Leases (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Mar. 31, 2025
Lease assets and liabilities
Operating lease ROU assets		$ 107.1		$ 107.1		$ 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]	$ 7.0		$ 7.0		$ 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		$ 20.7		$ 20.7		$ 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		$ 86.7		$ 86.7		$ 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		$ 0.5		$ 0.5		$ 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		$ 2.1		$ 2.1		$ 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		$ 4.6		$ 4.6		$ 4.2
Lease costs
Operating lease expense	[2]	10.5	$ 7.7	20.2	$ 14.6
Finance lease expense: Depreciation of ROU assets		0.2	0.2	0.3	0.3
Finance lease expense: Interest on lease liabilities		0.1	0.1	0.1	0.1
Total lease expense		10.8	8.0	20.6	15.0
Short-term lease expense		$ 2.6	$ 1.8	$ 5.0	$ 3.1
Manufacturing Facility [Member]
Leases [Abstract]
Term of operating lease		7 years		7 years
Total future lease payments		$ 44.0		$ 44.0

[1] Finance right of use (“ROU”) assets were recorded net of accumulated amortization of $4.6 million and $4.2 million as of September 30, 2025 and March 31, 2025, respectively.

[2] For the three and six months ended September 30, 2025, operating lease expense included short-term lease expense of $2.6 million and $5.0 million, respectively. For the three and six months ended September 30, 2024, operating lease expense included short-term lease expense of $1.8 million and $3.1 million, respectively. Variable lease expense was not significant.