Leases (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Sep. 30, 2025	Mar. 31, 2025
Lease assets and liabilities
Operating lease ROU assets		$ 135.4		$ 135.4			$ 97.2
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets, Noncurrent		Other Assets, Noncurrent			Other Assets, Noncurrent
Finance lease ROU assets	[1]	$ 6.9		$ 6.9			$ 6.9
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	[1]	Property, Plant and Equipment, Net		Property, Plant and Equipment, Net			Property, Plant and Equipment, Net
Operating lease liabilities, current		$ 23.3		$ 23.3			$ 18.0
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Current		Other Liabilities, Current			Other Liabilities, Current
Operating lease liabilities, noncurrent		$ 114.0		$ 114.0			$ 80.6
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Noncurrent		Other Liabilities, Noncurrent			Other Liabilities, Noncurrent
Finance lease liabilities, current		$ 0.6		$ 0.6			$ 0.5
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]		Long-Term Debt and Lease Obligation, Current		Long-Term Debt and Lease Obligation, Current			Long-Term Debt and Lease Obligation, Current
Finance lease liabilities, noncurrent		$ 1.9		$ 1.9			$ 2.2
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Long-Term Debt and Lease Obligation		Long-Term Debt and Lease Obligation			Long-Term Debt and Lease Obligation
Accumulated amortization		$ 4.7		$ 4.7			$ 4.2
Lease costs
Operating lease expense	[2]	12.4	$ 8.5	32.6	$ 23.1
Finance lease expense: Depreciation of ROU assets		0.1	0.1	0.4	0.4
Finance lease expense: Interest on lease liabilities		0.0	0.0	0.1	0.1
Total lease expense		12.5	8.6	33.1	23.6
Short-term lease expense		$ 3.1	$ 1.7	$ 8.1	$ 4.8
Manufacturing facility
Leases [Abstract]
Term of operating lease		5 years		5 years		7 years
Total future lease payments		$ 10.0		$ 10.0

[1] Finance right of use (“ROU”) assets were recorded net of accumulated amortization of $4.7 million and $4.2 million as of December 31, 2025 and March 31, 2025, respectively.

[2] For the three and nine months ended December 31, 2025, operating lease expense included short-term lease expense of $3.1 million and $8.1 million, respectively. For the three and nine months ended December 31, 2024, operating lease expense included short-term lease expense of $1.7 million and $4.8 million, respectively. Variable lease expense was not significant.