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RESTRUCTURING CHARGES - Summary of Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Restructuring Reserve [Roll Forward]
Balance as of March 31, 2020			$ 24.0
Provision for charges incurred during the nine-month period ended December 31, 2020	$ 30.0	$ 14.6	75.0	$ 199.1
Balance as of December 31, 2020	47.0		47.0
Less: Current portion (classified as other current liabilities)	46.0		46.0
Accrued restructuring costs, net of current portion (classified as other liabilities)	1.0		1.0
Cash Charges
Restructuring Reserve [Roll Forward]
Payments for charges incurred			(36.0)
Non-Cash Charges
Restructuring Reserve [Roll Forward]
Non-cash charges incurred during the nine-month period ended December 31, 2020			(2.0)
Cash payments for charges incurred in the fiscal year 2020 and prior \| Cash Charges
Restructuring Reserve [Roll Forward]
Payments for charges incurred			(14.0)
Severance
Restructuring Reserve [Roll Forward]
Balance as of March 31, 2020			20.0
Provision for charges incurred during the nine-month period ended December 31, 2020			68.0
Balance as of December 31, 2020	40.0		40.0
Less: Current portion (classified as other current liabilities)	39.0		39.0
Accrued restructuring costs, net of current portion (classified as other liabilities)	1.0		1.0
Severance \| Cash Charges
Restructuring Reserve [Roll Forward]
Payments for charges incurred			(35.0)
Severance \| Non-Cash Charges
Restructuring Reserve [Roll Forward]
Non-cash charges incurred during the nine-month period ended December 31, 2020			0.0
Severance \| Cash payments for charges incurred in the fiscal year 2020 and prior \| Cash Charges
Restructuring Reserve [Roll Forward]
Payments for charges incurred			(13.0)
Long-Lived Asset Impairment
Restructuring Reserve [Roll Forward]
Balance as of March 31, 2020			0.0
Provision for charges incurred during the nine-month period ended December 31, 2020			3.0
Balance as of December 31, 2020	0.0		0.0
Less: Current portion (classified as other current liabilities)	0.0		0.0
Accrued restructuring costs, net of current portion (classified as other liabilities)	0.0		0.0
Long-Lived Asset Impairment \| Cash Charges
Restructuring Reserve [Roll Forward]
Payments for charges incurred			0.0
Long-Lived Asset Impairment \| Non-Cash Charges
Restructuring Reserve [Roll Forward]
Non-cash charges incurred during the nine-month period ended December 31, 2020			(3.0)
Long-Lived Asset Impairment \| Cash payments for charges incurred in the fiscal year 2020 and prior \| Cash Charges
Restructuring Reserve [Roll Forward]
Payments for charges incurred			0.0
Other Exit Costs
Restructuring Reserve [Roll Forward]
Balance as of March 31, 2020			4.0
Provision for charges incurred during the nine-month period ended December 31, 2020			4.0
Balance as of December 31, 2020	7.0		7.0
Less: Current portion (classified as other current liabilities)	7.0		7.0
Accrued restructuring costs, net of current portion (classified as other liabilities)	$ 0.0		0.0
Other Exit Costs \| Cash Charges
Restructuring Reserve [Roll Forward]
Payments for charges incurred			(1.0)
Other Exit Costs \| Non-Cash Charges
Restructuring Reserve [Roll Forward]
Non-cash charges incurred during the nine-month period ended December 31, 2020			1.0
Other Exit Costs \| Cash payments for charges incurred in the fiscal year 2020 and prior \| Cash Charges
Restructuring Reserve [Roll Forward]
Payments for charges incurred			$ (1.0)