigned to cost of sales and operating expenses as follows (in millions):

	Year Ended March 31,
	2020		2019		2018
Amortization expense charged to cost of sales	$	8.9	$	9.6	$	6.1
Amortization expense charged to operating expense	1,037.8		686.2		486.1
Total amortization expense	$	1,046.7	$	695.8	$	492.2

Schedule of Goodwill Activity

Goodwill activity for fiscal 2020 and fiscal 2019 was as follows (amounts in millions):

	Semiconductor Products Reporting Unit		Technology Licensing Reporting Unit
Balance at March 31, 2018	$	2,279.8	$	19.2
Additions due to the acquisition of Microsemi	4,364.9		—
Balance at March 31, 2019	$	6,644.7	$	19.2
Additions	0.9		—
Balance at March 31, 2020	$	6,645.6	$	19.2