Segment Information - Schedule of Reconciliation of Total Segment Profit to the Company's Loss Before Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Company’s total segment profit	$ 27.0	$ 130.7	$ 123.9	$ 222.8
Adjusted depreciation and amortization	(3.2)	(2.4)	(6.7)	(5.2)
Restructuring and other	(7.2)	(4.9)	(34.9)	(9.0)
Adjusted share-based compensation expense	(15.3)	(17.4)	(27.9)	(29.0)
Operating income (loss)	(34.8)	76.0	(19.1)	113.0
Interest expense	(63.0)	(51.7)	(121.6)	(101.6)
Interest and other income	3.3	2.9	8.4	5.1
Other expense	(13.8)	(10.0)	(15.2)	(13.7)
Loss on extinguishment of debt	(0.5)	0.0	(1.5)	0.0
Loss on investments, net	0.0	(1.6)	0.0	(1.7)
Equity interests income (loss)	(0.1)	1.8	0.8	1.5
Income (loss) before income taxes	(108.9)	17.4	(148.2)	2.6
Operating Segments
Segment Reporting Information [Line Items]
Company’s total segment profit	27.0	130.7	123.9	222.8
Corporate
Segment Reporting Information [Line Items]
Corporate general and administrative expenses	(28.1)	(26.5)	(59.2)	(51.0)
Corporate and Reconciling Items
Segment Reporting Information [Line Items]
Adjusted depreciation and amortization	(3.2)	(2.4)	(6.7)	(5.2)
Restructuring and other	(7.2)	(4.9)	(34.9)	(9.0)
COVID-19 related benefit (charges) included in direct operating expense	0.0	0.5	2.1	0.4
Content charges	0.0	(0.4)	0.0	(0.8)
Unallocated rent cost included in direct operating expense	(5.2)	0.0	(10.5)	0.0
Adjusted share-based compensation expense	(15.3)	(17.4)	(27.9)	(29.0)
Purchase accounting and related adjustments	$ (2.8)	$ (3.6)	$ (5.9)	$ (15.2)