Leases (Lease Cost) (Details) $ in Millions	12 Months Ended
Mar. 31, 2020 USD ($)
Leases [Abstract]
Operating lease cost	$ 35.3
Finance lease cost
Amortization of right-of-use assets	3.0
Interest on lease liabilities	3.4
Total finance lease cost	6.4
Short-term lease cost	93.3
Total lease cost	$ 135.0

Finance Lease, Cost

No definition available.

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- Definition

Finance Lease Cost [Abstract]

+ References

No definition available.

+ Details

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- Definition

Amount of interest expense on finance lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
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-Section 45
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971

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- Definition

Amount of amortization expense attributable to right-of-use asset from finance lease.

+ References

+ Details

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- Definition

Amount of lease cost recognized by lessee for lease contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
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-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980

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- References

No definition available.

+ Details

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of short-term lease cost, excluding expense for lease with term of one month or less.

+ References

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