Restructuring and Other (Severance Liability Rollforward) (Details) - Severance liability - USD ($) $ in Millions	6 Months Ended
Sep. 30, 2021	Sep. 30, 2020
Restructuring and Other Severance Liability
Beginning balance	$ 5.7	$ 11.1
Accruals	3.8	10.6
Severance payments	(6.5)	(10.8)
Ending balance	3.0	$ 10.9
Accounts Payable and Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Remaining severance liability, expected to be paid in next 12 months	$ 3.0

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

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-Publisher FASB
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Carrying amount as of the balance sheet date of known and estimated obligations associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid in the next twelve months or in the normal operating cycle if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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