CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 1,285,500,000	$ 349,400,000	$ 570,600,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,143,500,000	1,153,300,000	1,215,600,000
Deferred income taxes	7,900,000	(138,900,000)	(490,300,000)
Share-based compensation expense related to equity incentive plans	210,200,000	198,300,000	170,200,000
Loss on settlement of debt	113,400,000	299,600,000	5,400,000
Amortization of debt discount	44,900,000	71,100,000	121,700,000
Impairment of intangible assets	3,000,000.0	0	2,200,000
Amortization of debt issuance costs	11,500,000	17,100,000	17,100,000
Other non-cash adjustment	(11,400,000)	(6,400,000)	(2,000,000.0)
Changes in operating assets and liabilities, excluding impact of acquisitions:
Increase in accounts receivable	(74,900,000)	(63,700,000)	(53,300,000)
(Increase) decrease in inventories	(177,800,000)	18,400,000	28,800,000
Increase in accounts payable and accrued liabilities	192,700,000	17,600,000	11,400,000
Change in other assets and liabilities	79,400,000	(16,700,000)	(13,100,000)
Change in income tax payable	14,800,000	17,400,000	(40,500,000)
Net cash provided by operating activities	2,842,700,000	1,916,500,000	1,543,800,000
Cash flows from investing activities:
Purchases of available-for-sale investments	0	0	(2,000,000.0)
Sales of available-for-sale investments and marketable equity securities	0	0	4,700,000
Proceeds from sales of assets	14,100,000	8,300,000	3,200,000
Investments in other assets	(121,700,000)	(89,000,000.0)	(71,500,000)
Capital expenditures	(370,100,000)	(92,600,000)	(67,600,000)
Net cash used in investing activities	(477,700,000)	(173,300,000)	(133,200,000)
Cash flows from financing activities:
Proceeds from issuance of senior notes	997,000,000.0	3,577,800,000	0
Repayment of senior notes	(1,000,000,000)	0	0
Proceeds from borrowings on Bridge Loan Facility	0	0	611,900,000
Repayment of Bridge Loan Facility	0	(615,000,000.0)	0
Payments on settlement of convertible debt	(424,700,000)	(2,611,400,000)	(615,000,000.0)
Deferred financing costs	(8,500,000)	(21,200,000)	(8,900,000)
Purchase of capped call options	0	(35,800,000)	0
Proceeds from sale of common stock	70,500,000	60,300,000	58,800,000
Tax payments related to shares withheld for vested RSUs	(84,200,000)	(64,600,000)	(68,100,000)
Repurchase of common stock	(425,600,000)	0	0
Payment of cash dividends	(503,800,000)	(388,300,000)	(350,100,000)
Capital lease payments	(800,000)	(600,000)	(800,000)
Net cash used in financing activities	(2,327,600,000)	(1,864,200,000)	(1,438,200,000)
Net increase (decrease) in cash and cash equivalents	37,400,000	(121,000,000.0)	(27,600,000)
Cash and cash equivalents, and restricted cash at beginning of period	280,000,000.0	401,000,000.0	428,600,000
Cash and cash equivalents, and restricted cash at end of period	317,400,000	280,000,000.0	401,000,000.0
Supplemental disclosure of cash flow information:
Restricted cash	0	0	25,000,000.0
ROU assets obtained in exchange of lease liabilities	27,500,000	65,600,000	24,800,000
Cash paid for interest	207,800,000	265,400,000	355,200,000
Cash paid for income taxes	141,400,000	87,300,000	101,300,000
Operating lease payments in operating cash flows	45,700,000	47,400,000	46,500,000
Revolving Credit Facility
Cash flows from financing activities:
Proceeds from borrowings on Revolving Credit Facility	4,176,000,000	3,966,000,000	1,026,000,000
Repayments of line of credit	(5,123,500,000)	(4,007,900,000)	(1,904,000,000)
Term Loan Facility
Cash flows from financing activities:
Repayments of line of credit	$ 0	$ (1,723,500,000)	$ (188,000,000.0)